North Cornwall · PL28
Design, planning and build for Trevone 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. What works on a PL28 plot rarely works elsewhere — Trevone is a holiday-coast settlement in the PL28 area, with strong second-home demand and exposed coastal building conditions, with a building stock that leans toward detached houses and second homes.
Trevone sits in North Cornwall — covering PL28 from Padstow, St Eval, Harlyn outward.
- Cornwall AONB
- Coastal exposure zone
- ✓ Plain-English feasibility before any drawings
- ✓ Same team on paper as on site
- ✓ Fixed-fee planning packages, no surprise invoices
- ✓ Measured-survey accuracy from day one
Local proof — We typically have one or two extension jobs live in the PL28 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewLocal context
Why Trevone is its own job.
Cornwall Council's lens on Trevone is consistent: planning scrutiny often focuses on visual impact, occupancy, parking, overlooking and whether replacement buildings respect the coastal edge. For extension specifically, the surrounding landscape falls inside the Cornwall Area of Outstanding Natural Beauty, so massing, height and landscape impact carry extra weight in any planning decision; coastal salt-laden air around Trevone drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. That's why we treat every Trevone project as a PL28-area job first — not a generic Cornwall job with a postcode bolted on. The detached houses that dominate Trevone (and continue out toward Harlyn) 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 Trevone.
01
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
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
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
Our process
How a Trevone 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 a North Cornwall studio is the right fit for Trevone extension.
Building stock
Across Trevone (PL28) we work on coastal bungalows, holiday lets, second homes, detached houses, replacement dwellings. Each stock type drives a different extension response — detached houses in particular needs careful detailing here.
Parish & policy
Trevone sits in the parish of Trevone, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL28 from our studio, with regular extension jobs also running in Padstow, St Eval, Harlyn. Most Trevone site visits get booked within the same week.
How quickly can you visit a Trevone site?
Usually within the same week. Trevone (PL28) is on our regular North Cornwall run, alongside Padstow, St Eval, Harlyn. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitFAQs
Trevone 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 Trevone specifically, we'd start by checking AONB landscape sensitivity 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.
- 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.
- 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.
Trevone is part of Padstow
Trevone sits inside the Padstow catchment — we cover both as one extension territory.
See Extensions in Padstow →Other services in Trevone
Nearby places we cover
Designing a extension in Trevone is as much about reading the parish as reading the brief; we do both, and the planning outcomes follow.