North Cornwall · PL15
One studio for extension in North Petherwin
Extensions are the bread and butter of Cornish homes — adding the kitchen-diner the original layout never had, the bedroom for a growing family, or the light and views the back of the house should always have had. The way we approach extension in North Petherwin starts with a measured walk-round — North Petherwin is a rural parish in the PL15 area, with farmsteads, lanes and scattered homes defining its built character, with a building stock that leans toward converted barns and smallholdings.
North Petherwin sits in North Cornwall — covering PL15 from Launceston, Warbstow, Boyton outward.
- Rural / open-countryside policy area
- ✓ One studio — design, planning and build under one roof
- ✓ Local to North Cornwall — not a national franchise
- ✓ 30+ years of Cornwall Council approvals
- ✓ Measured-survey accuracy from day one
Our process
How a North Petherwin extension project runs.
Step 1
Brief
We meet on site, talk through how you live now and what's missing from the current layout.
Step 2
Design
Two or three sketch directions with rough budgets, then refinement of the chosen route.
Step 3
Approvals
Planning or Cert of Lawfulness, then a full building regs package.
Step 4
Build
Either through your own builder with our drawings, or as a full build by our team.
Step 5
Handover
Snag, certify, hand over the keys to your new space.
Typical single-storey rear extensions run twelve to twenty weeks on site; two-storey and wraparound projects sixteen to thirty weeks.
Local proof — Most North Petherwin homeowners come to us after a extension quote elsewhere felt vague on planning — we lead with feasibility instead.
Get a free feasibility viewWhat we focus on
Extensions considerations specific to North Petherwin.
01
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
02
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
03
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
04
Permitted development for rear extensions runs to four metres on a detached house, three on a semi or terrace — but Article 4 areas remove this in some parishes.
Local context
Why North Petherwin is its own job.
Two things shape a North Petherwin application: parish character and policy. On policy — open-countryside policy, access lanes, drainage and agricultural building history all need to be addressed before drawings go too far. For extension specifically, Cornwall Council's Local Plan applies tighter tests to isolated rural dwellings here, so design rationale and policy fit need to be set out clearly from the outset. Get that local reading right and the rest of the North Petherwin programme tends to run on time. On converted barns in particular — the kind you'll also find toward South Petherwin — the extension brief always has to read the existing fabric first.
Planning note
Most extensions in Cornwall are either permitted development or a straightforward householder application — but Conservation Area and AONB sites need a more careful design conversation upfront.
Local watch-list
The PL15 constraints that shape a extension brief.
Watch #1
Tighter Local Plan tests on isolated rural dwellings
North Petherwin is part of Launceston
North Petherwin sits inside the Launceston catchment — we cover both as one extension territory.
See Extensions in Launceston →Local fabric
One PL15 studio, one extension job — start to finish.
Building stock
Across North Petherwin (PL15) we work on farmhouses, converted barns, rural cottages, smallholdings, scattered modern homes. Each stock type drives a different extension response — converted barns in particular needs careful detailing here.
Parish & policy
North Petherwin sits in the parish of North Petherwin, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL15 from our studio, with regular extension jobs also running in Launceston, Warbstow, Boyton. Most North Petherwin site visits get booked within the same week.
Can you handle both planning and build in North Petherwin?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing North Petherwin builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
North Petherwin runs the full mix — owner-occupier, holiday-let, commercial and the occasional smallholding — so we scope every extension enquiry from the use-class up.
FAQs
North Petherwin Extensions — local questions answered.
- What about the Party Wall Act?
- If you share a wall with a neighbour or build close to a boundary, the Act applies. We flag it early, recommend a surveyor and keep the programme aligned with the notice period. In North Petherwin specifically, we'd start by checking the latest parish-level planning history before committing to a direction.
- How much does an extension cost in Cornwall?
- Build costs in Cornwall typically run from around £2,200 to £3,200 per square metre for a good-quality single-storey extension, more for kitchen-grade fit-out or complex glazing. We give a realistic budget before drawings start, not after.
- Can you handle the build as well as the design?
- Yes — that's the whole point of the studio. One contract, one point of contact, no finger-pointing between architect and builder when something needs a decision on site.
- Do I need planning permission for an extension?
- Often no — single-storey rear extensions, side extensions and modest two-storey additions can sit inside permitted development on a typical detached house. Conservation Areas, AONB and Article 4 zones remove some of those rights, so we always check the address first.
- Will my house be liveable during the build?
- For most rear and side extensions, yes — we sequence the works so the kitchen and one bathroom stay functional until the new build is watertight and connected.
Other services in North Petherwin
Nearby places we cover
The PL15 stretch of North Cornwall has its own rhythm; our extension work respects it, and Cornwall Council usually responds in kind.