West Cornwall · TR27
Gwithian extension — feasibility first, drawings second
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. In Gwithian, that work is shaped by the place itself — Gwithian is a coastal village in the TR27 area, where sea exposure, views and seasonal pressure shape most building decisions, with a building stock that leans toward rendered coastal houses and replacement dwellings.
Gwithian sits in West Cornwall — covering TR27 from Hayle, Angarrack, Phillack outward.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
- ✓ 30+ years of Cornwall Council approvals
- ✓ Conservation Area experience built into the fee
- ✓ Cornwall Council regulars across every sub-area
- ✓ Free first site visit, no obligation
Who this is for
Gwithian 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 Gwithian pitfalls we plan around.
Watch #1
Conservation Area material and fenestration controls in central Gwithian
Watch #2
AONB landscape-impact scrutiny on visible elevations
Watch #3
Coastal exposure driving fixing, render and joinery spec
Local proof — We typically have one or two extension jobs live in the TR27 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewFAQs
Gwithian 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 Gwithian specifically, we'd start by checking the Conservation Area boundary 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.
- 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.
- 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.
Local context
Why Gwithian is its own job.
Locally, coastal setting and landscape sensitivity mean rooflines, glazing, drainage and external materials need careful handling from the first sketch. For extension specifically, parts of Gwithian sit within a designated Conservation Area, which means materials, fenestration and roof pitches all need to read sympathetically with the existing streetscape; 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 Gwithian drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. Which is why we scope Gwithian projects parish-up, not template-down — the TR27 context shapes the design from day one. Whether the project is on rendered coastal houses in the centre or further out toward Hayle, the extension response is locally tuned.
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 Gwithian.
01
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.
02
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
03
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
04
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
Our process
How a Gwithian 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
Choosing a extension team that actually knows TR27.
Building stock
Across Gwithian (TR27) we work on granite cottages, rendered coastal houses, holiday homes, bungalows, replacement dwellings. Each stock type drives a different extension response — rendered coastal houses in particular needs careful detailing here.
Parish & policy
Gwithian sits in the parish of Gwithian, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR27 from our studio, with regular extension jobs also running in Hayle, Angarrack, Phillack. Most Gwithian site visits get booked within the same week.
What does a first Gwithian consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR27 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitGwithian is part of Hayle
Gwithian sits inside the Hayle catchment — we cover both as one extension territory.
See Extensions in Hayle →Other services in Gwithian
Nearby places we cover
The extension jobs we're proudest of in Gwithian are the ones where the planning route was clear before a single elevation was drawn.