South Cornwall · PL25 · Cornwall Council Central
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 — just off the A39; covering PL25 from St Austell, Bugle, St Dennis outward.
- Coastal exposure zone
- ✓coastal exposure experience built into the fee
- ✓Cornwall Council Central sub-area regulars
- ✓Free first site visit, no obligation
- ✓Plain-English feasibility before any drawings
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Free Carlyon Bay feasibility call
Tell us about your extension. We reply within 1 working day — no obligation.
Who this is for
In Carlyon Bay the extension brief is almost always a private homeowner improving a forever home — so we lead with feasibility and long-term value, not show-home rhetoric.
Local watch-list
Common Carlyon Bay pitfalls we plan around.
Watch #1
Exposure detailing on coastal bungalows — fixings, render systems and joinery specified for salt-laden air
Watch #2
Trussed roofs and shallow foundations in the later PL25 estates, which change the structural strategy
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.
- We live in the house. Can a extension in Carlyon Bay be done while we stay put?
- Usually yes for single-storey and rear work, with a temporary kitchen or bathroom arrangement agreed before the start. Whole-house remodels and roof work in Carlyon Bay are often easier if you move out for a few weeks. We set that expectation at feasibility stage rather than halfway through.
- 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.
Quick check
Want a straight answer on whether your Carlyon Bay project is worth pursuing?
Send a few details — we'll come back within 1 working day with a plain-English view on planning risk, likely cost band and whether it's a project we'd take on.
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Get a free feasibility view
For projects in Carlyon Bay and the PL25 area.
Scope
What we can draw, survey and build around Carlyon Bay
Not every project needs every stage. On a Carlyon Bay job we scope to what the site and the consent route actually require.
Structural coordination
Calculations coordinated with the drawings so building control sees one consistent story.
Planning application drawings
Existing and proposed plans, elevations, site and block plans drawn to validation standard.
Construction and technical drawings
1:10 and 1:20 details for the parts of the job builders normally have to guess at.
Measured survey
An accurate record of what is actually there, which is where most avoidable cost is removed.
Full design and build
One contract from first sketch to handover, with the same team on paper and on site.
Page purpose
Drawings only, or drawings through to handover in Carlyon Bay?
Both routes are open on a PL25 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Carlyon Bay clients take the drawings, tender them locally, then come back to us for the build if the numbers do not stack up.
- Route one: feasibility, planning and a tender-ready technical pack
- Route two: the same pack, then the build under one contract
- Either way the survey and feasibility work is identical, so the decision can wait
- Fees quoted per stage against the PL25 scope, not as one opaque figure
Keep reading
Follow the chain: survey, drawings, build
Carlyon Bay is covered from our St Austell run. Being a smaller place, the local detail matters more than the headline policy: lane access, neighbour proximity and what the immediate street already looks like.
Who this is for
Why this page exists, and who it is for
- Design and build are offered from the same studio, which means the person answering your Carlyon Bay questions has seen the detail built.
- Drawings, planning and building regulations are all produced in-house, so a extension enquiry does not get passed between firms.
- Applications for Carlyon Bay are handled through Cornwall Council, with Truro the nearest planning office we deal with regularly.
Planning rules change and every site is different. For the final position on your address, check with Cornwall Council as the local planning authority or the Planning Portal.
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
On a Carlyon Bay site the success of a extension is decided in week one — by reading the constraints right, not by drawing them away. Exposure detailing is a spec decision, not a finish decision, on this coast.
One conversation — and a clearer Carlyon Bay brief We know how coastal bungalows behave here.
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