North Cornwall · PL28
One studio for extension in Harlyn
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 Harlyn starts with a measured walk-round — Harlyn 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 coastal bungalows and second homes.
Harlyn sits in North Cornwall — covering PL28 from Padstow, St Eval, Trevone outward.
- Cornwall AONB
- Coastal exposure zone
- ✓ Fixed-fee planning packages, no surprise invoices
- ✓ Measured-survey accuracy from day one
- ✓ AONB experience built into the fee
- ✓ Local to North Cornwall — not a national franchise
Our process
How a Harlyn 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 — 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 viewWhat we focus on
Extensions considerations specific to Harlyn.
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 Harlyn is its own job.
Two things shape a Harlyn application: parish character and policy. On policy — 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 Harlyn drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. Get that local reading right and the rest of the Harlyn programme tends to run on time. On coastal bungalows in particular — the kind you'll also find toward St Merryn — 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
What usually catches extension projects out in Harlyn.
Watch #1
AONB landscape-impact scrutiny on visible elevations
Watch #2
Coastal exposure driving fixing, render and joinery spec
Harlyn is part of Padstow
Harlyn sits inside the Padstow catchment — we cover both as one extension territory.
See Extensions in Padstow →Local fabric
What sets a Harlyn extension brief apart.
Building stock
Across Harlyn (PL28) we work on coastal bungalows, holiday lets, second homes, detached houses, replacement dwellings. Each stock type drives a different extension response — coastal bungalows in particular needs careful detailing here.
Parish & policy
Harlyn sits in the parish of Harlyn, 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, Trevone. Most Harlyn site visits get booked within the same week.
Can you handle both planning and build in Harlyn?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing Harlyn builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
Harlyn 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
Harlyn 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 Harlyn specifically, we'd start by checking AONB landscape sensitivity 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.
- 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.
Other services in Harlyn
Nearby places we cover
The PL28 stretch of North Cornwall has its own rhythm; our extension work respects it, and Cornwall Council usually responds in kind.