North Cornwall · PL29
Extensions for Trelights (PL29)
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 Trelights starts with a measured walk-round — Trelights is a rural parish in the PL29 area, with farmsteads, lanes and scattered homes defining its built character, with a building stock that leans toward rural cottages and scattered modern homes.
Trelights sits in North Cornwall — covering PL29 from Port Isaac, Truro, St Austell outward.
- Rural / open-countryside policy area
- ✓ Fixed-fee planning packages, no surprise invoices
- ✓ Measured-survey accuracy from day one
- ✓ Same team on paper as on site
- ✓ Plain-English feasibility before any drawings
Our process
How a Trelights 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 Trelights 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 Trelights.
01
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
02
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
03
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.
04
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.
Local context
Why Trelights is its own job.
In Trelights 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 Trelights (PL29) project different from a generic Cornwall scheme — and is the whole reason we work this way. On rural cottages in particular — the kind you'll also find toward Newquay — 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
Trelights-specific issues we screen on the first visit.
Watch #1
Tighter Local Plan tests on isolated rural dwellings
Trelights is part of Port Isaac
Trelights sits inside the Port Isaac catchment — we cover both as one extension territory.
See Extensions in Port Isaac →Local fabric
One PL29 studio, one extension job — start to finish.
Building stock
Across Trelights (PL29) we work on farmhouses, converted barns, rural cottages, smallholdings, scattered modern homes. Each stock type drives a different extension response — rural cottages in particular needs careful detailing here.
Parish & policy
Trelights sits in the parish of Trelights, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL29 from our studio, with regular extension jobs also running in Port Isaac, Truro, St Austell. Most Trelights site visits get booked within the same week.
Can you handle both planning and build in Trelights?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing Trelights builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
Trelights 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
Trelights Extensions — local questions answered.
- 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. In Trelights specifically, we'd start by checking the latest parish-level planning history 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.
- 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.
- 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.
Other services in Trelights
Nearby places we cover
The PL29 stretch of North Cornwall has its own rhythm; our extension work respects it, and Cornwall Council usually responds in kind.