Mid Cornwall · TR3
Extensions Stithians: TR3 planning, Mid Cornwall fabric
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. What works on a TR3 plot rarely works elsewhere — Stithians is a village south of Redruth with the Stithians Reservoir nearby, a Norman church and a Conservation Area covering the village core, with a building stock that leans toward Victorian villas and traditional granite cottages.
Stithians sits in Mid Cornwall — covering TR3 from Ponsanooth, Constantine, Mabe Burnthouse outward.
- Conservation Area
- Rural / open-countryside policy area
- ✓ Free first site visit, no obligation
- ✓ 30+ years of Cornwall Council approvals
- ✓ Cornwall Council regulars across every sub-area
- ✓ Local to Mid Cornwall — not a national franchise
Local proof — Recent extension enquiries from Stithians have clustered around Victorian villas — we know the route through Cornwall Council on these.
Get a free feasibility viewLocal context
Why Stithians is its own job.
Conservation Area covers the village core. Reservoir SSSI to the south and A39 corridor shape edge-of-village development. That sets the scene before any design work begins. For extension specifically, parts of Stithians sit within a designated Conservation Area, which means materials, fenestration and roof pitches all need to read sympathetically with the existing streetscape; 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. It's the kind of detail that decides whether a Stithians application gets approved at eight weeks or stalls in committee. The Victorian villas that dominate Stithians (and continue out toward Mabe Burnthouse) set the tone for any extension scheme here.
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 Stithians.
01
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
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
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
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 Stithians 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 Stithians homeowners pick a local studio for extension.
Building stock
Across Stithians (TR3) we work on traditional granite cottages, Victorian villas, post-war bungalows, modern small estates, barn conversions. Each stock type drives a different extension response — Victorian villas in particular needs careful detailing here.
Parish & policy
Stithians is its own town in Mid Cornwall, with planning history that's specific to the TR3 catchment.
Coverage
We cover TR3 from our studio, with regular extension jobs also running in Ponsanooth, Constantine, Mabe Burnthouse. Most Stithians site visits get booked within the same week.
How quickly can you visit a Stithians site?
Usually within the same week. Stithians (TR3) is on our regular Mid Cornwall run, alongside Ponsanooth, Constantine, Mabe Burnthouse. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitFAQs
Stithians 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 Stithians specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- 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.
Other services in Stithians
Nearby places we cover
Designing a extension in Stithians is as much about reading the parish as reading the brief; we do both, and the planning outcomes follow.