Final Report Summary - H-HOUSE (Healthier Life with Eco-innovative Components for Housing Constructions)
Executive Summary:
In recent years, significant efforts have been undertaken to reduce the CO2 emissions associated to the building sector. As the population increases, more buildings are required and thus more natural resources and energy are consumed during construction and operation. Coupled to the necessity to reduce the energy consumption, buildings are becoming heavily insulated and airtight leading to changes of the indoor environment. As people spend more and more time indoors, the occupant’s health, wellbeing and productivity is greatly affected.
The project H-House, ‘Healthier Life with Eco-innovative Components for Housing Constructions’, aimed to develop a number of multifunctional and flexible components for the building envelope and internal walls, for new buildings and renovation. Strongly focused on environmental aspects (such as reduced embodied energy and carbon footprint) and human comfort (thermal and acoustic), the main objectives were to increase the durability and energy-efficiency of materials and components and a healthier indoor environment by preventing the accumulation of pollutants and reducing noise.
Technical aims of the project were to develop lightweight façade elements based on Textile Reinforced Concrete (TRC) and Ultra-High Performance Concrete (UHPC). These elements have an integrated non-flammable insulation based on Foam Concrete (FC) containing aerogels and Autoclaved Aerated Concrete (AAC) optimized with regards to the use of natural resources and embodied energy. Application, of photocatalytic and hydrophobic surfaces contributes to the reduction of pollutants and prevention of harmful microbiological growth as well as towards easy-to-clean/self-cleaning facades. Indoor, the use of natural materials together with aerogels, improves temperature and moisture control as well and enhances reduction of the air pollution by absorption and photocatalytic decomposition of VOCs.
Project Context and Objectives:
1) Project context
The concept of H-House provides eco-innovative approaches on material level and on component level. The approach on the material level is to use existing knowledge and technology for further development of the physical properties concerning functionalization of surfaces, modification of water vapour permeability and moisture absorption capacity, reduction of moisture transport, increase of heat transfer resistance and reduction of embodied energy. The approach on the component level is to innovatively combine the developed materials to composite building elements for the building envelope and for internal walls / partitions, which are improved in functionality and in energy and acoustic efficiency, providing an improved indoor environment and easy disassembling for recycling.
The project consists of seven work packages (WP), where WP2 to WP5 are of technical and scientific content. WP2 is dedicated to material development, WP3 to the design and testing of building components. In WP4 the properties of the materials and the performance of the components is modelled and assessed towards the requirements. In WP5 the production technologies of the developed components are enhanced and prototype components are produced and exposed to the public. WP6 is entirely dedicated to life cycle assessment and the impact of the materials on human health. WP7 is dedicated to dissemination activities, market analysis and business plan.
2) Project objectives
The project concept addresses several objectives concerning the improvement of the indoor environment and the increased energy efficiency of building components:
a) To prevent accumulation of pollutants and harmful microbiological growth in the interior space by:
- use of building materials free of dangerous substances,
- photocatalytic decomposition and/or absorption of dangerous substances;
b) To improve moisture indoor control by:
- prevention of moisture ingress from exterior (building envelope),
- increase of moisture buffer capacity in the interior;
c) To improve thermal and noise protection of the indoor environment by:
- decrease of moisture flux into the building envelope and thus prevention of decreased insulation effect,
- use of acoustic damping effects of layered composites;
d) To develop and suggest new and efficient production technologies for low embodied energy building elements by:
- new light-weight sandwich panels for new buildings and half-sandwich panels for retrofitting with improved thermal and acoustic properties based on Textile Reinforced Concrete (TRC) with insulation of low density foamed concrete,
- new multifunctional façade elements with improved thermal and acoustic properties based on ‘green’ Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC) and low density foamed concrete,
- lightweight façade elements with improved thermal and acoustic properties based on hydrothermally produced (autoclaved) ‘green’ UHPFRC and Aerated Autoclaved Concrete (AAC) insulation material,
- new internal wall / partition systems based on earth, wood, wood fibre and cellulose;
e) To increase the durability and thus to decrease the maintenance costs of building envelops by
- activation of self-cleaning properties (application of photocatalytic material and/or micro-structural modification of surfaces in combination with hydrophilic / hydrophobic surface treatment),
- decrease of moisture flux into the building envelope due to densified micro-structure;
f) Implementation of the developed solutions in building components by:
- ensuring the effective transferability to precast and ready-mixed concrete companies across Europe,
- promotion of cost effective new materials or building components that are easy to produce and easy to assemble,
- designing at an early stage the recycle scenario, i.e. the separation of different materials after the use of the composite shall be possible without causing extraordinary expenses,
- introduction of life cost and life time estimation; this in turn requires that the material and building components can be described in a standardized way,
- contribution to standardization of the materials.
Project Results:
1 New Test methodologies
For the measurement of the materials’ emission and adsorption a special test chamber was designed. The advantage of test chamber is the possibility to use the complete bottom of the chamber to expose the material’s surface for emission/adsorption following international test standards. The special design allows for testing of single materials and composites consisting of several layers with a total thickness of up to approximately 15 cm, which makes it possible to investigate almost real scale building component setups.
Moreover, a simple screening test was used to estimate the materials’ VOC emissions in a relatively short time. The test is based on thermal extraction from the test samples. The gaseous extracts containing the analytes are collected on adsorbent tubes that are finally analysed using TDS-GC/MS. This test method could be used to quickly screen VOC emissions from construction wastes, e.g. volatile components of chemical concrete admixtures, which was identified as exploitable foreground.
2 Material development
2.1 Aerogel-modified Earth Plaster
Different types of aerogel and earth plaster have been investigated in order to select the most promising starting materials for the incorporation of aerogels in earth plasters to enhance the water vapour sorption activity. Resulting from preliminary application tests two types of hydrophilic aerogel (one powder with a maximum particle size of 100 µm and one granulate with a maximum particle size of 0.5 mm) and plant fibre reinforcement (to reduce drying shrinkage of the plaster) were proposed. The aerogel powder demonstrated a much better water vapour sorption activity than the granulated aerogel by means of sorption rate and total sorption capacity. On the other hand, the granulated aerogel is generally more convenient to work with since it is easier to pour and dusting is less pronounced. However, earth plasters modified with each type of aerogel showed similar water vapour sorption activities that were significantly improved compared to the pure earth plaster, i.e. the water vapour sorption was increased by 11-14% after 2 hours and 18-22% after 12 hours.
