Treated Floor Area
LETI Climate emergency retrofit guide, How existing homes can be adapted to meet UK climate targets, published by LETI in October 2021, defines Treated Floor Area (TFA) as: 'The internal area of a dwelling less the footprint of internal walls and other uninhabitable spaces. Measured on all habitable floors. Typically this is around 90% of the Gross Internal Area.’
[edit] Related articles on Designing Buildings
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
Recognition, influence and growth
SocEnv identifies three strategic pillars in new strategy to 2045.
Discover the future of roofing, cladding and insulation.
New guidance for professional practice, cultural change and regulation in social housing.
The heritage of nuclear and conventional power stations.
New measures to stop people being ripped off
Government to protect families from cowboy builders and aggressive bailiffs.
New Futurebuild showcase brings an innovation-first approach.
National Planning Policy Framework
Understanding the 2026 changes.
ECA's public affairs priorities
Member consultation opens to shape priorities for 2027 to 2030.
Dutyholder responsibilities from 1 July 2026.
Where performance meets practice
The Building Envelope Stage at UKCW Birmingham.
CIAT publishes briefing on planning reforms.
Leaders in Learning for Practice Network
Call for conservation leaders in learning to register interest in new network.

















