What a warm roof is
The old glass or polycarbonate panels come off. A lightweight roof frame goes on the existing conservatory. It is insulated, covered with a breathable membrane, battened and finished with lightweight tiles.
Inside, plasterboard is fitted and skimmed, so the ceiling looks like any other room in the house. You keep the walls, frames and floor you already have.
Why conservatories get so cold and so hot
Glass and polycarbonate let heat straight through. In winter the warmth from your radiators escapes through the roof. In summer the sun turns the room into a greenhouse.
An insulated roof deals with the cause. It keeps heat in during winter and blocks the worst of the sun in summer. It is also quieter in heavy rain.
Why building regulations apply
Many conservatories are exempt from building regulations. The Planning Portal says this is normally the case when the conservatory is at ground level, single storey and under 30 square metres. It must also be separated from the house by external quality walls, doors or windows, with its own heating controls.
Putting on a solid roof changes things. The roof is heavier, so the frames and base must carry the load. The room holds heat differently, so the energy rules in Part L come into play. The Planning Portal says a new roof must comply with building regulations so it is structurally safe, energy efficient and properly ventilated.
In practice this means the work should be checked and signed off. Ask your installer who will deal with building control, and ask for the paperwork when the job is done.
| Glazed conservatory (exempt) | Warm roof conversion | |
|---|---|---|
| Roof | Glass or polycarbonate | Solid, insulated, tiled roof with a plastered ceiling |
| Building regulations | Normally exempt if it meets the Planning Portal conditions | A new roof must comply with building regulations |
| Weight on frames and base | Light | Heavier, so the structure must be checked |
| Heat in winter | Escapes through the roof | Held in by insulation |
| Planning permission | Often not needed | Usually permitted development, but check if the roof changes a lot |
Do I need planning permission too?
Usually not. The Planning Portal says most alterations to roofs count as permitted development, as long as they meet the limits in the law. If the change significantly alters the structure or look of the roof, planning permission may be needed.
If your home is listed or in a conservation area, check with your council before any work starts.
Questions to ask before you agree a warm roof
Get clear answers to these, ideally in writing:
- Who will arrange building control sign-off, and will I get a certificate?
- Have you checked that my base and frames can carry a solid roof?
- Which roof system do you use, and has it been reviewed by building control?
- Who does the plastering inside?
- Is new guttering included?
The roof system we use
Our warm roofs use the Tectorum lightweight tiled roof system. MFA Building Control has reviewed the Tectorum pitched solid roof and flat roof systems and confirmed that they meet the Building Regulations. We explain what applies to your home at the survey, before any work is agreed.
Sources
General facts on this page come from these official sources. Rules can change, so check the latest version before you rely on them.
- Planning Portal: Conservatories, building regulations (opens in a new tab)
- Planning Portal FAQ: Do I need building regulations approval or planning permission to change the roof on my conservatory? (opens in a new tab)
- legislation.gov.uk: The Building Regulations 2010, Schedule 2 (exempt buildings and work), Class 7 (opens in a new tab)
- GOV.UK: Conservation of fuel and power, Approved Document L (opens in a new tab)
- GOV.UK: Structure, Approved Document A (opens in a new tab)
- GOV.UK: Building regulations approval (opens in a new tab)