Greengauge Directors Toby Cambray and Hannah Jones share their thoughts on the tension between fabric retrofit (demand reduction) and heat pumpification (decarbonisation) when retrofitting heritage buildings.
Decarbonising heritage buildings present unique challenges in the need to balance supply decarbonisation and demand reduction, whilst also preserving the character of older buildings.
Heritage buildings
The variety of older buildings in the UK and different construction materials and methods used, present additional challenges for decarbonisation.
With heritage buildings, planning and listed building constraints are often an additional considerations when planning decarbonisation strategies for heritage buildings.
Heat pumps
Heat pumps can be an ideal heating source for heritage projects and work efficiently if supply temperatures are kept low. There can be potential challenges of installing large heating emitters in heritage buildings, which may require careful planning to avoid damaging historic fabric.
Fabric retrofit
Although heat pumps offer an excellent ‘quick win’ for decarbonisation, fabric retrofit is still very important for heritage buildings to reduce energy demand and improve the efficiency of heat pumps.
As well as reducing pressure on the grid and overall energy demand, fabric retrofit offers other co-benefits such as resilience, reduced moisture risks, improved durability and performance, and improved summer comfort.
Flexibility
There need to be flexible policy approaches to retrofit, allowing for tailored solutions that meet the specific needs of individual buildings.
Case studies
- The Barrel Store certified EnerPHit was a fabric first heritage retrofit that achieved a 75% reduction in space heating. The project involved an internal wall insulation (IWI) strategy. The building is now ready for future heat pump installation.
- The retrofit of a Tudor Manor in the Cotswolds, focused on heat pump installation and on adapting the existing heating system to run at lower temperatures
- A hybrid approach was employed for a house in Bath, combining fabric improvements and heat pump installation. Collaboration with conservation authorities was crucial to the project’s success, ensuring that the retrofit respected the building’s heritage while improving its energy performance.
