South Cornwall · PL22
Extensions for St Winnow (PL22)
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. Working in St Winnow means starting from the PL22 context — St Winnow is a rural parish in the PL22 area, with farmsteads, lanes and scattered homes defining its built character, with a building stock that leans toward farmhouses and rural cottages.
St Winnow sits in South Cornwall — covering PL22 from Lostwithiel, Lerryn, Lanlivery outward.
- Rural / open-countryside policy area
- ✓ Local to South Cornwall — 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 St Winnow 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 — Recent extension enquiries from St Winnow have clustered around farmhouses — we know the route through Cornwall Council on these.
Get a free feasibility viewWhat we focus on
Extensions considerations specific to St Winnow.
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 St Winnow is its own job.
In St Winnow the planning picture is specific: open-countryside policy, access lanes, drainage and agricultural building history all need to be addressed before drawings go too far. For extension specifically, 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 St Winnow (PL22) project different from a generic Cornwall scheme — and is the whole reason we work this way. On farmhouses in particular — the kind you'll also find toward Sweetshouse — 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
The PL22 constraints that shape a extension brief.
Watch #1
Tighter Local Plan tests on isolated rural dwellings
St Winnow is part of Lostwithiel
St Winnow sits inside the Lostwithiel catchment — we cover both as one extension territory.
See Extensions in Lostwithiel →Local fabric
What sets a St Winnow extension brief apart.
Building stock
Across St Winnow (PL22) we work on farmhouses, converted barns, rural cottages, smallholdings, scattered modern homes. Each stock type drives a different extension response — farmhouses in particular needs careful detailing here.
Parish & policy
St Winnow sits in the parish of St Winnow, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL22 from our studio, with regular extension jobs also running in Lostwithiel, Lerryn, Lanlivery. Most St Winnow site visits get booked within the same week.
Can you handle both planning and build in St Winnow?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing St Winnow builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
St Winnow 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
St Winnow Extensions — local questions answered.
- How much does an extension cost in St Winnow?
- 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 St Winnow specifically, we'd start by checking the latest parish-level planning history 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.
- 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.
Other services in St Winnow
Nearby places we cover
If you're balancing ambition against PL22 planning realism, our St Winnow extension work threads that needle without the usual drama.