Conservatory Cost Calculator

A conservatory in the UK costs around £850 – £1,350 per m² for a lean-to, £950 – £1,500 per m² for an Edwardian and £1,000 – £1,500 per m² for a Victorian. Gable-fronted designs run £1,100 – £1,800 per m², and an orangery £1,400 – £2,500 per m². Those are installed prices per m² of floor with a uPVC frame, a polycarbonate roof and a standard concrete base and dwarf wall. The published guides behind these rates differ on VAT, so check whether each quote includes it. Roof, frame, ground and approvals move the figure from there.

Conservatory cost per m² by style

The shape sets the rate. More facets, more upright glass and more brickwork all mean more material and more fitting time for each square metre you end up with.

Style	Installed cost per m²	What it is
Lean-to	£850 – £1,350 per m²	A single sloping roof against the house wall. The cheapest shape.
Edwardian	£950 – £1,500 per m²	Square or rectangular, so it uses the floor space best.
Victorian	£1,000 – £1,500 per m²	A faceted bay front, which needs more frame and roof work.
Gable-fronted	£1,100 – £1,800 per m²	An upright glazed front, the most glass of the standard styles.
P-shape or T-shape	£950 – £1,450 per m²	A lean-to combined with a bay or projection, usually larger.
Orangery	£1,400 – £2,500 per m²	Brick piers and a solid flat roof with a glazed lantern.

Small conservatories cost more per m². The base, the fitting crew's days and the doors cost much the same whatever the size, so a small build sits towards the top of its range while a larger P-shape spreads those fixed costs further.

What changes the price

Roof. Polycarbonate is the baseline in every rate above. It is the cheapest roof, and also the noisiest and the least insulating. Solar control glass adds £125 – £300 per m² of floor and handles heat better. A solid tiled roof adds £350 – £650 per m², costs the most, and gives you a room you can sit in all year. It normally brings the conservatory under building regulations too. An orangery's solid roof and lantern are already inside its rate, so the roof choice does not change an orangery.

Frame. uPVC is the baseline. Aluminium costs 20-35% more and timber 30-50% more. The premium lands on the frame, glazing and roof, not on the base.

Base. The base, foundations and dwarf wall account for around £200 – £350 per m² of floor, and that is already inside the installed rates, not on top of them. The calculator shows it as its own line so you can see it, and drops it if you are reusing an existing base. Only do that once a surveyor or installer has confirmed the old base is sound. Sloping ground, poor soil or a drain under the footprint all add to the base cost.

Region. The shared planning model uses the Midlands as its baseline: London +20%, South East +10%, South West and East of England +5%, and the North, Scotland, Wales and Northern Ireland −10%. These are broad allowances, not measured regional averages; local quotes can differ.

What quotes leave out. Electrics, heating, flooring and blinds are rarely in the installed price. Nor is a new opening into the house. If an old conservatory has to come down first, taking it away costs £500 – £2,500, and the calculator adds that line when you tick the box. If you project manage the job yourself, read every quote against that list before you compare totals.

Building regulations and planning

In England and Wales a conservatory is exempt from building regulations if it is at ground level and has no more than 30m² of floor. Its glazing has to meet the safety glazing rules, and it must stay separated from the house by external-quality walls, doors or windows, with the house heating not extended into it. Break any of those and it needs approval. A new structural opening into the house always does, and any fixed electrics still have to comply. When approval applies, the calculator adds a full plans fee of £300 – £900 and an inspection fee of £500 – £800.

Scotland is stricter. A conservatory only avoids a building warrant up to 8m² and at least a metre from the boundary, so most need one. The warrant fee is set by the value of the work. Northern Ireland has its own building regulations and planning rules, so ask the council's building control team whether yours needs approval before you sign a quote.

For planning in England, a conservatory is treated as a single-storey extension under permitted development. It can go up to 3m deep on a semi or terrace and 4m on a detached house, or 6m and 8m under prior approval, which costs £249. It can be no higher than 4m, with eaves no higher than 3m within 2m of a boundary. Extensions and outbuildings together can cover no more than 50% of the garden, and a side conservatory can be no wider than half the original house.

Depth is measured from the original rear wall, so earlier extensions and conservatories count against it. The rule that materials must match the house does not apply to conservatories. None of this covers the front of the house, flats have no householder permitted development rights, conservation areas have tighter ones, and a listed building needs listed building consent even where the work is permitted development. Outside the limits you need a householder application, at £548. Run your plans through the permitted development checker before you pay a deposit.

Wales, Scotland and Northern Ireland each set their own permitted development rules and householder fees: £585, £371 and £347. Ask the council which route applies.

Conservatory or extension?

A single-storey extension runs around £2,650 – £3,000 per m² build-only, so a conservatory costs much less per m². The two are not priced on the same basis, though: the extension rate includes VAT, while the conservatory sources mix VAT-inclusive, VAT-exclusive and unstated figures. The extension rate also takes in electrics, plumbing and flooring that a conservatory price leaves out, and both are before professional fees. Confirm VAT on the conservatory quote before comparing totals. A conservatory is also a lighter structure, harder to keep warm in winter and cool in summer, and a solid roof or an orangery gets you closer to a room you can use all year.

A worked example

Take a 3.5m x 3.5m uPVC Edwardian conservatory with a polycarbonate roof on a detached house in the Midlands, on a new base. That is about 12m² of floor. The calculator starts from the Edwardian rate of £950 – £1,500 per m² and splits it in two: the frame, glazing, roof and fitting, and the base at £200 – £350 per m² as its own line. A polycarbonate roof adds no uplift and a uPVC frame adds no premium. The Midlands is the average, so no regional uplift applies either.

No fee lines appear. The floor is well under the 30m² building regulations exemption, and at 3.5m deep it sits inside the 4m permitted development limit for a detached house, so there is no building control or planning fee.

Enter those inputs in the calculator above for the total and the split between the two lines. If you do not know what is under the ground yet, hold 15-20% contingency on top for a sloping site, poor soil or a drain under the footprint.