South Cornwall · PL25
Carlyon Bay 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 Carlyon Bay, that work is shaped by the place itself — Carlyon Bay is a holiday-coast settlement in the PL25 area, with strong second-home demand and exposed coastal building conditions, with a building stock that leans toward holiday lets and replacement dwellings.
Carlyon Bay sits in South Cornwall — covering PL25 from St Austell, Bugle, St Dennis outward.
- Coastal exposure zone
- ✓ coastal exposure experience built into the fee
- ✓ Cornwall Council regulars across every sub-area
- ✓ Free first site visit, no obligation
- ✓ Plain-English feasibility before any drawings
Who this is for
Carlyon Bay 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 Carlyon Bay pitfalls we plan around.
Watch #1
Coastal exposure driving fixing, render and joinery spec
Local proof — Our South Cornwall workload means a Carlyon Bay extension project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewFAQs
Carlyon Bay 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 Carlyon Bay 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.
- 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.
- 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 Carlyon Bay is its own job.
Locally, planning scrutiny often focuses on visual impact, occupancy, parking, overlooking and whether replacement buildings respect the coastal edge. For extension specifically, coastal salt-laden air around Carlyon Bay drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. Which is why we scope Carlyon Bay projects parish-up, not template-down — the PL25 context shapes the design from day one. Whether the project is on holiday lets in the centre or further out toward St Austell, 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 Carlyon Bay.
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
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
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
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 Carlyon Bay 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 Carlyon Bay homeowners pick a local studio for extension.
Building stock
Across Carlyon Bay (PL25) we work on coastal bungalows, holiday lets, second homes, detached houses, replacement dwellings. Each stock type drives a different extension response — holiday lets in particular needs careful detailing here.
Parish & policy
Carlyon Bay sits in the parish of Carlyon Bay, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL25 from our studio, with regular extension jobs also running in St Austell, Bugle, St Dennis. Most Carlyon Bay site visits get booked within the same week.
What does a first Carlyon Bay consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a PL25 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitCarlyon Bay is part of St Austell
Carlyon Bay sits inside the St Austell catchment — we cover both as one extension territory.
See Extensions in St Austell →Other services in Carlyon Bay
Nearby places we cover
The extension jobs we're proudest of in Carlyon Bay are the ones where the planning route was clear before a single elevation was drawn.