A replacement conservatory roof means removing the old roof, usually polycarbonate or early glass, and fitting a new glass, solid tiled or hybrid roof onto the existing frames and base. If the base, dwarf walls and frames are sound, it is often the most cost-effective way to turn an uncomfortable conservatory into a room you use every day. Published UK market guides put a typical replacement anywhere from a few thousand pounds to over £15,000, depending on size and roof type, and most installations take between one and five days on site. This page covers whether your conservatory is a good candidate, the structural survey, Building Regulations, market cost guides and timescales. For a general introduction to conservatories, see our conservatories page.
Is your conservatory a good candidate?
A new roof is worth considering if the room is unusable in summer or winter, the polycarbonate has yellowed or leaks, rain noise drowns out conversation, or the glazing bars and seals are failing. It is a worse bet if the base has moved. Signs of that include cracked dwarf walls, doors that have dropped or will not close, a gap opening up where the conservatory meets the house, or a floor that slopes away. In those cases, the foundations need investigating first, and sometimes a full rebuild is better value than a new roof on a moving structure.
Your options
- Like-for-like polycarbonate. The cheapest route and quick to fit, but it does little for comfort or noise.
- Glass. Modern coated glass keeps the light while cutting overheating and heat loss. See glass roof conservatories for the glass types.
- Solid tiled. An insulated roof with a plastered ceiling makes the room feel like part of the house. See solid roof conservatories.
- Hybrid. A solid roof with glazed panels or a roof lantern keeps some daylight over the area where you want it.
The structural survey
Every replacement starts with a survey of what the new roof will sit on. LABC’s guidance on solid conservatory roofs sets out the main checks, which are useful for any heavier roof:
- Frame reinforcement. Frames built for polycarbonate may only be reinforced for that light load. Reinforcement can be confirmed by drilling pilot holes or testing with a magnet for a steel core.
- Door supports. Door frames should carry roof loads to the floor slab, usually through steel inserts.
- Foundations. Trial holes may be dug to confirm the foundations. LABC notes a 150mm concrete strip or reinforced slab on original ground is usually adequate, but drains, nearby trees and filled ground need more thought. Our page on conservatory bases explains why.
- The house wall. We check where the new roof will meet the house for flashing, first-floor windows, gutters and soil pipes.
Building Regulations and planning
Building control guidance, such as North Norfolk’s, defines a conservatory as having a roof at least 75% translucent and walls at least 50% translucent. Replacing polycarbonate with glass keeps that character, so an otherwise exempt conservatory generally stays exempt, although the glazing must still comply. Replacing it with a solid or largely solid roof takes the room outside the exemption, and the new roof must meet current standards for structure, insulation and weatherproofing. LABC has also said, in answers to homeowners, that insulating an existing polycarbonate roof needs approval too. We tell you at survey which route applies and handle the building control submission as part of the project.
Replacing a roof without enlarging the conservatory does not usually need planning permission, but check with your council if your home is listed, in a conservation area or has had permitted development rights removed.
What does a replacement conservatory roof cost?
We price every roof after a survey. To help you budget, here is what published UK cost guides say. These are market guides gathered by third parties, not our prices.
Checkatrade (updated March 2026)
Checkatrade’s conservatory roof replacement guide gives average costs by size and roof type:
- 3m x 3.5m: polycarbonate £6,300, tiled £7,875, glass £9,450;
- 4m x 4m: polycarbonate £9,600, tiled £12,000, glass £14,400;
- 4.5m x 4.5m: polycarbonate £12,150, tiled £15,188, glass £18,225.
Per square metre, it quotes £400 to £800 for polycarbonate, £600 to £1,200 for glass and £600 to £900 for tiles.
MyJobQuote (updated October 2026)
MyJobQuote’s guide gives much lower figures for a medium 4m x 4m roof: £2,700 to £4,000 for polycarbonate, £3,200 to £4,800 for glass and £5,000 to £6,800 for solid tiled, with a typical overall range of £3,200 to £6,000.
The Eco Experts (updated March 2025)
The Eco Experts puts a standard solid roof replacement at £7,000 to £20,000, and reminds readers to budget for plastering the interior.
The gap between these guides is large, mainly because they include different things. When comparing quotes, check whether each covers removal and disposal of the old roof, any frame reinforcement, internal plastering and decoration, electrics and lighting, guttering, building control fees and making good where the roof meets the house.
How long does it take?
Checkatrade says most roof replacements take two to five days. MyJobQuote suggests one day for a small polycarbonate roof and adds one to two extra days for a solid or tiled roof compared with glass or polycarbonate. Plastered ceilings then need time to dry before decoration. Before work starts, allow time for the survey, design, any building control application and manufacture of the roof. If you are replacing the side frames as well, our aluminium windows have a lead time from 10 days.
What happens on site
- We protect the floor and furnishings, and the room is cleared.
- The old roof is stripped and taken away, with the room kept weathertight overnight.
- Any reinforcement to frames or posts is fitted.
- The new roof structure goes on, followed by glazing or insulation, membrane and tiles.
- Flashings, gutters and downpipes are completed.
- For a solid roof, plasterboard and skim go on inside, and lighting is fitted and certified.
- Building control inspects where required, and we walk you through the finished room.
Upgrade the rest while you are at it
Once the roof is fixed, draughty side frames and tired doors become the weak point. Replacing them with aluminium or UPVC frames, or swapping old doors for French doors or bifolds, is easier now than after decorating. Roof blinds are best measured once the new roof is in.
Mistakes to avoid
- Choosing on price per square metre without checking what is included.
- Fitting a heavy roof without confirming frame reinforcement and foundations.
- Skipping building control for a solid roof, which can cause problems when you sell.
- Going fully solid on a north-facing room that lights the kitchen, then finding the house darker.
Book a roof survey
We survey and replace conservatory roofs across Windsor, Maidenhead, Berkshire, Buckinghamshire, Surrey, west Kent and north West Sussex. Call 01753 965 005 or request a free quote, and we will check your frames and base and explain the options honestly.
Frequently asked questions
How much does a replacement conservatory roof cost?
Published guides vary widely. Checkatrade, updated March 2026, gives averages for a 4m x 4m roof of £9,600 for polycarbonate, £12,000 tiled and £14,400 glass, while MyJobQuote quotes far lower figures. They include different items, so these are market guides only. We price each roof after surveying the frames and base.
How long does it take to replace a conservatory roof?
Checkatrade says most replacements take two to five days on site, and MyJobQuote notes that solid tiled roofs take one to two days longer than glass or polycarbonate. Plastered ceilings need drying time before decorating. Before that, allow time for the survey, design, any building control application and manufacture of the new roof.
Do I need Building Regulations approval to replace my conservatory roof?
It depends on the new roof. Replacing polycarbonate with glass generally keeps an exempt conservatory exempt, provided the glazing complies. A solid or largely solid roof takes it outside the exemption because a conservatory needs a mostly translucent roof, so the new roof must be approved by building control. We confirm which applies at survey.
Can my existing frames support a new roof?
Often, but it must be checked. Frames built for polycarbonate may only be reinforced for that light load, so a heavier glass or tiled roof can need extra reinforcement or posts. LABC suggests checking for steel cores with pilot holes or a magnet, and trial holes for the foundations if the load increases.
Is it worth replacing the roof rather than the whole conservatory?
If the base, dwarf walls and frames are sound, usually yes, because the roof causes most comfort problems. If there are signs of movement, such as cracked walls, sticking doors or a gap at the house wall, the foundations need investigating first and a rebuild may be better value than a new roof.