The Short Answer
On our estimates, a uPVC conservatory of about 3.5m x 3.5m costs £9,000 to £15,000 for a lean-to, £10,000 to £16,500 for an Edwardian and £11,500 to £18,000 for a Victorian, built on a new base. Timber costs about a third more.
Most conservatories don't need planning permission or building regulations approval, which helps make them cheaper and quicker than an extension. The catch is comfort: Which?'s members name temperature as the top regret, because an all-glass room acts like a greenhouse, too hot in summer and cold in winter. If you want a room you'll use all year, I'd price a solid roof or an orangery too.
Conservatory prices by style
| Style | About 12.25m², supplied and built |
|---|---|
| Lean-to (uPVC) | £9,000 to £15,000 |
| Edwardian (uPVC) | £10,000 to £16,500 |
| Victorian (uPVC) | £11,500 to £18,000 |
| Timber Victorian | £15,000 to £24,000 |
Planning permission
A conservatory is an extension in planning terms, so the same permitted development limits apply on a house in England: a rear conservatory up to 3m deep (4m detached) and 4m high, side conservatories single storey and no wider than half the house, and nothing forward of the front wall. Unlike other extensions it doesn't have to match the house's materials. Full rules and a checker on our house extension page.
When a conservatory is exempt from building regulations
A conservatory is exempt if all of these are true:
- it's at ground level with a floor area under 30m²;
- its glazing meets the safety glass rules;
- the wall, door or window between it and the house stays (or is replaced with another wall, door or window);
- the house's heating isn't extended into it.
Which style?
- Lean-to: the cheapest; I think it suits low first-floor windows and bungalows.
- Edwardian: square or rectangular; in my view the most usable floor for the money.
- Victorian: a faceted bay end; it looks good, but I think furniture fits less easily.
- Timber: about a third dearer on our estimates, and timber needs regular repainting.
- Which way it faces matters as much as the style: Which? notes orientation has a big effect on temperature.
Conservatory or extension?
Which? lists the advantages of a conservatory: it can often go up under permitted development, it's generally faster to build, it lets in more light and it usually costs less. The downside is the one its members regret most, the temperature, and some wish they'd built an extension instead. On our estimates, a 12.25m² uPVC Edwardian is £10,000 to £16,500 against £29,400 to £39,200 to build an extension of the same size, before fees.
Get conservatory quotes
Conservatory companies price by style, size and frame. These are the questions they ask first.
Free, no obligation. We're paid by MyJobQuote when a tradesperson buys your job, never by you.
Frequently asked questions
How much does a conservatory cost?
On our estimates, about £9,000 to £15,000 for a 3.5m x 3.5m uPVC lean-to and £11,500 to £18,000 for a Victorian, built on a new base, including VAT.
Is it cheaper to get a conservatory or extension?
A conservatory: £10,000 to £16,500 for a typical uPVC Edwardian against £29,400 to £39,200 to build an extension of the same size, before fees, on our estimates. But it's a less comfortable room.
How much would a 12x12 conservatory cost?
If you mean 12 by 12 feet (about 3.7m square), that's close to our 12.25m² example: £9,000 to £15,000 for a uPVC lean-to to £11,500 to £18,000 for a Victorian, on our estimates.
Do I need planning permission for a conservatory?
Not usually, on a house in England, if it's within the extension limits: up to 3m deep at the back (4m detached) and 4m high, among others.
Does a conservatory need building regulations?
Not if it's at ground level, under 30m², has safety glazing, stays separated from the house by a door or wall, and has no heating from the house's system.
How we priced thisView sources (5, 4 official)
Rules come from the legislation and official guidance, read at source. Prices are our estimates: we check them against trade price data, retailer shelf prices and specialists' price lists, then build them up from their parts so the totals add up. Below are the sources behind the page; the trade price guides we only compare against aren’t listed. Where sources disagreed, we've said so. More on our method.
- Industry5 common conservatory regrets and how to avoid them (29 April 2026), Which?. Checked 15 Oct 2026.
- OfficialThe Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2 Part 1, legislation.gov.uk. Checked 16 Oct 2026.
- OfficialThe Building Regulations 2010, Schedule 2: exempt buildings and work (Classes 6 and 7), legislation.gov.uk. Checked 15 Oct 2026.
- OfficialApproved Document L: Conservation of fuel and power, Volume 1 Dwellings (2021 edition incorporating 2023 amendments), GOV.UK. Checked 16 Oct 2026.
- OfficialI want to redecorate my house (15 May 2013), Historic England. Checked 15 Oct 2026.