2.2 Textile-Reinforced Concrete (TRC)
The high-performance fine-grained concrete mix designed for TRC was further optimized and up-scaled according to the materials and equipment available for the prototype demonstrator production. The concrete mix of the TRC consists of a binder blend of CEM II/A-V 52.5 and fly ash and demonstrates acceptable frost resistance according to high Swedish requirements with a compressive strength of 109 MPa (at 28 d). The maximum aggregate size is 5 mm. The textile reinforcement that has been selected as the final solution for the TRC panels is a carbon textile grid. The selection was based primarily on the superior alkali resistance of the carbon material, which indicates promising long-term durability of the reinforcement in a concrete matrix. The flexural strength of the TRC is 7 MPa at first cracking and approximately 70 MPa at maximum load.
2.3 Ultra-High Performance Concrete (UHPC)
The UHPC developed in the project is based on the Nanodur technology. The boundary conditions for the development were set by a minimum compressive strength of the UHPC of 100 MPa, which was considered as sufficient for its use for the production of self-supporting composite facade elements. Reduction of embodied energy was achieved by replacement of Portland cement with supplementary cementitious materials (SCM). Currently the Portland cement content can be reduced to approximately 30 wt.-% of the binder, which is equivalent to 190 kg/m3 in the UHPC. Similar to Nanodur the two newly developed binder compositions are ready-to-use products and offered to the market as ‘TP H-House Compound GREY’ and ‘TP H-House Compound WHITE’.
The UHPC was used without fiber reinforcement that was abandoned in the course of the project because it did not improve significantly the mechanical performance of the UHPC in case of glass and carbon fibers. The use of steel fibers was neglected for aesthetical reasons (rust stains on UHPC surface).
In a series of tests the UHPC demonstrated acceptable durability performance with regard to its use in building envelope applications (high freeze-thaw resistance, very slow chloride migration, very slow carbonation).
2.4 Foam Concrete (FC)
An inorganic light-weight insulation material was developed based on foam concrete FC. For increased thermal performance the aerogel was incorporated. Additionally polymer fibres reduced the brittleness of the material. The material has the following properties:
- Density: 120-150 kg/m3
- Compressive strength: 100-300 kPa
- Thermal conductivity: 40-43 mW/(m K) without aerogel, 29-32 mW/(m K) with aerogel.
2.5 Autoclaved Aerated Concrete (AAC)
The development of AAC was based on the Multipor® technology (density: 115 kg/m3, thermal conductivity: 47 mW/(m K)) with regard to energy efficiency considerations. As the environmental impact of AAC production is dominated by the use of thermal energy and by the manufacture of the binders (cement and quicklime), emphasis was put on the replacement of energy-intensive Portland cement (CEM I) by alternative binders with lower embodied energy. Several blended cements were regarded as suitable for the manufacture of high-quality light-weight AAC from a mineralogical point of view and with regards to thermal performance. However, strength requirements were met only with Portland slag cement (CEM II/A-S 52.5 N) and blastfurnace cement (CEM III/A 42.5 N).
2.6 Self-cleaning surfaces
The surface of the materials for the building envelope, i.e. Textile Reinforced Concrete (TRC) and Ultra-high Performance Concrete (UHPC) forming the external shell (protective layer) of the new composite façade elements, was modified. Two approaches for surface modifications were followed to provide self-cleaning properties: photocatalytic activation and activation of the Lotus effect.
Photocatalytic activation was generally created using photoactive titanium dioxide (TiO2). For the TRC, TiO2 was either used as bulk additive to the concrete or as coating. A special form of application was the use of a TiO2 suspension distributed on the formwork before concrete cast. An optimum level of TiO2 addition into a fly ash based concrete has been established for both TiO2 products investigated at 4-8% weight replacement of cement. Variations of the reactivity at similar TiO2 dosage levels were due to different degrees of TiO2 dispersion in the concrete matrix.
The application of the TiO2 suspension on the hardened cement paste, i.e. as coating, resulted in a much higher photocatalytic activity than the bulk addition of TiO2. Also, the use of TiO2 dispersion directly on the formwork resulted in a very high photocatalytic activity. However, this method proved to aesthetically negatively affect the concrete surface.
The UHPC was photocatalytically activated by bulk addition of TiO2. It was demonstrated that moderate dosages, i.e. by addition of 1% TiO2 powder related to the total weight of solids (22 kg/m3), are sufficient to distinctly activate the photocatalytic self-cleaning effect. With these low dosages and the thin external layer of the UHPC composite facade elements the bulk addition of photoactive TiO2 might become also economically feasible. The durability of the photocatalytically activated self-cleaning was demonstrated by monitoring of UHPC samples subjected to outdoor weathering.
The second approach towards self-cleaning was to create a super hydrophobic UHPC surface. Super hydrophobicity is usually associated with contact angles of a water droplet ≥ 140-150°, which is often referred to as Lotus effect, and is the result of the coaction of a special micro texture of the surface and a chemical water repellence. Very good results were achieved by creating an adequate micro-structured UHPC surface through casting the UHPC on technical fabrics. In a later stage of the project, the micro structure was transferred to a rubber formliner, which was then used as the substrate for the UHPC and made repeated, and thus allowing more economic casts. The chemical water repellence was achieved by application of silane-based hydrophobic agents. It was demonstrated that the most efficient way to use the hydrophobic agent is its application on the micro-structured substrate before the concrete cast. This newly developed method was subject of a patent application. The durability of the super hydrophobic UHPC surface was demonstrated by artificial weathering tests and by monitoring of UHPC samples subjected to outdoor weathering.
3 Building components
3.1 Concept and Design
- Architectural design
An architectural design has been proposed based on a real case scenario in urban context for new construction application to present the possibilities of the developed sandwich facade elements and to highlight the boundaries of the systems including aesthetical aspects and constructional requirements like positioning of joints between elements and around openings joints, connectors and anchorage systems as well as a revised design regarding the dimensioning of the precast elements.
The development of floor layouts is taking into consideration an appropriate mix of different apartment sizes based on the definition of basic pattern suitable for optimization for most flexible floor plan layouts. Floor layouts have been designed as a case scenario that is mainly suitable for the development of council housing.
