North Cornwall · PL27
House extension costs in Polzeath — what PL27 homeowners actually pay
Most Polzeath cost questions land in the same bracket: a single-storey rear sits roughly £2,200–£2,800/m² built, a two-storey side runs £2,000–£2,500/m², and anything touching a coastal elevation tends to add 8–12% for materials and detailing. We quote on measured drawings, not guesses. 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. Every Polzeath project we take on begins with reading the local context — Polzeath is the surfing village above one of north Cornwall's biggest sandy beaches, AONB-designated, with a holiday-let-heavy housing stock and increasing replacement-dwelling activity, with a building stock that leans toward modern coastal architect builds and 1960s bungalows above the beach.
Polzeath sits in North Cornwall — covering PL27 from Rock, Trebetherick, St Minver outward.
- Cornwall AONB
- Coastal exposure zone
- Rural / open-countryside policy area
- ✓ Typical Polzeath single-storey rear: £55k–£85k build cost
- ✓ Two-storey side extension: £85k–£140k build cost
- ✓ Wrap-around / L-shaped: £110k–£180k build cost
- ✓ Design + planning + building regs fee from £4,800 (fixed)
Who this is for
Polzeath 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
Common Polzeath pitfalls we plan around.
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 — Recent extension enquiries from Polzeath have clustered around modern coastal architect builds — we know the route through Cornwall Council on these.
Get a free feasibility viewFAQs
Polzeath Extensions — local questions answered.
- What's the average cost of a single-storey extension in Polzeath?
- For a typical 20–30m² rear extension in Polzeath (PL27) we'd expect £55k–£85k including VAT, depending on glazing spec and whether the kitchen is being reworked. Coastal exposure here pushes weather-tightness specs up, which is real money.
- Do extension costs in Polzeath include planning and building regs?
- Our fixed-fee design package covers measured survey, planning drawings, building regs and a tendered cost plan. Build cost is separate and quoted from drawings — never guessed from a phone call.
- What pushes a Polzeath extension over budget?
- Three things: ground conditions you didn't survey for, a planning condition that drives a material change, and "while we're at it" scope creep. We screen all three at feasibility stage so the number you start with is the number you finish on.
- 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 Polzeath 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.
- 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.
Local context
Why Polzeath is its own job.
AONB and Heritage Coast designations across the village; cliff and dune-edge sites are tightly controlled. Local plan policy on second homes and holiday lets is being progressively tightened. That sets the scene before any design work begins. 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 Polzeath 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. It's the kind of detail that decides whether a Polzeath application gets approved at eight weeks or stalls in committee. The modern coastal architect builds that dominate Polzeath (and continue out toward Rock) 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 Polzeath.
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 Polzeath 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 Polzeath homeowners pick a local studio for extension.
Building stock
Across Polzeath (PL27) we work on 1930s coastal villas, 1960s bungalows above the beach, modern coastal architect builds, high-end replacement dwellings. Each stock type drives a different extension response — modern coastal architect builds in particular needs careful detailing here.
Parish & policy
Polzeath sits in the parish of St Minver, 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 Rock, Trebetherick, St Minver. Most Polzeath site visits get booked within the same week.
How quickly can you visit a Polzeath site?
Usually within the same week. Polzeath (PL27) is on our regular North Cornwall run, alongside Rock, Trebetherick, St Minver. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitPolzeath is the hub for these neighbourhoods
We run extensions across Polzeath and the surrounding PL27 neighbourhoods — same studio, same site team.
- Rock
PL27
- Trebetherick
PL27
Other services in Polzeath
Nearby places we cover
Local neighbourhoods in Polzeath
If you're scoping an extension in Polzeath, the honest number depends on three things: ground conditions, finish level and how much of the existing fabric stays. We'll tell you which bracket you're in before you commit to a fee.
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