Pros And Cons Of Fabric-First Net Zero Carbon Retrofits
There are several different methodologies for net zero carbon retrofits. There is the ‘whole house’ approach which views a house as an energy system with interconnected parts. There’s also an ‘insulate and then generate’ philosophy that upgrades the insulation and aims to meet the energy deficit by installing renewable energy systems.
Related to this is the fabric-first approach.; This involves analysing the structure of a house and fitting the most effective (and cost-effective) treatments to improve thermal insulation and airtightness. Energy efficiency measures are then applied to systems for heating, lighting and cooking. Finally, renewable energy generation is installed to balance any carbon deficit.
In practice, there are similarities between each methodology. Given that the fundamental objective is to reduce energy use, fabric-first seems the appropriate place to start.
Insulation and Airtightness
Most of the UK’s housing stock would benefit significantly from upgraded insulation of walls, floors and roofs. Improved airtightness – particularly at openings and interfaces – would also make many homes significantly cheaper to heat. Many homes also have thermal bridges that transmit heat from inside to outside.
The initial survey will identify which treatments are feasible and cost-effective to improve the thermal efficiency of the home.
Fabric-First Net Zero Limitations
This, however, isn’t the end of the story. You can’t make a house airtight without considering ventilation. Otherwise you risk creating poor air quality and damp. This is where whole house considerations come into play to avoid unintended consequences.
Fabric-first may also overlook planning constraints (such as conservation areas) and the aesthetic impact of the retrofit. Upgrade programmes that alter the appearance of a street or district may not be acceptable.
Dealing with the fabric to make a home better insulated and more airtight is the foundation of any net zero carbon retrofit. It isn’t, however, the whole solution and other considerations are needed to guarantee a successful outcome. This is why detailed analysis and careful planning are at the heart of every Osborne retrofit programme.