The design of the facade has been further extended with regards to structural details such as anchorage systems, connections and joints as well as a simplification of the panel typologies down to the basic dimensions of 3.6 m and 4.8 m panels in order to optimise its prefabrication ability. At the same time a wide range of different infill options (independent framework constructions) allow for the installation of numerous window typologies and facade applications to form an individualistic appearance of the building. Considerations with regards to maximisation of daylight have influenced the design proposals with a ratio to 38.5% at South façade and 22.3% to north facade to minimise heat losses in wintertime and solar gains in summer time.
- Partitions based on natural materials
The development of innovative solutions for eco-friendly, low carbon, low-emitting internal partition walls with high climate control capacities was finalised and guidelines for production technology of partition walls were prepared. A comprehensive number of wall designs, has been assessed and compiled in a matrix serving as a tool for comparison and evaluation. The matrix includes solid wall and stud wall constructions that might be used to create partitions located inside a flat as well as flat separation walls (mainly non loadbearing).
- TRC-FC composite facade elements
Two precast composite light-weight concrete facade elements are proposed, which incorporate TRC and FC:
1) Composite element consisting of two layers made of TRC for the external facing layer and FC for the insulation layer. The element is self-supporting and can be applied for refurbishment. The thickness of the insulation layer can be prescribed according to the desired thermal performance.
2) Composite element consisting of three layers made of TRC for the external facing layer and the internal load bearing layer and FC for the intermediate insulation layer. The element is load bearing and can be applied in new construction. The thickness of the facing TRC layer is 30 mm due to the element geometry and required embedment depth of the connectors.
The anticipated structural performance of the TRC-FC composite element was designated as a partially composite wall with load bearing internal TRC layer. Newly developed glass fibre reinforced polymer (GFRP) connectors were incorporated to provide a) a mechanical connection between the layers and b) a load transferring mechanism. Guidelines for the production technology of TRC-FC composite elements were prepared.
- UHPC-FC/AAC composite facade elements
A non-loadbearing box-shaped element made of an external UHPC shell was developed. The external shell protects and supports the insulation layer (FC or AAC). Guidelines for the production technology of UHPC-FC/AAC composite elements were prepared. The element configuration was implemented in order to optimise the hygrothermal behaviour of the elements following the different geographic/climatic scenarios assigned.
The box-shaped concept is a simple and robust solution for the facade elements. Besides the good structural performance, the concept enables efficient protection of the insulation material during transport, installation and use. Additionally, due to the absence of reinforcement and connectors through the insulation, the production technology does not involve major labour-intensive tasks, which is desirable for industrial production. A system of anchorage of the composite element was developed. The reliability of transport anchors and support anchors as well as the resistance of anchor rails to support window frames was assessed. The production technology of the element in two-step was implemented through a different selection of concrete material properties, including micro-structuring of the surface with rubber formliners.
Three alternatives of UHPC-insulation combinations were assessed. The use of FC and AAC blocks as insulation material proved to be reliable solutions, whereas the autoclaving of prefabricated UHPC/AAC-slurry elements showed detrimental effects on the quality of the UHPC surface (staining) and on the bond between UHPC and AAC.
3.2 Performance assessment
- Partitions based on natural materials
Based on numerous investigations on the material level, a comprehensive number of wall build-ups was assessed towards hygrothermal, structural and acoustic performance. It was demonstrated that earthen materials used either as plaster or as boards for dry walls bear high potential in improving the indoor environment quality because of their superior water vapour sorption activity, which is associated with an improved sorption of VOCs compared to conventional construction materials, such as gypsum. Moreover, in the case of stud wall constructions in was demonstrated that an adequate insulation material, e.g. wood fibre mats, can contribute significantly to a favourable hygrothermal activity of the partition wall.
The structural integrity was proved for a variety of eco-innovative solutions, such as earth and wood fibre boards for stud constructions and flax or straw panels for solid walls. In some cases, a lack of sufficient resistance against light console loads was observed with very light-weight earth and wood fibre boards. However, this disadvantage can be compensated by connecting consoles directly to the studs of the wall.
The assessment of the sound insulation properties revealed that 9 out of 28 tested partition wall build-ups cannot be used as separations between dwellings. However, this assessment was based on small-scale acoustic tests, which is restraining the validity of the assessment.
- Composite facade elements
TRC-FC and UHPC-AAC/FC composite elements have been assessed concerning their load-bearing capacity under the action of self-weight and wind load. With the help of numerical modelling of the full scale composite elements, ultimate limit state loads have been determined for bending and shear failure, which were subsequently verified in lab-scale experimental investigations. The experimental results showed that the actual load-bearing performance of the elements is well above the required load-bearing capacity. The experimental results confirmed also that the proposed solutions for transport anchors and anchorage for windows/doors, to be cast in the UHPC elements, are able to carry the design load assigned.
The assessment of the hygrothermal performance of the façade elements, which was based on experimentally obtained material characteristics and numerical modelling, revealed that the current design of the proposed solutions meets well the requirements regarding thermal transmittance (thermal bridges considered):
- UHPC-AAC element: U = 0.14 W/(m2 K), thickness of insulation: 350 mm
- UHPC-FC element: U = 0.11 W/(m2 K), thickness of insulation: 350 mm
- TRC-FC sandwich element: U = 0.26 W/(m2 K), thickness of insulation: 150 mm.
The numerical analysis of the moisture and heat flow through the facade elements showed that the risk of moisture condensation inside the elements is very low, even though thermal bridges were detected, which are inevitable due to the edges of the UHPC box design and the connectors in the TRC element.
The assessment of the acoustic performance showed that a joint between two elements is significantly affecting the sound insulation. Nevertheless, all types of H-House facade elements show a very good performance with sound insulation values well above the limit of the highest sound insulation class according to European recommendations. The comparison to German and Polish requirements revealed medium to high sound insulation performance of all types of the H-House facade elements tested.
Experimental tests according to European protocol confirmed the durability of the proposed H-House solutions for the building envelope.
3.3 Life Cycle Assessment and Life Cycle Cost Analysis
The Life Cycle Assessment (LCA) in the frame of the H-House project was an iterative process, starting with a global scope definition and the establishment of a methodological framework. In a second step, Life Cycle Inventories (LCI) were created and continuously updated according to the actual state of the art concerning design and material properties. Finally, a selection of innovative building components developed during the H-House project has been studied regarding their life cycle performance:
- TRC-FC sandwich facade element with photocatalytic properties
- UHPC-AAC facade element with photocatalytic properties
- UHPC-FC facade element with super-hydrophobic properties
- Partition wall based on natural materials (wood fibre board on timber stud construction with internal wood fibre insulation and earth plaster rendering).
