Penwith · TR20
Sancreed 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 Sancreed, that work is shaped by the place itself — Sancreed is a rural parish in the TR20 area, with farmsteads, lanes and scattered homes defining its built character, with a building stock that leans toward scattered modern homes and rural cottages.
Sancreed sits in Penwith — covering TR20 from Penzance, Chyandour, New Mill outward.
- Cornwall AONB
- Rural / open-countryside policy area
- ✓ 30+ years of Cornwall Council approvals
- ✓ AONB experience built into the fee
- ✓ Cornwall Council regulars across every sub-area
- ✓ Free first site visit, no obligation
Who this is for
Sancreed 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
The TR20 constraints that shape a extension brief.
Watch #1
AONB landscape-impact scrutiny on visible elevations
Watch #2
Tighter Local Plan tests on isolated rural dwellings
Local proof — Most Sancreed homeowners come to us after a extension quote elsewhere felt vague on planning — we lead with feasibility instead.
Get a free feasibility viewFAQs
Sancreed 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 Sancreed specifically, we'd start by checking AONB landscape sensitivity 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.
- 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.
Local context
Why Sancreed is its own job.
Locally, open-countryside policy, access lanes, drainage and agricultural building history all need to be addressed before drawings go too far. For extension specifically, 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; 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 Sancreed projects parish-up, not template-down — the TR20 context shapes the design from day one. Whether the project is on scattered modern homes in the centre or further out toward Penzance, 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 Sancreed.
01
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
02
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.
03
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
04
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
Our process
How a Sancreed 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 TR20.
Building stock
Across Sancreed (TR20) we work on farmhouses, converted barns, rural cottages, smallholdings, scattered modern homes. Each stock type drives a different extension response — scattered modern homes in particular needs careful detailing here.
Parish & policy
Sancreed sits in the parish of Sancreed, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR20 from our studio, with regular extension jobs also running in Penzance, Chyandour, New Mill. Most Sancreed site visits get booked within the same week.
What does a first Sancreed consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR20 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitSancreed is part of Penzance
Sancreed sits inside the Penzance catchment — we cover both as one extension territory.
See Extensions in Penzance →Other services in Sancreed
Nearby places we cover
The extension jobs we're proudest of in Sancreed are the ones where the planning route was clear before a single elevation was drawn.