West Cornwall · TR20
One studio for extension in Long Rock
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 Long Rock starts with a measured walk-round — Long Rock is a coastal village on Mounts Bay between Penzance and Marazion, much expanded by twentieth-century development along the A30 and railway corridor, with a building stock that leans toward converted railway-era buildings and post-war estates.
Long Rock sits in West Cornwall — covering TR20 from Marazion, Penzance, Gulval outward.
- Coastal exposure zone
- ✓ Local to West Cornwall — not a national franchise
- ✓ Same team on paper as on site
- ✓ Measured-survey accuracy from day one
- ✓ One studio — design, planning and build under one roof
Our process
How a Long Rock 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 — Our West Cornwall workload means a Long Rock extension project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewWhat we focus on
Extensions considerations specific to Long Rock.
01
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.
02
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
03
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
04
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
Local context
Why Long Rock is its own job.
Two things shape a Long Rock application: parish character and policy. On policy — outside Conservation Area and AONB but the seafront is environmentally sensitive; flood zone constraints affect properties south of the railway line. Ludgvan parish policy applies. For extension specifically, coastal salt-laden air around Long Rock 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 Long Rock programme tends to run on time. On converted railway-era buildings in particular — the kind you'll also find toward Marazion — 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 TR20 constraints that shape a extension brief.
Watch #1
Coastal exposure driving fixing, render and joinery spec
Long Rock is part of Marazion
Long Rock sits inside the Marazion catchment — we cover both as one extension territory.
See Extensions in Marazion →Local fabric
One TR20 studio, one extension job — start to finish.
Building stock
Across Long Rock (TR20) we work on 1930s seafront bungalows, post-war estates, modern Persimmon-style estates inland, converted railway-era buildings. Each stock type drives a different extension response — converted railway-era buildings in particular needs careful detailing here.
Parish & policy
Long Rock sits in the parish of Ludgvan, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR20 from our studio, with regular extension jobs also running in Marazion, Penzance, Gulval. Most Long Rock site visits get booked within the same week.
Can you handle both planning and build in Long Rock?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing Long Rock builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
Long Rock 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
Long Rock Extensions — local questions answered.
- 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. In Long Rock specifically, we'd start by checking the latest parish-level planning history before committing to a direction.
- 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.
- 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.
- 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 Long Rock
Nearby places we cover
The TR20 stretch of West Cornwall has its own rhythm; our extension work respects it, and Cornwall Council usually responds in kind.