A conservatory sounds like a good idea. More space. More sunlight. No planning permission. And all for a reasonable price.
At least, that’s what the salesmen said. And by God it worked.
Britain is littered with conservatories. Unfortunately, many of them from the 90s and 00s are pretty unusable. Too hot in summer. Too cold in winter. All thanks to their cheap polycarbonate roofs.
The solution is to get a new conservatory roof, with better insulation.
How much does a new conservatory roof cost?
A new conservatory roof costs £9,997, and ranges from £5,500-£24,000. That’s according to 23 individual prices from real people on forums. Full list below:
| URL | Sample Size | Lowest Price (£) | Highest Price (£) | Average Price (£) | Date of First Post |
| Money Saving Expert | 3 | 4,500 | 9,500 | 7,333 | 31 October 2022 |
| Mumsnet | 5 | 5,500 | 7,500 | 6,940 | 22 April 2020 |
| Mumsnet | 7 | 8,000 | 24,000 | 14,142 | 21 April 2023 |
| Pistonheads | 8 | 6,000 | 13,000 | 9,281 | 21 May 2021 |
| Totals | 23 | 5,500 | 24,000 | 9,997 |
As you can see, there has certainly been some price inflation since 2020, and you tend to pay more in the South East too. Prices do vary, and this is one of those jobs where you’ll only get a true feeling for value by getting a few quotes.
One major element in the price is the type of roof you’d like.
What types of conservatory roof are there?
There are four main types of conservatory roof: solid, glass, hybrid, and polycarbonate.
Polycarbonate roofs are the cheapest and nastiest type of roof. They are just sheets of lightweight plastic that keep the rain out, but don’t do much else. Usually this is what you’ll want to replace.
Solid roofs can be tiled, like the roof of a house (although usually with a lighter weight material). Or they can be clad in metal, such as aluminium or zinc. Or they can use proprietary systems that slot into the existing frame. A solid roof has excellent insulation, looks great, and essentially turns your conservatory into a proper extension. The downsides are the price, and of course you do sacrifice the light from above.
Glass roofs are a like-for-like replacement for polycarbonate roofs. You’ll keep the light, but double-glazed glass is much better at insulating (roughly twice as good). Glass isn’t cheap, in fact it’s often the most expensive option. Also it’s heavy, so you might also have to reinforce the roof structure.
Hybrid roofs are essentially solid roofs with skylights. Best of both worlds.
Why do conservatories get too hot and cold?
It’s all down to poor insulation. Conservatories are far leakier than the rest of the house. There are the seals around the glass, and the floors can be poorly insulated too. However, by far the biggest factor is the roof.
Before 2010, many conservatory roofs were made with polycarbonate. And polycarbonate – while cheap – is not a great insulator. Insulation is measured in ‘U-values’, which denotes how much heat can escape. Lower is better.
Here’s how different roofs compare:
- Polycarbonate U-value: 1.6 to 2.4
- Double-glazing U-value: 1 to 1.4
- Solid roof U-value: 0.15 to 0.3
If you have an old conservatory, the U-value of your roof will likely be over 1, or even over 2. Even if it’s double-glazed, you may still be leaking heat, as old double-glazing had far worse U-values than modern glass.
Will a conservatory roof add value to my home?
There’s little evidence for this. That’s not a no – it’s just simply not possible to measure sale price in such detail.
Common sense says that a conservatory with a proper roof will be more saleable. Imagine yourself as a buyer, standing in a freezing conservatory on a winter’s day.
‘No thanks.’
However, that doesn’t mean that a new roof will solve that problem entirely. If a buyer is looking at a floorplan with a conservatory on it, they may just subtract that floor space from the total (I know I do).
The best reason to get a new conservatory roof is to make your conservatory a nicer place to be. And it certainly achieves that.
Are there other alternatives to a new conservatory roof?
Yes. You can knock it down and start again.
You can get an entirely new conservatory. The quality of double-glazing has improved a lot in the last 30 years, and it’ll be much better insulated.
You could also replace it with a proper extension. You may be able to use the same foundations, and it genuinely will add value to your home. Of course it’s the most expensive option.