Several comparative studies have been conducted on both environmental life cycle impacts (i.e. through LCA) and global costs (i.e. through LCC) taking into account different conventional scenarios, location of use and service life. The life cycle impact assessments were performed for seven categories: non-renewable energy, climate change, acidification, terrestrial eutrophication, freshwater eutrophication, freshwater ecotoxicity and land use. Non-renewable energy and climate change were considered as the most important impacts and in most cases, similar trends were observed for both indicators.
The LCA has been performed for facade elements of the same U-value. In contrast, the LCC of the H-House solutions were compared to the LCC of the reference walls having a lower thermal performance matching with what is commonly installed nowadays in the location considered. As a consequence, an additional consumption for the heating of the building is accounted for in the conventional scenario. In case of the partition wall conventional gypsum plasterboard dry lining wall was taken into account as reference scenario.
The TRC-FC sandwich element was compared to a conventional reinforced concrete sandwich element with EPS insulation and to a cast-on-site reinforced concrete wall with rock wool insulation. The most important observation is that the higher environmental impact of the innovative TRC-FC sandwich element in the production stage is compensated by its lightweight contributing in reducing substantially the impact of its transport and installation as well as its end of life treatment. Moreover, the aerogel has a major influence on the environmental impact of the FC that is higher than the ones of EPS and rock wool. When the FC is produced without aerogel its environmental impact is lower than EPS. The costs for production and installation of the innovative TRC-FC sandwich element are, due to the novelty of the proposed production technology, higher than for the conventional reference scenarios where the production lines are well established. But, taking into account realistic assumptions on the real discount rate and the growth rate of energy price the lower heating costs can compensate the investment costs with lower global costs at the end of lifetime (after 50 years) compared to both reference scenarios.
The UHPC-AAC and the UHPC-FC elements were compared to a conventional reinforced concrete cladding with rock wool insulation. In both cases the environmental impact of the innovative UHPC element is higher than the conventional concrete solution. Moreover, the global costs of both innovative UHPC element variations are superior to the one of the conventional cladding scenario, whatever the real discount rate and growth rate of energy price are, among plausible values. This means that the investment costs of the innovative UHPC elements are so high that they cannot be compensated by lower costs for heating.
However, it has to be pointed out that (i) different sources were used to create the cost inventories, which might introduce a bias in the assessment, and (ii) the cost inventories are based on conservative assumptions, i.e. the production and installation costs of the innovative light-weight facade elements have been assumed rather high in comparison to the conventional solutions. Moreover, the higher durability of the UHPC in comparison to the conventional concrete was not considered in the LCA/LCC. Due to the lack of reliable data in both innovative solution scenario and conventional reference scenario the same lifetime was assumed without any repair of the conventional concrete. Superior performance (self-cleaning) was considered with lower or no costs for cleaning compared to the conventional solutions, but again, due to the lack of database rather low costs for the cleaning of the conventional concrete have been assumed.
3.4 Impact on Human Health
The human impact from indoor toxic pollutants was evaluated based on measured emission rates of the construction materials and the characterisation factors of the substances emitted from the samples. The impact was calculated for carcinogenic and non-carcinogenic substances, and for household and occupational scenarios. Thus, it was possible to complete all the objectives concerning impacts assessment on human health. Nevertheless, beyond practical results, strong emphasis was done to cover methodological aspects. Therefore, the studies performed in the frame of H-House enable to address in detail critical questions and to bring new insight for applying LCA of building products including impact assessment on human health.
The most relevant model to assess impact on human health in LCA for indoor emissions is the USEtox model. It is a consensual model, largely used in LCA, with an extended database of characterisation factors which facilitate its use. The USEtox model is considering human toxicity for cancer and non-cancer effect in household (using phase) and occupational (production phase) level, further calculated by the total emission of the substance and its characterisation factor. The results obtained from the analysis of proposed H-House solutions show that the total cancer effect on human toxicity in household level is dominating the overall health impact. The results also show that cancer effect on human health is comparably higher than the non-cancer effect. However, several limitations have been identified when using the USEtox model that are related to data bias, modelling assumptions and lack of uncertainty calculation, and, most important, it has to be noted that the products currently evaluated in the H-House project are typically 10 times to 100 times below the regulatory limits for indoor emissions. Thus, the risk on human health coming from the materials proposed in H-House is negligible.
On a more general perspective, it should be mentioned that the impact assessment of building material on human health was done successfully in the project especially thanks to the close collaboration of material developers, laboratory measurements of actual emissions, and a research group establishing the link with Life Cycle Assessment methods. This collaboration makes possible to overpass all limitations linked to such studies. Nevertheless, the results also show that such an evaluation cannot be done yet as a routine calculation. Indeed, the complexity of existing models, the lack of data, and the need of better connection between risk assessment and impact assessment requires handling such a task as a research effort. More standardization is needed before a fast calculation of impact on human health is possible.
4 Demonstration
H-House prototypes are demonstrated on three locations. H-House partition walls based on stud construction was realised in an office building in Berlin, Germany. The owner explicitly appreciated the wood stud solution with earth boards and earth plaster to improve the indoor climate of the meeting room.
In Trino, Italy a mock-up was constructed with two UHPC-AAC elements with photocatalytic and super hydrophobic (self-cleaning) surfaces.
In Warsaw, Poland, two mock-up buildings were constructed. One demonstrator building is composed of TRC-FC sandwich and half-sandwich elements. The second building is composed of UHPC-AAC elements with photocatalytic and super hydrophobic (self-cleaning) surfaces. In both buildings, partition walls based on natural materials are incorporated. Moreover, the buildings will be used at least until August 2018 as exhibition rooms where H-House material samples are exposed to visitors.
Potential Impact:
The main dissemination activities included the creation and the maintenance of a project dedicated website, the publication of the project results in 4 peer reviewed scientific journals, on 14 international and 2 national conferences, 3 national symposia (3 lectures given at symposia after the end of the project), and several lectures at smaller national events. The project results were also presented at 3 national workshops (Sweden, Germany, Poland) and H-House material samples were exhibited at 4 international events (Architect@Work 2015 in Vienna, Austria; COM:BAU 2016 in Dornbirn, Austria; Building Material Congress 2016 in Stari Banovci, Serbia; BAU 2017 in Munich, Germany).
Most of the identified exploitable results and the knowledge obtained in the project will be directly used in industrial production or for research purposes. One result is exploited as a joint patent application.
