Orangery extensions in St Austell
If you live in St Austell and want more space without moving, an orangery extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in St AustellFrom £30,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 weeks on site
- Postcode districtsPL25

Is an orangery extension right for your house?
- Homeowners replacing an older conservatory
- Those who want daylight without overheating
- Period and detached houses with a garden view
The lantern-to-roof ratio sets the character. A wider solid perimeter gives a calmer, more room-like space and hides downlights and speakers; a bigger lantern feels brighter but needs more care against summer heat.
Extensions in and around St Austell
We cover St Austell and the postcode districts PL25. The same team covers Bodmin (9 miles), Truro (13 miles), Newquay (14 miles), Falmouth (18 miles), all within easy reach.
For homes towards Devon, Plymouth is around 28 miles away. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
Do I need planning permission in St Austell?
In England a glazed or orangery-style extension follows the same size limits as any single-storey rear extension: 3 m or 4 m without an application, or up to 6 m and 8 m through prior approval. Building regulations limit glazing to about a quarter of the new floor area plus the openings it replaces, unless whole-house calculations show the design still performs.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Orangery extension prices in St Austell
Labour and material costs vary across the UK, so for St Austell we use our South West England factor (×1.02). The ranges include VAT and exclude design, structural and council fees.
Typical rates in St Austell: £2,450 to £4,590 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £30,500 – £37,000 | £34,000 – £43,000 | £41,500 – £55,500 |
| 4 m × 4 m 16 m² | £39,000 – £47,500 | £45,500 – £57,500 | £55,000 – £73,500 |
| 4 m × 6 m 24 m² | £58,500 – £71,000 | £68,500 – £86,000 | £83,000 – £110,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about orangery extensions
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for St Austell, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in St Austell be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do you cover all of St Austell?
Yes. We cover St Austell and the surrounding parts of Cornwall. Site visits are free and there is no obligation.
How much does an orangery cost?
Our guide range is about £2,450 to £4,590 per m² including VAT, so a 16 m² standard-spec orangery is typically £45,500 to £57,500 in St Austell.
What is the difference between an orangery and a conservatory?
An orangery has a solid roof perimeter with a central lantern and more solid wall, so it is warmer and more like a room. A conservatory is mostly glass. Building regulations treat a heated orangery joined to the house as an extension.
Book a free site visit in St Austell
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.