Responsible retrofit: making old buildings liveable without costing the earth

18 February 2014

An exciting collaboration at UCL, part of the Knowledge Transfer Partnership (KTP) scheme, is breathing new life into old buildings – without costing the world.

construction site

Updating historic houses

The UK is facing a housing crisis, with demand far outstripping supply. One attractive alternative to new-builds is the revival of older buildings, restoring historic structures to full functionality. But retrofitting presents a host of challenges. How do you make draughty old buildings energy-efficient, damp-free and wellventilated, whilst minimising your impact on the environment?

It’s an issue that sustainable building supplier Natural Building Technologies (NBT) can now take on, thanks to a recent partnership with UCL.

Neil May, Managing Director at NBT explained, “We provide high-performance building solutions for private and public housing organisations. Our products include environmentally sound structural building systems for walls, roofs and floors, as well as ranges of ecological paints, mineral plasters and renders, and natural fibre insulation.”

New ways to warm walls

Heat loss is a major issue with older buildings, many of which were built long before we worried about our carbon footprint. Whilst insulation is a vital part of any retrofit, it’s not just the thermal effect of insulation that matters. Neil said “The moisture performance of materials is crucial for preventing damp. So we were very keen to explore novel, natural breathable materials to develop effective, sustainable insulation.”

Seeking expertise in buildings physics, NBT paired up with UCL’s Valentina Marincioni (Bartlett School of Graduate Studies), Research Associate, who has an MEng in Thermal Mechanics. She explained, “Our two-year project examined the performance of solid-wall traditional buildings insulated internally with breathable and non-breathable insulations. I used modelling, laboratory testing and case studies – and the results have been extremely useful.”

All-round results

The project provided interesting findings on the accuracy of modelling, the moisture performance of different kinds of insulation, and the importance of location and wall orientation. These results have already fed into the design of a new composite insulation board by NBT – a fantastic development for the business. Neil said, “We’re delighted with the progress we’ve made. We are now one of very few organisations to have secured a 25-year warranty for internal wall insulation, putting NBT in a leading market position.”

For Valentina, the experience has been a career boost: thanks to the partnership, she is now one of the leading UK experts in retrofit. She has published an academic paper together with her academic supervisor, Dr Hector Altamirano-Medina (Bartlett School of Graduate Studies), Lecturer in Environmental Design and Engineering at UCL, who provided support in experimental design and analysis.

Valentina commented, “I’m pleased with the outcomes of the partnership, for myself and my academic department – as  well as for NBT and for the impact on sustainable retrofit in future. Working in an industrial setting gave me a great insight into the real-world requirements for retrofit building materials.”

The Natural Building Technologies KTP has been judged as outstanding by the Technology Strategy Board – an achievement only awarded to 5% of KTP projects.

A collaborative future

The collaboration between UCL and NBT continues as Valentina has been co- sponsored by the company and EPSRC to undertake an Engineering Doctorate based on developing a holistic approach to moisture management for retrofit. Neil May has been seconded into UCL’s Complex Built Environment Systems Research Group, a multidisciplinary team across Bartlett School of Graduate Studies and UCL Energy Institute focused on developing solutions to the practical problems of designing, constructing, and managing environments within and around buildings.

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