Mid Cornwall · PL24
House Extensions in Biscovey
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 Biscovey version of this work has its own character — Biscovey is a town-edge neighbourhood in the PL24 area, where modern housing, larger gardens and edge-of-settlement plots create practical development opportunities, with a building stock that leans toward infill plots and bungalows.
Biscovey sits in Mid Cornwall — covering PL24 from St Austell, Bugle, St Dennis outward.
- Rural / open-countryside policy area
- ✓ Fixed-fee planning packages, no surprise invoices
- ✓ Measured-survey accuracy from day one
- ✓ One studio — design, planning and build under one roof
- ✓ Local to Mid Cornwall — not a national franchise
Local watch-list
Common Biscovey pitfalls we plan around.
Watch #1
Tighter Local Plan tests on isolated rural dwellings
Who this is for
Biscovey 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 context
Why Biscovey is its own job.
Neighbour amenity, highways, drainage and the transition from built-up edge to countryside are usually the planning pressure points. 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. So every Biscovey job runs as a PL24-specific piece of work — local policy, local fabric, local builders. Most of our extension work in Biscovey lands on infill plots, with detailing that has to nod to the wider Bugle streetscape.
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 Biscovey.
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
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 Biscovey 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.
FAQs
Biscovey 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 Biscovey 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.
Biscovey is part of St Austell
Biscovey sits inside the St Austell catchment — we cover both as one extension territory.
See Extensions in St Austell →Local proof — We typically have one or two extension jobs live in the PL24 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewOther services in Biscovey
Nearby places we cover
If you're considering a extension project in the PL24 area, our deep understanding of Biscovey's architectural character can help navigate the process smoothly.