Grosvenor Estate cottages, Cheshire: a benchmark project for heritage retrofit, a project case study with signatory Donald Insalls Associates.
The climate emergency demands that the UK and other major economies make a very rapid transition to net zero carbon emissions. Improving the energy performance of Britain’s existing housing infrastructure is a crucial step towards that goal. The Government’s declared aim is to get all British homes up to Energy Performance Certificate (EPC) Band C by 2035. With less than 30% currently at the target level, that’s a tall order; and many doubt whether it can be met without devastating effects on the significance of the nation’s historic housing stock.
This benchmark project by Heritage Declares signatories Donald Insall Associates, in collaboration with major landowners The Grosvenor Estate, will help to provide an objective answer to these questions. A Grosvenor-owned property on a rural estate in Cheshire, comprising a pair of red-brick semi-detached cottages built in 1896, is being used as the test-bed for a ‘whole house’ approach to sustainability-led retrofit – one that takes into account not just building fabric but also services and occupant behaviour, and that gives due weight to embodied energy and the environmental costs of manufacture, transport and waste.
A preliminary desktop research phase having been completed, the project team are now conducting air pressure tests and thermal imaging scans to determine how the building performs in its unaltered state. A variety of heating and insulation strategies will then be tested and assessed. The aim is to develop a viable and repeatable best-practice approach to retrofit that adds value in terms of reduced energy bills, and that can be implemented by Estate staff without the need for specialist consultants. A design guide for similar projects will also be prepared, along with a ‘user manual’ for tenants. Insalls hope that the results of the study will ‘challenge the current assumption that traditional buildings will always have a low value EPC’, and will thus help address ‘a clear danger to the viability of historic buildings’.