Smart retrofitting of older buildings
Architects and engineers work with the latest standards and materials in order to reduce heat loss in new buildings. However, making older stock more energy efficient is a greater challenge, often requiring the retrofitting of insulation materials both inside and out. In addition, many older buildings have preservation orders to protect them from significant alterations. The EASEE (Envelope Approach to improve Sustainability and Energy efficiency in Existing multi-storey multi-owner residential buildings) project is tackling these issues by developing different types of advanced insulating components and materials for the three main envelope parts – the outer façade, cavity walls and interiors. The project has also designed a new consulting software tool for the building sector called the Retrofitting Planner. For the outer façade, the project team has developed prefabricated insulating panels, which are made of textile reinforced mortar (TRM) with a core of polystyrene foam. The panels are hung from a building’s exterior using special devices made of Ultra High Performance Fibre Reinforced Concrete (UHPRFC). The panels can be produced in different sizes, thicknesses and forms, allowing for tailored retrofitting to a variety of buildings. Plus, the installation method does away with the need for scaffolding. As part of the assessment process, 40 panels were manufactured and installed at a residential building in Poland. The insulation value of the panels is expected to be 60 % greater than the base wall. Full-scale testing of this product is now underway on a three-floor building in Milan which contains 6 apartments. The design will use 186 panels with different colours and textures. The building envelope has been mapped using 3D laser scanning techniques to provide a high degree of accuracy and detail. The Retrofitting Planner was used to evaluate cost, performance and return on investment. For the cavity walls, the project has developed a water-repelling process for both natural and synthetic expanded perlite. The insulating materials have been tested in the cavity walls of the Milan façade and reveal an 89 % improvement in heat retention. In addition, the synthetic perlite was developed using mineral waste, recycled materials and industrial by-products. The main advantage of this product is that its formulation can be altered in order to meet different requirements. EASEE has delivered three kits for interior retrofitting, all of which have been prototyped and installed at the Milan site. A light-weight perlite insulating board comes complete with a dedicated adhesive mortar and a thin layer of finishing render. This innovation offers improved thermal performance compared to existing, similar products. A permeable insulating wall-paper has been produced by impregnating a textile product made of non-woven polyester fibres and aerogel. The lightweight wall-paper is thin and easy to roll – and can be handled by one or two people. Finally, a flat laminated board has been created using an aerogel and textile insulating layer which delivers improved thermal performance. Project coordinator, Andrea Ferrari, said: ‘What we have aimed for in our work is to offer flexible solutions to improve the energy performance of older buildings – especially those constructed before the 1970s – which often cannot be altered with invasive construction work. Our innovations can be used together or separately depending on the building in question. What is more, the installation of EASEE products can be achieved with minimal disruption to residents – as our Milan test-bed is proving.’
Keywords
EASEE, insulation, wall-paper, residential buildings, perlite, façade, energy efficiency