List of Websites:
www.h-house-project.eu
katarina.malaga@ri.se
In recent years, significant efforts have been undertaken to reduce the CO2 emissions associated to the building sector. As the population increases, more buildings are required and thus more natural resources and energy are consumed during construction and operation. Coupled to the necessity to reduce the energy consumption, buildings are becoming heavily insulated and airtight leading to changes of the indoor environment. As people spend more and more time indoors, the occupant’s health, wellbeing and productivity is greatly affected.
The project H-House, ‘Healthier Life with Eco-innovative Components for Housing Constructions’, aimed to develop a number of multifunctional and flexible components for the building envelope and internal walls, for new buildings and renovation. Strongly focused on environmental aspects (such as reduced embodied energy and carbon footprint) and human comfort (thermal and acoustic), the main objectives were to increase the durability and energy-efficiency of materials and components and a healthier indoor environment by preventing the accumulation of pollutants and reducing noise.
Technical aims of the project were to develop lightweight façade elements based on Textile Reinforced Concrete (TRC) and Ultra-High Performance Concrete (UHPC). These elements have an integrated non-flammable insulation based on Foam Concrete (FC) containing aerogels and Autoclaved Aerated Concrete (AAC) optimized with regards to the use of natural resources and embodied energy. Application, of photocatalytic and hydrophobic surfaces contributes to the reduction of pollutants and prevention of harmful microbiological growth as well as towards easy-to-clean/self-cleaning facades. Indoor, the use of natural materials together with aerogels, improves temperature and moisture control as well and enhances reduction of the air pollution by absorption and photocatalytic decomposition of VOCs.
Project Context and Objectives:
1) Project context
The concept of H-House provides eco-innovative approaches on material level and on component level. The approach on the material level is to use existing knowledge and technology for further development of the physical properties concerning functionalization of surfaces, modification of water vapour permeability and moisture absorption capacity, reduction of moisture transport, increase of heat transfer resistance and reduction of embodied energy. The approach on the component level is to innovatively combine the developed materials to composite building elements for the building envelope and for internal walls / partitions, which are improved in functionality and in energy and acoustic efficiency, providing an improved indoor environment and easy disassembling for recycling.
The project consists of seven work packages (WP), where WP2 to WP5 are of technical and scientific content. WP2 is dedicated to material development, WP3 to the design and testing of building components. In WP4 the properties of the materials and the performance of the components is modelled and assessed towards the requirements. In WP5 the production technologies of the developed components are enhanced and prototype components are produced and exposed to the public. WP6 is entirely dedicated to life cycle assessment and the impact of the materials on human health. WP7 is dedicated to dissemination activities, market analysis and business plan.
2) Project objectives
The project concept addresses several objectives concerning the improvement of the indoor environment and the increased energy efficiency of building components:
a) To prevent accumulation of pollutants and harmful microbiological growth in the interior space by:
- use of building materials free of dangerous substances,
- photocatalytic decomposition and/or absorption of dangerous substances;
b) To improve moisture indoor control by:
- prevention of moisture ingress from exterior (building envelope),
- increase of moisture buffer capacity in the interior;
c) To improve thermal and noise protection of the indoor environment by:
- decrease of moisture flux into the building envelope and thus prevention of decreased insulation effect,
- use of acoustic damping effects of layered composites;
d) To develop and suggest new and efficient production technologies for low embodied energy building elements by:
- new light-weight sandwich panels for new buildings and half-sandwich panels for retrofitting with improved thermal and acoustic properties based on Textile Reinforced Concrete (TRC) with insulation of low density foamed concrete,
- new multifunctional façade elements with improved thermal and acoustic properties based on ‘green’ Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC) and low density foamed concrete,
- lightweight façade elements with improved thermal and acoustic properties based on hydrothermally produced (autoclaved) ‘green’ UHPFRC and Aerated Autoclaved Concrete (AAC) insulation material,
- new internal wall / partition systems based on earth, wood, wood fibre and cellulose;
e) To increase the durability and thus to decrease the maintenance costs of building envelops by
- activation of self-cleaning properties (application of photocatalytic material and/or micro-structural modification of surfaces in combination with hydrophilic / hydrophobic surface treatment),
- decrease of moisture flux into the building envelope due to densified micro-structure;
f) Implementation of the developed solutions in building components by:
- ensuring the effective transferability to precast and ready-mixed concrete companies across Europe,
- promotion of cost effective new materials or building components that are easy to produce and easy to assemble,
- designing at an early stage the recycle scenario, i.e. the separation of different materials after the use of the composite shall be possible without causing extraordinary expenses,
- introduction of life cost and life time estimation; this in turn requires that the material and building components can be described in a standardized way,
- contribution to standardization of the materials.
Project Results:
1 New Test methodologies
For the measurement of the materials’ emission and adsorption a special test chamber was designed. The advantage of test chamber is the possibility to use the complete bottom of the chamber to expose the material’s surface for emission/adsorption following international test standards. The special design allows for testing of single materials and composites consisting of several layers with a total thickness of up to approximately 15 cm, which makes it possible to investigate almost real scale building component setups.
Moreover, a simple screening test was used to estimate the materials’ VOC emissions in a relatively short time. The test is based on thermal extraction from the test samples. The gaseous extracts containing the analytes are collected on adsorbent tubes that are finally analysed using TDS-GC/MS. This test method could be used to quickly screen VOC emissions from construction wastes, e.g. volatile components of chemical concrete admixtures, which was identified as exploitable foreground.
2 Material development
2.1 Aerogel-modified Earth Plaster
Different types of aerogel and earth plaster have been investigated in order to select the most promising starting materials for the incorporation of aerogels in earth plasters to enhance the water vapour sorption activity. Resulting from preliminary application tests two types of hydrophilic aerogel (one powder with a maximum particle size of 100 µm and one granulate with a maximum particle size of 0.5 mm) and plant fibre reinforcement (to reduce drying shrinkage of the plaster) were proposed. The aerogel powder demonstrated a much better water vapour sorption activity than the granulated aerogel by means of sorption rate and total sorption capacity. On the other hand, the granulated aerogel is generally more convenient to work with since it is easier to pour and dusting is less pronounced. However, earth plasters modified with each type of aerogel showed similar water vapour sorption activities that were significantly improved compared to the pure earth plaster, i.e. the water vapour sorption was increased by 11-14% after 2 hours and 18-22% after 12 hours.
