East Cornwall · PL18
Gunnislake extension — feasibility first, drawings second
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. In Gunnislake, that work is shaped by the place itself — Gunnislake is a former mining settlement in the PL18 area, with granite terraces, chapel buildings and industrial landscape character still visible, with a building stock that leans toward chapel conversions and miners cottages.
Gunnislake sits in East Cornwall — covering PL18 from Callington, Stoke Climsland, Linkinhorne outward.
- Conservation Area
- Cornish Mining World Heritage Site
- ✓ Plain-English feasibility before any drawings
- ✓ 30+ years of Cornwall Council approvals
- ✓ Conservation Area experience built into the fee
- ✓ Cornwall Council regulars across every sub-area
Who this is for
Gunnislake runs the full mix — owner-occupier, holiday-let, commercial and the occasional smallholding — so we scope every extension enquiry from the use-class up.
Local watch-list
The PL18 constraints that shape a extension brief.
Watch #1
Conservation Area material and fenestration controls in central Gunnislake
Watch #2
World Heritage Site assessment on changes visible in the mining landscape
Local proof — Most Gunnislake homeowners come to us after a extension quote elsewhere felt vague on planning — we lead with feasibility instead.
Get a free feasibility viewFAQs
Gunnislake 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 Gunnislake specifically, we'd start by checking the Conservation Area boundary 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.
- 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.
- 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.
Local context
Why Gunnislake is its own job.
Locally, mining heritage, old plot widths and traditional materials make proportion and detailing more important than generic extension templates. For extension specifically, parts of Gunnislake sit within a designated Conservation Area, which means materials, fenestration and roof pitches all need to read sympathetically with the existing streetscape; the wider area forms part of the Cornish Mining World Heritage Site, which adds a heritage assessment layer to most material changes. Which is why we scope Gunnislake projects parish-up, not template-down — the PL18 context shapes the design from day one. Whether the project is on chapel conversions in the centre or further out toward Callington, the extension response is locally tuned.
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 Gunnislake.
01
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
02
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
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
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.
Our process
How a Gunnislake 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 Gunnislake homeowners pick a local studio for extension.
Building stock
Across Gunnislake (PL18) we work on miners cottages, granite terraces, chapel conversions, workers cottages, post-war estates. Each stock type drives a different extension response — chapel conversions in particular needs careful detailing here.
Parish & policy
Gunnislake sits in the parish of Gunnislake, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover PL18 from our studio, with regular extension jobs also running in Callington, Stoke Climsland, Linkinhorne. Most Gunnislake site visits get booked within the same week.
What does a first Gunnislake consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a PL18 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitGunnislake is part of Callington
Gunnislake sits inside the Callington catchment — we cover both as one extension territory.
See Extensions in Callington →Other services in Gunnislake
Nearby places we cover
The extension jobs we're proudest of in Gunnislake are the ones where the planning route was clear before a single elevation was drawn.