South Cornwall · PL26 · Cornwall Council Mid
Pentewan 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. Anchor any Pentewan extension in the local fabric and the rest follows — Pentewan is an AONB former china clay shipping village south of St Austell, with a tight planned Conservation Area around the silted-up harbour and the holiday park inland, with a building stock that leans toward modern AONB-sensitive infill and Edwardian houses.
Pentewan sits in South Cornwall — just off the B3273; with Truro the closest city; 0 miles from Pentewan, 5 miles from St Austell.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
- Rural / open-countryside policy area
- ✓Free first site visit, no obligation
- ✓Plain-English feasibility before any drawings
- ✓30+ years of Cornwall Council approvals
- ✓Conservation Area experience built into the fee
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Free Pentewan feasibility call
Tell us about your extension. We reply within 1 working day — no obligation.
Local proof — We typically have one or two extension jobs live in the PL26 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewLocal context
Why Pentewan is its own job.
Locally, conservation Area covers the harbour village; AONB across the parish. Former harbour silting and Pentewan Sands holiday park shape most local planning conversations. For extension specifically, parts of Pentewan 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 Pentewan 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. Which is why we scope Pentewan projects parish-up, not template-down — the PL26 context shapes the design from day one. Whether the project is on modern AONB-sensitive infill in the centre or further out toward Gorran Haven, 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 Pentewan.
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.
Who this is for
Why this page exists, and who it is for
- Designated-area work is routine here, so heritage and landscape statements are produced alongside the drawings rather than outsourced.
- Sites we know on the ground here include the area around the inner harbour and Polkirt Hill.
- Drawings, planning and building regulations are all produced in-house, so a extension enquiry does not get passed between firms.
- Design and build are offered from the same studio, which means the person answering your Pentewan questions has seen the detail built.
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.
Keep reading
Follow the chain: survey, drawings, build
Pentewan works as a hub for us: the same extension team covers Pentewan and the surrounding PL26 villages, so a site visit here often takes in more than one address.
Page purpose
Drawings only, or drawings through to handover in Pentewan?
Both routes are open on a PL26 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Pentewan 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 PL26 scope, not as one opaque figure
Scope
What we can draw, survey and build around Pentewan
Not every project needs every stage. On a Pentewan job we scope to what the site and the consent route actually require.
Planning application drawings
Existing and proposed plans, elevations, site and block plans drawn to validation standard.
Full design and build
One contract from first sketch to handover, with the same team on paper and on site.
Measured survey
An accurate record of what is actually there, which is where most avoidable cost is removed.
Construction and technical drawings
1:10 and 1:20 details for the parts of the job builders normally have to guess at.
Heritage and design statements
Written justification where designation makes the design case as important as the drawing.
Our process
How a Pentewan 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.
Quick check
Want a straight answer on whether your Pentewan 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 Pentewan and the PL26 area.
Local fabric
Why Pentewan homeowners pick a local studio for extension.
Building stock
Across Pentewan (PL26) we work on planned harbour cottages, Victorian villas, Edwardian houses, modern AONB-sensitive infill, holiday park static caravans. Each stock type drives a different extension response — modern AONB-sensitive infill in particular needs careful detailing here.
Parish & policy
Pentewan sits in the parish of St Austell Bay, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL26 from our studio, with regular extension jobs also running in Pentewan, St Austell, Gorran Haven. Most Pentewan site visits get booked within the same week.
What does a first Pentewan consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a PL26 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitRecent work nearby
Inner-harbour cottage we worked on retained the slate-hung gable and reorganised behind.
See more recent South Cornwall work →FAQs
Pentewan Extensions — local questions answered.
- 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. In Pentewan specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- Who do you usually work for in Pentewan?
- A genuine mix: owner-occupiers, second-home and holiday-let owners, small commercial clients and the occasional smallholding. That matters because the right route for a extension depends on how the property is used, not just what it looks like, so we scope from the use first.
- 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.
Pentewan is the hub for these neighbourhoods
We run extensions across Pentewan and the surrounding PL26 neighbourhoods — same studio, same site team.
- Pentewan
PL26
Other services in Pentewan
Nearby places we cover
Local neighbourhoods in Pentewan
For Pentewan homeowners weighing up a extension, the right starting point is honest feasibility — that's what we lead with, before any drawings. Lane access and rural policy tests shape what is realistic on an isolated plot.
Start a Pentewan project with us We know how planned harbour cottages behave here.
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