North Cornwall · PL28
Extensions St Merryn: PL28 planning, North Cornwall fabric
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. A PL28 site visit comes before a St Merryn sketch, every time — St Merryn is a rural parish in the PL28 area, with farmsteads, lanes and scattered homes defining its built character, with a building stock that leans toward scattered modern homes and smallholdings.
St Merryn sits in North Cornwall — covering PL28 from Padstow, St Eval, Trevone outward.
- Rural / open-countryside policy area
- ✓ Plain-English feasibility before any drawings
- ✓ rural policy area experience built into the fee
- ✓ Free first site visit, no obligation
- ✓ One studio — design, planning and build under one roof
Local proof — Our North Cornwall workload means a St Merryn extension project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewLocal context
Why St Merryn is its own job.
Open-countryside policy, access lanes, drainage and agricultural building history all need to be addressed before drawings go too far. That sets the scene before any design work begins. 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. It's the kind of detail that decides whether a St Merryn application gets approved at eight weeks or stalls in committee. The scattered modern homes that dominate St Merryn (and continue out toward Trevone) set the tone for any extension scheme here.
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.
What we focus on
Extensions considerations specific to St Merryn.
01
Extensions over a certain proportion of the original house trigger full Part L upgrade obligations to the existing building — worth knowing before brief is set.
02
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
03
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.
04
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
Our process
How a St Merryn 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 fabric
Why St Merryn homeowners pick a local studio for extension.
Building stock
Across St Merryn (PL28) we work on farmhouses, converted barns, rural cottages, smallholdings, scattered modern homes. Each stock type drives a different extension response — scattered modern homes in particular needs careful detailing here.
Parish & policy
St Merryn sits in the parish of St Merryn, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL28 from our studio, with regular extension jobs also running in Padstow, St Eval, Trevone. Most St Merryn site visits get booked within the same week.
How quickly can you visit a St Merryn site?
Usually within the same week. St Merryn (PL28) is on our regular North Cornwall run, alongside Padstow, St Eval, Trevone. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitFAQs
St Merryn Extensions — local questions answered.
- 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. In St Merryn specifically, we'd start by checking the latest parish-level planning history before committing to a direction.
- 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.
- 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.
- 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.
- 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.
St Merryn is part of Padstow
St Merryn sits inside the Padstow catchment — we cover both as one extension territory.
See Extensions in Padstow →Other services in St Merryn
Nearby places we cover
Most St Merryn extension enquiries start with one honest conversation about what's actually allowed — and that conversation costs nothing.