2.2 Textile-Reinforced Concrete (TRC)
The high-performance fine-grained concrete mix designed for TRC was further optimized and up-scaled according to the materials and equipment available for the prototype demonstrator production. The concrete mix of the TRC consists of a binder blend of CEM II/A-V 52.5 and fly ash and demonstrates acceptable frost resistance according to high Swedish requirements with a compressive strength of 109 MPa (at 28 d). The maximum aggregate size is 5 mm. The textile reinforcement that has been selected as the final solution for the TRC panels is a carbon textile grid. The selection was based primarily on the superior alkali resistance of the carbon material, which indicates promising long-term durability of the reinforcement in a concrete matrix. The flexural strength of the TRC is 7 MPa at first cracking and approximately 70 MPa at maximum load.
2.3 Ultra-High Performance Concrete (UHPC)
The UHPC developed in the project is based on the Nanodur technology. The boundary conditions for the development were set by a minimum compressive strength of the UHPC of 100 MPa, which was considered as sufficient for its use for the production of self-supporting composite facade elements. Reduction of embodied energy was achieved by replacement of Portland cement with supplementary cementitious materials (SCM). Currently the Portland cement content can be reduced to approximately 30 wt.-% of the binder, which is equivalent to 190 kg/m3 in the UHPC. Similar to Nanodur the two newly developed binder compositions are ready-to-use products and offered to the market as ‘TP H-House Compound GREY’ and ‘TP H-House Compound WHITE’.
The UHPC was used without fiber reinforcement that was abandoned in the course of the project because it did not improve significantly the mechanical performance of the UHPC in case of glass and carbon fibers. The use of steel fibers was neglected for aesthetical reasons (rust stains on UHPC surface).
In a series of tests the UHPC demonstrated acceptable durability performance with regard to its use in building envelope applications (high freeze-thaw resistance, very slow chloride migration, very slow carbonation).
2.4 Foam Concrete (FC)
An inorganic light-weight insulation material was developed based on foam concrete FC. For increased thermal performance the aerogel was incorporated. Additionally polymer fibres reduced the brittleness of the material. The material has the following properties:
- Density: 120-150 kg/m3
- Compressive strength: 100-300 kPa
- Thermal conductivity: 40-43 mW/(m K) without aerogel, 29-32 mW/(m K) with aerogel.
2.5 Autoclaved Aerated Concrete (AAC)
The development of AAC was based on the Multipor® technology (density: 115 kg/m3, thermal conductivity: 47 mW/(m K)) with regard to energy efficiency considerations. As the environmental impact of AAC production is dominated by the use of thermal energy and by the manufacture of the binders (cement and quicklime), emphasis was put on the replacement of energy-intensive Portland cement (CEM I) by alternative binders with lower embodied energy. Several blended cements were regarded as suitable for the manufacture of high-quality light-weight AAC from a mineralogical point of view and with regards to thermal performance. However, strength requirements were met only with Portland slag cement (CEM II/A-S 52.5 N) and blastfurnace cement (CEM III/A 42.5 N).
2.6 Self-cleaning surfaces
The surface of the materials for the building envelope, i.e. Textile Reinforced Concrete (TRC) and Ultra-high Performance Concrete (UHPC) forming the external shell (protective layer) of the new composite façade elements, was modified. Two approaches for surface modifications were followed to provide self-cleaning properties: photocatalytic activation and activation of the Lotus effect.
Photocatalytic activation was generally created using photoactive titanium dioxide (TiO2). For the TRC, TiO2 was either used as bulk additive to the concrete or as coating. A special form of application was the use of a TiO2 suspension distributed on the formwork before concrete cast. An optimum level of TiO2 addition into a fly ash based concrete has been established for both TiO2 products investigated at 4-8% weight replacement of cement. Variations of the reactivity at similar TiO2 dosage levels were due to different degrees of TiO2 dispersion in the concrete matrix.
The application of the TiO2 suspension on the hardened cement paste, i.e. as coating, resulted in a much higher photocatalytic activity than the bulk addition of TiO2. Also, the use of TiO2 dispersion directly on the formwork resulted in a very high photocatalytic activity. However, this method proved to aesthetically negatively affect the concrete surface.
The UHPC was photocatalytically activated by bulk addition of TiO2. It was demonstrated that moderate dosages, i.e. by addition of 1% TiO2 powder related to the total weight of solids (22 kg/m3), are sufficient to distinctly activate the photocatalytic self-cleaning effect. With these low dosages and the thin external layer of the UHPC composite facade elements the bulk addition of photoactive TiO2 might become also economically feasible. The durability of the photocatalytically activated self-cleaning was demonstrated by monitoring of UHPC samples subjected to outdoor weathering.
The second approach towards self-cleaning was to create a super hydrophobic UHPC surface. Super hydrophobicity is usually associated with contact angles of a water droplet ≥ 140-150°, which is often referred to as Lotus effect, and is the result of the coaction of a special micro texture of the surface and a chemical water repellence. Very good results were achieved by creating an adequate micro-structured UHPC surface through casting the UHPC on technical fabrics. In a later stage of the project, the micro structure was transferred to a rubber formliner, which was then used as the substrate for the UHPC and made repeated, and thus allowing more economic casts. The chemical water repellence was achieved by application of silane-based hydrophobic agents. It was demonstrated that the most efficient way to use the hydrophobic agent is its application on the micro-structured substrate before the concrete cast. This newly developed method was subject of a patent application. The durability of the super hydrophobic UHPC surface was demonstrated by artificial weathering tests and by monitoring of UHPC samples subjected to outdoor weathering.
3 Building components
3.1 Concept and Design
- Architectural design
An architectural design has been proposed based on a real case scenario in urban context for new construction application to present the possibilities of the developed sandwich facade elements and to highlight the boundaries of the systems including aesthetical aspects and constructional requirements like positioning of joints between elements and around openings joints, connectors and anchorage systems as well as a revised design regarding the dimensioning of the precast elements.
The development of floor layouts is taking into consideration an appropriate mix of different apartment sizes based on the definition of basic pattern suitable for optimization for most flexible floor plan layouts. Floor layouts have been designed as a case scenario that is mainly suitable for the development of council housing.
The design of the facade has been further extended with regards to structural details such as anchorage systems, connections and joints as well as a simplification of the panel typologies down to the basic dimensions of 3.6 m and 4.8 m panels in order to optimise its prefabrication ability. At the same time a wide range of different infill options (independent framework constructions) allow for the installation of numerous window typologies and facade applications to form an individualistic appearance of the building. Considerations with regards to maximisation of daylight have influenced the design proposals with a ratio to 38.5% at South façade and 22.3% to north facade to minimise heat losses in wintertime and solar gains in summer time.
