North Cornwall · PL27
Design, planning and build for Rock extension
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 PL27 site visit comes before a Rock sketch, every time — Rock is the affluent estuary village opposite Padstow, AONB-designated, with one of the highest property value markets per square metre in Cornwall and a strong replacement-dwelling planning history, with a building stock that leans toward high-end modern architect-designed coastal homes and post-war bungalows.
Rock sits in North Cornwall — covering PL27 from Polzeath, Padstow outward.
- Cornwall AONB
- Coastal exposure zone
- Rural / open-countryside policy area
- ✓ AONB experience built into the fee
- ✓ Fixed-fee planning packages, no surprise invoices
- ✓ Measured-survey accuracy from day one
- ✓ One studio — design, planning and build under one roof
Who this is for
Rock runs the full mix — owner-occupier, holiday-let, commercial and the occasional smallholding — so we scope every extension enquiry from the use-class up.
Local watch-list
The PL27 constraints that shape a extension brief.
Watch #1
AONB landscape-impact scrutiny on visible elevations
Watch #2
Coastal exposure driving fixing, render and joinery spec
Watch #3
Tighter Local Plan tests on isolated rural dwellings
Local proof — Most Rock homeowners come to us after a extension quote elsewhere felt vague on planning — we lead with feasibility instead.
Get a free feasibility viewFAQs
Rock Extensions — local questions answered.
- How long does the whole process take?
- Allow roughly three months for design and approvals, then twelve to twenty weeks on site for a typical single-storey extension. Wraparounds and two-storey add-ons take longer, mostly through approval and groundworks. In Rock specifically, we'd start by checking AONB landscape sensitivity before committing to a direction.
- 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.
- 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.
Local context
Why Rock is its own job.
Cornwall Council's lens on Rock is consistent: aONB and Heritage Coast designations apply; estuary views and cumulative development on the dunes are recurring planning themes. Replacement dwelling policy is a major planning route here. For extension specifically, the surrounding landscape falls inside the Cornwall Area of Outstanding Natural Beauty, so massing, height and landscape impact carry extra weight in any planning decision; coastal salt-laden air around Rock drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure; 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. That's why we treat every Rock project as a PL27-area job first — not a generic Cornwall job with a postcode bolted on. The high-end modern architect-designed coastal homes that dominate Rock (and continue out toward Padstow) 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 Rock.
01
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
02
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.
03
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
04
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.
Our process
How a Rock 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 a North Cornwall studio is the right fit for Rock extension.
Building stock
Across Rock (PL27) we work on 1930s and 1950s holiday villas, post-war bungalows, high-end modern architect-designed coastal homes, replacement dwellings on existing footprints. Each stock type drives a different extension response — high-end modern architect-designed coastal homes in particular needs careful detailing here.
Parish & policy
Rock sits in the parish of St Minver Lowlands, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL27 from our studio, with regular extension jobs also running in Polzeath, Padstow, Wadebridge. Most Rock site visits get booked within the same week.
How quickly can you visit a Rock site?
Usually within the same week. Rock (PL27) is on our regular North Cornwall run, alongside Polzeath, Padstow, Wadebridge. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitRock is the hub for these neighbourhoods
We run extensions across Rock and the surrounding PL27 neighbourhoods — same studio, same site team.
- Polzeath
PL27
Other services in Rock
Nearby places we cover
Local neighbourhoods in Rock
Most Rock extension enquiries start with one honest conversation about what's actually allowed — and that conversation costs nothing.