Penwith · TR19
Extensions for Porthcurno (TR19)
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. The way we approach extension in Porthcurno starts with a measured walk-round — Porthcurno is the cliff-cove village home to the Minack Theatre and the historic transatlantic telegraph station, AONB and Heritage Coast designated, with a building stock that leans toward modern carefully detailed coastal homes and former telegraph-era houses.
Porthcurno sits in Penwith — covering TR19 from Sennen, St Buryan, Lamorna outward.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
- Rural / open-countryside policy area
- ✓ Local to Penwith — not a national franchise
- ✓ Same team on paper as on site
- ✓ One studio — design, planning and build under one roof
- ✓ Measured-survey accuracy from day one
Our process
How a Porthcurno 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 proof — Most Porthcurno homeowners come to us after a extension quote elsewhere felt vague on planning — we lead with feasibility instead.
Get a free feasibility viewWhat we focus on
Extensions considerations specific to Porthcurno.
01
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
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
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.
04
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
Local context
Why Porthcurno is its own job.
In Porthcurno the planning picture is specific: conservation Area covers the village and the telegraph station heritage area; AONB and Heritage Coast across the parish. Cliff exposure and views from the South West Coast Path are weighed in every application. For extension specifically, parts of Porthcurno 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 Porthcurno 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. That local reading is what makes a Porthcurno (TR19) project different from a generic Cornwall scheme — and is the whole reason we work this way. On modern carefully detailed coastal homes in particular — the kind you'll also find toward Sennen — the extension brief always has to read the existing fabric first.
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.
Local watch-list
What usually catches extension projects out in Porthcurno.
Watch #1
Conservation Area material and fenestration controls in central Porthcurno
Watch #2
AONB landscape-impact scrutiny on visible elevations
Watch #3
Coastal exposure driving fixing, render and joinery spec
Watch #4
Tighter Local Plan tests on isolated rural dwellings
Porthcurno is part of Sennen
Porthcurno sits inside the Sennen catchment — we cover both as one extension territory.
See Extensions in Sennen →Local fabric
Porthcurno extensions — the local-studio difference.
Building stock
Across Porthcurno (TR19) we work on granite cottages, former telegraph-era houses, Edwardian villas, modern carefully detailed coastal homes. Each stock type drives a different extension response — modern carefully detailed coastal homes in particular needs careful detailing here.
Parish & policy
Porthcurno sits in the parish of St Levan, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR19 from our studio, with regular extension jobs also running in Sennen, St Buryan, Lamorna. Most Porthcurno site visits get booked within the same week.
Can you handle both planning and build in Porthcurno?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing Porthcurno builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
Porthcurno runs the full mix — owner-occupier, holiday-let, commercial and the occasional smallholding — so we scope every extension enquiry from the use-class up.
FAQs
Porthcurno Extensions — local questions answered.
- How much does an extension cost in Porthcurno?
- 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. In Porthcurno specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- 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.
- 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.
Other services in Porthcurno
Nearby places we cover
The TR19 stretch of Penwith has its own rhythm; our extension work respects it, and Cornwall Council usually responds in kind.