- Partitions based on natural materials
The development of innovative solutions for eco-friendly, low carbon, low-emitting internal partition walls with high climate control capacities was finalised and guidelines for production technology of partition walls were prepared. A comprehensive number of wall designs, has been assessed and compiled in a matrix serving as a tool for comparison and evaluation. The matrix includes solid wall and stud wall constructions that might be used to create partitions located inside a flat as well as flat separation walls (mainly non loadbearing).
- TRC-FC composite facade elements
Two precast composite light-weight concrete facade elements are proposed, which incorporate TRC and FC:
1) Composite element consisting of two layers made of TRC for the external facing layer and FC for the insulation layer. The element is self-supporting and can be applied for refurbishment. The thickness of the insulation layer can be prescribed according to the desired thermal performance.
2) Composite element consisting of three layers made of TRC for the external facing layer and the internal load bearing layer and FC for the intermediate insulation layer. The element is load bearing and can be applied in new construction. The thickness of the facing TRC layer is 30 mm due to the element geometry and required embedment depth of the connectors.
The anticipated structural performance of the TRC-FC composite element was designated as a partially composite wall with load bearing internal TRC layer. Newly developed glass fibre reinforced polymer (GFRP) connectors were incorporated to provide a) a mechanical connection between the layers and b) a load transferring mechanism. Guidelines for the production technology of TRC-FC composite elements were prepared.
- UHPC-FC/AAC composite facade elements
A non-loadbearing box-shaped element made of an external UHPC shell was developed. The external shell protects and supports the insulation layer (FC or AAC). Guidelines for the production technology of UHPC-FC/AAC composite elements were prepared. The element configuration was implemented in order to optimise the hygrothermal behaviour of the elements following the different geographic/climatic scenarios assigned.
The box-shaped concept is a simple and robust solution for the facade elements. Besides the good structural performance, the concept enables efficient protection of the insulation material during transport, installation and use. Additionally, due to the absence of reinforcement and connectors through the insulation, the production technology does not involve major labour-intensive tasks, which is desirable for industrial production. A system of anchorage of the composite element was developed. The reliability of transport anchors and support anchors as well as the resistance of anchor rails to support window frames was assessed. The production technology of the element in two-step was implemented through a different selection of concrete material properties, including micro-structuring of the surface with rubber formliners.
Three alternatives of UHPC-insulation combinations were assessed. The use of FC and AAC blocks as insulation material proved to be reliable solutions, whereas the autoclaving of prefabricated UHPC/AAC-slurry elements showed detrimental effects on the quality of the UHPC surface (staining) and on the bond between UHPC and AAC.
3.2 Performance assessment
- Partitions based on natural materials
Based on numerous investigations on the material level, a comprehensive number of wall build-ups was assessed towards hygrothermal, structural and acoustic performance. It was demonstrated that earthen materials used either as plaster or as boards for dry walls bear high potential in improving the indoor environment quality because of their superior water vapour sorption activity, which is associated with an improved sorption of VOCs compared to conventional construction materials, such as gypsum. Moreover, in the case of stud wall constructions in was demonstrated that an adequate insulation material, e.g. wood fibre mats, can contribute significantly to a favourable hygrothermal activity of the partition wall.
The structural integrity was proved for a variety of eco-innovative solutions, such as earth and wood fibre boards for stud constructions and flax or straw panels for solid walls. In some cases, a lack of sufficient resistance against light console loads was observed with very light-weight earth and wood fibre boards. However, this disadvantage can be compensated by connecting consoles directly to the studs of the wall.
The assessment of the sound insulation properties revealed that 9 out of 28 tested partition wall build-ups cannot be used as separations between dwellings. However, this assessment was based on small-scale acoustic tests, which is restraining the validity of the assessment.
- Composite facade elements
TRC-FC and UHPC-AAC/FC composite elements have been assessed concerning their load-bearing capacity under the action of self-weight and wind load. With the help of numerical modelling of the full scale composite elements, ultimate limit state loads have been determined for bending and shear failure, which were subsequently verified in lab-scale experimental investigations. The experimental results showed that the actual load-bearing performance of the elements is well above the required load-bearing capacity. The experimental results confirmed also that the proposed solutions for transport anchors and anchorage for windows/doors, to be cast in the UHPC elements, are able to carry the design load assigned.
The assessment of the hygrothermal performance of the façade elements, which was based on experimentally obtained material characteristics and numerical modelling, revealed that the current design of the proposed solutions meets well the requirements regarding thermal transmittance (thermal bridges considered):
- UHPC-AAC element: U = 0.14 W/(m2 K), thickness of insulation: 350 mm
- UHPC-FC element: U = 0.11 W/(m2 K), thickness of insulation: 350 mm
- TRC-FC sandwich element: U = 0.26 W/(m2 K), thickness of insulation: 150 mm.
The numerical analysis of the moisture and heat flow through the facade elements showed that the risk of moisture condensation inside the elements is very low, even though thermal bridges were detected, which are inevitable due to the edges of the UHPC box design and the connectors in the TRC element.
The assessment of the acoustic performance showed that a joint between two elements is significantly affecting the sound insulation. Nevertheless, all types of H-House facade elements show a very good performance with sound insulation values well above the limit of the highest sound insulation class according to European recommendations. The comparison to German and Polish requirements revealed medium to high sound insulation performance of all types of the H-House facade elements tested.
Experimental tests according to European protocol confirmed the durability of the proposed H-House solutions for the building envelope.
3.3 Life Cycle Assessment and Life Cycle Cost Analysis
The Life Cycle Assessment (LCA) in the frame of the H-House project was an iterative process, starting with a global scope definition and the establishment of a methodological framework. In a second step, Life Cycle Inventories (LCI) were created and continuously updated according to the actual state of the art concerning design and material properties. Finally, a selection of innovative building components developed during the H-House project has been studied regarding their life cycle performance:
- TRC-FC sandwich facade element with photocatalytic properties
- UHPC-AAC facade element with photocatalytic properties
- UHPC-FC facade element with super-hydrophobic properties
- Partition wall based on natural materials (wood fibre board on timber stud construction with internal wood fibre insulation and earth plaster rendering).
