Mid Cornwall · TR3
Extensions for Baldhu (TR3)
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. Baldhu sits in Mid Cornwall, and that geography ends up in the drawings — Baldhu is a former mining settlement in the TR3 area, with granite terraces, chapel buildings and industrial landscape character still visible, with a building stock that leans toward post-war estates and granite terraces.
Baldhu sits in Mid Cornwall — covering TR3 from Truro, St Michael Penkivel, Calenick outward.
- Cornish Mining World Heritage Site
- Rural / open-countryside policy area
- ✓ Local to Mid Cornwall — not a national franchise
- ✓ Same team on paper as on site
- ✓ One studio — design, planning and build under one roof
- ✓ 30+ years of Cornwall Council approvals
Our process
How a Baldhu 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 TR3 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 Baldhu.
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 Baldhu is its own job.
In Baldhu the planning picture is specific: mining heritage, old plot widths and traditional materials make proportion and detailing more important than generic extension templates. For extension specifically, the wider area forms part of the Cornish Mining World Heritage Site, which adds a heritage assessment layer to most material changes; 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. That local reading is what makes a Baldhu (TR3) project different from a generic Cornwall scheme — and is the whole reason we work this way. On post-war estates in particular — the kind you'll also find toward Malpas — 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
Local snags worth knowing before drawing a Baldhu extension.
Watch #1
World Heritage Site assessment on changes visible in the mining landscape
Watch #2
Tighter Local Plan tests on isolated rural dwellings
Baldhu is part of Truro
Baldhu sits inside the Truro catchment — we cover both as one extension territory.
See Extensions in Truro →Local fabric
What sets a Baldhu extension brief apart.
Building stock
Across Baldhu (TR3) we work on miners cottages, granite terraces, chapel conversions, workers cottages, post-war estates. Each stock type drives a different extension response — post-war estates in particular needs careful detailing here.
Parish & policy
Baldhu sits in the parish of Baldhu, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR3 from our studio, with regular extension jobs also running in Truro, St Michael Penkivel, Calenick. Most Baldhu site visits get booked within the same week.
Can you handle both planning and build in Baldhu?
Yes — design, planning, building regs and full construction run under one roof. For clients with an existing Baldhu builder we can stop at a tender-ready Full Plans pack instead.
Request a free visitWho this is for
Baldhu 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
Baldhu 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 Baldhu 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.
- 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.
- 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.
Other services in Baldhu
Nearby places we cover
Every Baldhu extension we work on is treated as a TR3 job in its own right — local fabric, local policy, local builders.