North Cornwall · PL29 · Cornwall Council North
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 — just off the A39; 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
Free · No obligation
Free Trelights feasibility call
Tell us about your extension. We reply within 1 working day — no obligation.
Page purpose
Drawings only, or drawings through to handover in Trelights?
Both routes are open on a PL29 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Trelights clients take the drawings, tender them locally, then come back to us for the build if the numbers do not stack up.
- Route one: feasibility, planning and a tender-ready technical pack
- Route two: the same pack, then the build under one contract
- Either way the survey and feasibility work is identical, so the decision can wait
- Fees quoted per stage against the PL29 scope, not as one opaque figure
Scope
Scope options for Trelights clients
Clients in Trelights take different slices of this list, and that is deliberate.
Full design and build
One contract from first sketch to handover, with the same team on paper and on site.
Building regulation drawings
Full Plans sets with sections, construction notes and coordinated structural information.
Structural coordination
Calculations coordinated with the drawings so building control sees one consistent story.
Planning application drawings
Existing and proposed plans, elevations, site and block plans drawn to validation standard.
Construction and technical drawings
1:10 and 1:20 details for the parts of the job builders normally have to guess at.
Local watch-list
Trelights-specific issues we screen on the first visit.
Watch #1
Local Plan tests on isolated dwellings, plus lane access for plant and deliveries around Trelights
Who this is for
Straight facts about working with us here
- Design and build are offered from the same studio, which means the person answering your Trelights questions has seen the detail built.
- Applications for Trelights are handled through Cornwall Council, with Bodmin the nearest planning office we deal with regularly.
- Drawings, planning and building regulations are all produced in-house, so a extension enquiry does not get passed between firms.
Planning rules change and every site is different. For the final position on your address, check with Cornwall Council as the local planning authority or the Planning Portal.
What 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.
Quick check
Want a straight answer on whether your Trelights project is worth pursuing?
Send a few details — we'll come back within 1 working day with a plain-English view on planning risk, likely cost band and whether it's a project we'd take on.
Free · No obligation
Get a free feasibility view
For projects in Trelights and the PL29 area.
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.
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.
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.
- We live in the house. Can a extension in Trelights be done while we stay put?
- Usually yes for single-storey and rear work, with a temporary kitchen or bathroom arrangement agreed before the start. Whole-house remodels and roof work in Trelights are often easier if you move out for a few weeks. We set that expectation at feasibility stage rather than halfway through.
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 →Keep reading
Where to go next from Trelights
Trelights is covered from our Port Isaac run. Being a smaller place, the local detail matters more than the headline policy: lane access, neighbour proximity and what the immediate street already looks like.
Other services in Trelights
Nearby places we cover
A Trelights extension can be bought in stages, and most clients decide the build route after feasibility. For the final position on any address, Cornwall Council or the Planning Portal is the place to confirm it.
Ready to discuss your project in Trelights? We are on the A39 regularly.
Free · No obligation
Book a free visit in Trelights
No obligation. Reply usually same working day.