Penwith · TR20
Design, planning and build for Madron extension
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. A TR20 site visit comes before a Madron sketch, every time — Madron is the parish village above Penzance with the medieval church (Penzance's mother church) and a strong inland Penwith character, with a building stock that leans toward traditional granite cottages and barn conversions.
Madron sits in Penwith — covering TR20 from Heamoor, Penzance outward.
- Conservation Area
- Rural / open-countryside policy area
- ✓ Conservation Area experience built into the fee
- ✓ 30+ years of Cornwall Council approvals
- ✓ Same team on paper as on site
- ✓ Fixed-fee planning packages, no surprise invoices
Local proof — We typically have one or two extension jobs live in the TR20 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewLocal context
Why Madron is its own job.
Cornwall Council's lens on Madron is consistent: conservation Area covers the village core including the church; AONB lies immediately to the north and west. Active parish council with detailed input on infill and replacement applications. For extension specifically, parts of Madron 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. That's why we treat every Madron project as a TR20-area job first — not a generic Cornwall job with a postcode bolted on. The traditional granite cottages that dominate Madron (and continue out toward Heamoor) 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 Madron.
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
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
03
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
04
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.
Our process
How a Madron 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 Madron (TR20) we work on traditional granite cottages, Georgian rectory-style houses, Victorian villas, modern infill bungalows, barn conversions. Each stock type drives a different extension response — traditional granite cottages in particular needs careful detailing here.
Parish & policy
Madron is its own town in Penwith, with planning history that's specific to the TR20 catchment.
Coverage
We cover TR20 from our studio, with regular extension jobs also running in Heamoor, Penzance. Most Madron site visits get booked within the same week.
How quickly can you visit a Madron site?
Usually within the same week. Madron (TR20) is on our regular Penwith run, alongside Heamoor, Penzance. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitFAQs
Madron 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 Madron specifically, we'd start by checking the Conservation Area boundary 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.
- 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.
- 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 Madron
Nearby places we cover
Most Madron extension enquiries start with one honest conversation about what's actually allowed — and that conversation costs nothing.