New roof or a whole new conservatory?

When a conservatory is leaking, too hot in summer and freezing in winter, it can seem simpler to pull it down and start again. Often it is not. In most conservatories the frames, dwarf walls and base are fine, and the roof is the problem. A new roof costs less, takes days rather than weeks and leaves the rest of the house largely undisturbed.

There are real cases for starting again, though, and one trap to avoid: a brand new conservatory with a glass roof can be just as uncomfortable as the old one. What makes a conservatory usable all year is mainly the roof, not the age of the walls.

New roof vs new conservatory at a glance

	New tiled roof	New glass roof	Whole new conservatory
Price, medium conservatory (about 4m x 3.5m)	£7,400 to £12,100 (typically about £9,600)	£3,500 to £7,000 (typically about £5,200)	From about £8,000; £15,000 to £30,000 in one 2024 guide; varies widely
Roof heat lost (U-value, W/m²K)	0.15 to 0.18	1.0 to 1.2	Depends on the roof you choose
Sun’s heat let in through the roof	None, apart from roof windows	18% to 70%, depending on grade	Depends on the roof you choose
Time on site	3 to 6 days	2 to 4 days	Three to four weeks; about six for a large one (Which?)
Building regulations	Approval needed	Usually exempt when like for like	Usually exempt if glazed and under 30m²; approval needed for a solid roof
Frames, walls and base	Kept, and checked for strength	Kept	All new
Daylight through the roof	Low	The most	Depends on the roof you choose
Rain noise	Quietest	Quieter than polycarbonate	Depends on the roof you choose

Roof prices are our site-wide ranges for a medium conservatory across lean-to, Edwardian, Victorian and gable shapes, fitted; installers usually quote including VAT, but check. New conservatory figures are from the Federation of Master Builders (from £8,000, and £8,000 to £17,000 for a uPVC lean-to) and a May 2024 Checkatrade guide (£15,000 to £30,000, average £22,500). MyJobQuote puts the average conservatory at around £15,000. Size, style, base work and finish make a large difference.

When is a new roof enough?

When the structure underneath is sound. Building control will look at this for any solid roof, and a good installer should look for any roof. LABC’s checks cover:

• Steel in the frames. The frames that carry the roof should contain steel reinforcement, confirmed by drilling pilot holes or using a magnet. Frames built for a polycarbonate roof “may only have sufficient reinforcement to carry that particular load”.
• Foundations. Trial holes may be dug; in most cases a 150mm concrete strip foundation or slab on original ground is adequate.
• Signs of distress. Cracks or movement between the conservatory and the house are a warning sign, and LABC says inadequate foundations can cause settlement, cracks and leaks.

Age matters too. One national installer says frames 10 to 15 years old or damaged may not be strong enough, and a MoneySavingExpert contributor warned against putting a new roof on windows that have used up more than half their life. If only some frames fail the check, LABC says new windows or extra structural posts can be fitted, which is cheaper than a full rebuild. Read can my conservatory take a solid roof? before getting quotes.

Which is warmer in winter?

Whichever has the better roof. A tiled roof reaches 0.15 to 0.18 W/m²K; performance glass 1.0 to 1.2. A new conservatory with a glass roof will have modern glazing throughout, but an exempt conservatory does not have to meet any energy standard, so its performance depends entirely on what you specify. New frames and glazing in the walls help, and homeowners on MoneySavingExpert found the walls, windows and floor matter as well as the roof.

Which stays cooler in summer?

Again, the roof decides it. Which? warns that the more glass in the roof, the greater the chance of overheating, and 24% of its members surveyed in April 2026 said their conservatory’s temperature was difficult to regulate. A new conservatory with a clear glass roof on a south-facing wall will overheat much like the old one. If you rebuild, choose solar control glass or a solid roof from the start.

Light and noise

A new glass roof, on its own or on a new conservatory, keeps the most daylight. A tiled roof cuts light through the roof and is the quietest option in rain; glass sits in between, quieter than polycarbonate but louder than tiles. A rebuild gives you the chance to add roof windows or glazed panels in a solid roof exactly where you want them.

Cost and value for money

A new roof is almost always cheaper. Our typical figures are about £5,200 for a glass roof and £9,600 for a tiled roof on a medium conservatory. A whole new conservatory starts from about £8,000 on the FMB’s figures for a basic lean-to, and one 2024 guide gives £15,000 to £30,000 for a new build. Choosing a solid roof for a new conservatory adds more: Conservatory Outlet says a tiled roof upgrade typically adds £4,000 to £10,000 and a glass roof upgrade £2,000 to £5,000. Some homeowners on MoneySavingExpert reported complete hybrid rebuilds at around £9,000 to £10,000, which shows how widely prices vary.

Where a rebuild can be better value is when the roof is not the only thing failing. Paying for a new roof and then new frames a few years later costs more than doing both once. If the windows need replacing anyway, get a price for new windows and roof together, and one for a complete rebuild. See roof prices by type for the detail.

Building regulations, planning and paperwork

New roof. A glass or polycarbonate roof replacing a glazed roof is usually exempt if the conservatory still meets the exemption. A tiled or other solid roof needs a building regulations application, and you should get a completion certificate. See our building regulations guide.

New conservatory. A new conservatory is exempt from building regulations if it is at ground level, no more than 30m², separated from the house by external-quality doors, not heated by the house’s heating system, and its glazing and electrics comply. Any new opening between the house and the conservatory needs approval. A new conservatory with a solid roof falls outside the exemption. For planning, the Planning Portal says a conservatory falls under the same rules as any other home extension, so it must fit within permitted development limits or get permission. Rebuilding on the same footprint is usually straightforward, but a bigger or taller one may not be.

Looks and resale

A rebuild gets you new frames, a fresh look and the chance to change the shape. A new roof on old frames keeps the existing style, though a tiled roof changes the look considerably. No independent data shows what either adds to a sale price. What buyers’ solicitors will ask for is paperwork: the completion certificate for a solid roof, and evidence that a new conservatory met the exemption or was approved.

New roof or new conservatory: which should you choose?

• The frames have steel reinforcement, there are no cracks and the windows are in decent shape: new roof, tiled for comfort or glass for light.
• Some frames lack reinforcement but the rest is sound: new roof plus extra structural posts or replacement frames where needed.
• The windows are near the end of their life and the roof leaks too: get prices for a new roof with new windows and for a complete rebuild.
• The base is cracked or moving: have it assessed; a rebuild, or an extension, may be the only sound option.
• You want a different size or shape: new conservatory or extension, subject to planning.
• You want to use the room all year: whichever you choose, give it a solid or hybrid roof, or at least solar control glass.

When you get quotes, ask each firm how it checked your frames and base, and ask for a written price for what happens if more is found once the old roof is off. Our list of questions to ask an installer covers the rest.