The Old House, Boxley project has been awarded the Conservation and Historic (up to £20 million) category at the Architects’ Retrofit Award.

Conker joined the team of experts 7 years ago to provide advice on insulation options for the historic thermal envelope, U value calculations and condensation risk assessment. The client, the Society for the Protection of Ancient Buildings, also created a volunteer programme to allow hands-on training in traditional techniques for conservation professionals, architects, surveyors and craftspeople.

The judges said the project represents “as real exemplar of different techniques that be employed to bring a building back to life” and it was an “amazing job…putting together a building that was on its last legs”.

Air leakage was tested before commencement at 22.25 air changes per hour; this was reduced to 9.29, still relatively poor but a fair result for such a complex building.

Energy consumption was estimated using PHPP at 601 kWh/m2a (40x worse than Passivhaus!) and the worst building we have ever evaluated. This was reduced to 35 kWh/m2a, a 42% reduction and still the worst figures we have ever calculated. However, due tot he architectural and archaeological limitations, a good result.

The building uses an air sourced heat pump to provide a constant low level of heating. Professor Bill Borders has spent time fine tuning the system for maximum efficiency. A report on this will follow from the SPAB. A more detailed review will appear on our Project Pages soon.

You can read more about the award and the project at: https://www.spab.org.uk/news/st-andrews-chapel-wins-architects-journal-retrofit-award