Warm roof
On flat roofs, a 'warm roof' is one in which the insulation layer is laid on top of roof structure. This results in the structural deck and its supports being at a temperature closer to that of the building’s interior. This is as opposed to a 'cold roof' in which the insulation is below, or within the roof structure, and so the roof structure is closer to the outside temperature.
An 'inverted roof' is a form of warm roof in which the waterproofing layer is beneath the thermal insulation rather than above it.
On pitched roofs, the definition of warm or cold can relate to the entire space below the pitch of the roof, but above the ceiling. This means that a warm roof might be one in which the insulation is installed in line with the rafters (rather than above the roof structure), so that the space under the pitch, ie a loft, attic or other space is insulated and warm. A cold roof in this case would typically have insulation laid above the ceiling so that the loft space below the pitched roof is cold relative to the rest of the property.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Design and construction industry podcasts
Professional development, practice, the pandemic, platforms and podcasts. Have we missed anything?
C20 Society; Buildings at Risk List 2025
10 more buildings published with updates on the past decade of buildings featured.
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation, closing 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.