East Cornwall · PL17
One studio for extension in Harrowbarrow
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. Working in Harrowbarrow means starting from the PL17 context — Harrowbarrow is a commuter village in the PL17 area, with everyday family housing, edge-of-village plots and quick routes to its parent town, with a building stock that leans toward bungalows and older cottages.
Harrowbarrow sits in East Cornwall — covering PL17 from Callington, Stoke Climsland, Linkinhorne outward.
- Rural / open-countryside policy area
- ✓ One studio — design, planning and build under one roof
- ✓ Local to East Cornwall — not a national franchise
- ✓ Plain-English feasibility before any drawings
- ✓ Measured-survey accuracy from day one
Our process
How a Harrowbarrow 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 Harrowbarrow 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 Harrowbarrow.
01
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.
02
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.
03
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
04
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
Local context
Why Harrowbarrow is its own job.
Two things shape a Harrowbarrow application: parish character and policy. On policy — applications here usually turn on neighbour amenity, parking, overlooking and whether new work fits the rhythm of existing streets. 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. Get that local reading right and the rest of the Harrowbarrow programme tends to run on time. On bungalows in particular — the kind you'll also find toward Calstock — 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 Harrowbarrow.
Watch #1
Tighter Local Plan tests on isolated rural dwellings
Harrowbarrow is part of Callington
Harrowbarrow sits inside the Callington catchment — we cover both as one extension territory.
See Extensions in Callington →Local fabric
Harrowbarrow extensions — the local-studio difference.
Building stock
Across Harrowbarrow (PL17) we work on post-war semis, bungalows, modern estates, older cottages, garden infill plots. Each stock type drives a different extension response — bungalows in particular needs careful detailing here.
Parish & policy
Harrowbarrow sits in the parish of Harrowbarrow, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL17 from our studio, with regular extension jobs also running in Callington, Stoke Climsland, Linkinhorne. Most Harrowbarrow site visits get booked within the same week.
Can you handle both planning and build in Harrowbarrow?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing Harrowbarrow builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
Harrowbarrow 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
Harrowbarrow 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 Harrowbarrow 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 Harrowbarrow
Nearby places we cover
If you're balancing ambition against PL17 planning realism, our Harrowbarrow extension work threads that needle without the usual drama.