Several comparative studies have been conducted on both environmental life cycle impacts (i.e. through LCA) and global costs (i.e. through LCC) taking into account different conventional scenarios, location of use and service life. The life cycle impact assessments were performed for seven categories: non-renewable energy, climate change, acidification, terrestrial eutrophication, freshwater eutrophication, freshwater ecotoxicity and land use. Non-renewable energy and climate change were considered as the most important impacts and in most cases, similar trends were observed for both indicators.
The LCA has been performed for facade elements of the same U-value. In contrast, the LCC of the H-House solutions were compared to the LCC of the reference walls having a lower thermal performance matching with what is commonly installed nowadays in the location considered. As a consequence, an additional consumption for the heating of the building is accounted for in the conventional scenario. In case of the partition wall conventional gypsum plasterboard dry lining wall was taken into account as reference scenario.
The TRC-FC sandwich element was compared to a conventional reinforced concrete sandwich element with EPS insulation and to a cast-on-site reinforced concrete wall with rock wool insulation. The most important observation is that the higher environmental impact of the innovative TRC-FC sandwich element in the production stage is compensated by its lightweight contributing in reducing substantially the impact of its transport and installation as well as its end of life treatment. Moreover, the aerogel has a major influence on the environmental impact of the FC that is higher than the ones of EPS and rock wool. When the FC is produced without aerogel its environmental impact is lower than EPS. The costs for production and installation of the innovative TRC-FC sandwich element are, due to the novelty of the proposed production technology, higher than for the conventional reference scenarios where the production lines are well established. But, taking into account realistic assumptions on the real discount rate and the growth rate of energy price the lower heating costs can compensate the investment costs with lower global costs at the end of lifetime (after 50 years) compared to both reference scenarios.
The UHPC-AAC and the UHPC-FC elements were compared to a conventional reinforced concrete cladding with rock wool insulation. In both cases the environmental impact of the innovative UHPC element is higher than the conventional concrete solution. Moreover, the global costs of both innovative UHPC element variations are superior to the one of the conventional cladding scenario, whatever the real discount rate and growth rate of energy price are, among plausible values. This means that the investment costs of the innovative UHPC elements are so high that they cannot be compensated by lower costs for heating.
However, it has to be pointed out that (i) different sources were used to create the cost inventories, which might introduce a bias in the assessment, and (ii) the cost inventories are based on conservative assumptions, i.e. the production and installation costs of the innovative light-weight facade elements have been assumed rather high in comparison to the conventional solutions. Moreover, the higher durability of the UHPC in comparison to the conventional concrete was not considered in the LCA/LCC. Due to the lack of reliable data in both innovative solution scenario and conventional reference scenario the same lifetime was assumed without any repair of the conventional concrete. Superior performance (self-cleaning) was considered with lower or no costs for cleaning compared to the conventional solutions, but again, due to the lack of database rather low costs for the cleaning of the conventional concrete have been assumed.
3.4 Impact on Human Health
The human impact from indoor toxic pollutants was evaluated based on measured emission rates of the construction materials and the characterisation factors of the substances emitted from the samples. The impact was calculated for carcinogenic and non-carcinogenic substances, and for household and occupational scenarios. Thus, it was possible to complete all the objectives concerning impacts assessment on human health. Nevertheless, beyond practical results, strong emphasis was done to cover methodological aspects. Therefore, the studies performed in the frame of H-House enable to address in detail critical questions and to bring new insight for applying LCA of building products including impact assessment on human health.
The most relevant model to assess impact on human health in LCA for indoor emissions is the USEtox model. It is a consensual model, largely used in LCA, with an extended database of characterisation factors which facilitate its use. The USEtox model is considering human toxicity for cancer and non-cancer effect in household (using phase) and occupational (production phase) level, further calculated by the total emission of the substance and its characterisation factor. The results obtained from the analysis of proposed H-House solutions show that the total cancer effect on human toxicity in household level is dominating the overall health impact. The results also show that cancer effect on human health is comparably higher than the non-cancer effect. However, several limitations have been identified when using the USEtox model that are related to data bias, modelling assumptions and lack of uncertainty calculation, and, most important, it has to be noted that the products currently evaluated in the H-House project are typically 10 times to 100 times below the regulatory limits for indoor emissions. Thus, the risk on human health coming from the materials proposed in H-House is negligible.
On a more general perspective, it should be mentioned that the impact assessment of building material on human health was done successfully in the project especially thanks to the close collaboration of material developers, laboratory measurements of actual emissions, and a research group establishing the link with Life Cycle Assessment methods. This collaboration makes possible to overpass all limitations linked to such studies. Nevertheless, the results also show that such an evaluation cannot be done yet as a routine calculation. Indeed, the complexity of existing models, the lack of data, and the need of better connection between risk assessment and impact assessment requires handling such a task as a research effort. More standardization is needed before a fast calculation of impact on human health is possible.
4 Demonstration
H-House prototypes are demonstrated on three locations. H-House partition walls based on stud construction was realised in an office building in Berlin, Germany. The owner explicitly appreciated the wood stud solution with earth boards and earth plaster to improve the indoor climate of the meeting room.
In Trino, Italy a mock-up was constructed with two UHPC-AAC elements with photocatalytic and super hydrophobic (self-cleaning) surfaces.
In Warsaw, Poland, two mock-up buildings were constructed. One demonstrator building is composed of TRC-FC sandwich and half-sandwich elements. The second building is composed of UHPC-AAC elements with photocatalytic and super hydrophobic (self-cleaning) surfaces. In both buildings, partition walls based on natural materials are incorporated. Moreover, the buildings will be used at least until August 2018 as exhibition rooms where H-House material samples are exposed to visitors.
Potential Impact:
The main dissemination activities included the creation and the maintenance of a project dedicated website, the publication of the project results in 4 peer reviewed scientific journals, on 14 international and 2 national conferences, 3 national symposia (3 lectures given at symposia after the end of the project), and several lectures at smaller national events. The project results were also presented at 3 national workshops (Sweden, Germany, Poland) and H-House material samples were exhibited at 4 international events (Architect@Work 2015 in Vienna, Austria; COM:BAU 2016 in Dornbirn, Austria; Building Material Congress 2016 in Stari Banovci, Serbia; BAU 2017 in Munich, Germany).
Most of the identified exploitable results and the knowledge obtained in the project will be directly used in industrial production or for research purposes. One result is exploited as a joint patent application.
List of Websites:
www.h-house-project.eu
katarina.malaga@ri.se