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Launceston flat roof extensions, designed and built

Our design and build teams take on flat roof extensions in Launceston, from the first measured survey through planning and building control to the finished room.

  • Guide price in LauncestonFrom £21,000 inc VAT
  • PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
  • Build time10–16 weeks on site
  • Postcode districtsPL15
Flat roof of an extension with a membrane finish, a roof lantern and flat rooflights

When a flat roof extension makes sense

  • Homeowners who want maximum light from above
  • Extensions under first-floor windows where a pitch will not fit
  • Modern and 1930s onwards houses

Height is often what decides a flat roof. Under first-floor windows, a pitched roof may not fit at all; a flat roof keeps the extension low while still giving a good ceiling height inside.

What should I budget for a flat roof extension in Launceston?

Labour and material costs vary across the UK, so for Launceston we use our South West England factor (×1.02). The ranges include VAT and exclude design, structural and council fees.

Typical rates in Launceston: £1,780 to £3,420 per m² including VAT, depending on specification.

SizeEssentialStandardPremium
3 m × 4 m
12 m²
£21,000 – £25,500£25,000 – £32,000£31,500 – £41,500
4 m × 5 m
20 m²
£35,500 – £42,000£41,500 – £53,500£53,000 – £68,500
5 m × 6 m
30 m²
£53,500 – £63,000£62,500 – £80,000£79,500 – £103,000

Try the guide-price tool to see a range for your own size and finish.

Working in Launceston

Our survey diary covers Launceston, including PL15. Nearby, we also take on projects in Bodmin (18 miles), St Austell (26 miles), Newquay (33 miles), Truro (38 miles).

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.

Planning and approvals in Launceston

In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.

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.

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).

Our process, step by step

Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.

  1. Free site visit

    A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.

  2. Design and approvals

    We draw the design, agree it with you and handle planning or permitted development checks and building regulations.

  3. Fixed written price

    The price is fixed in writing once the design is settled, with a clear programme and payment stages.

  4. Build and sign-off

    We build it with one project manager, book the building control inspections and hand over the completion certificate.

Common questions in Launceston

Do I need building regulations approval in Launceston?

Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.

How long does a flat roof extension take to build in Launceston?

On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Launceston, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.

Can I walk on a flat roof extension?

Only for maintenance unless it is designed as a terrace. A roof terrace or balcony needs planning permission and a different structure.

Are flat roof extensions cheaper?

Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,780 to £3,420 per m² including VAT.

Book a free site visit in Launceston

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 .

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