Mid Cornwall · TR1
Highertown extensions — a Mid Cornwall studio
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. On a Highertown site, the brief always meets the place — Highertown is a town-edge neighbourhood in the TR1 area, where modern housing, larger gardens and edge-of-settlement plots create practical development opportunities, with a building stock that leans toward bungalows and detached houses.
Highertown sits in Mid Cornwall — covering TR1 from Truro, St Michael Penkivel, Calenick outward.
- Conservation Area
- ✓ Conservation Area experience built into the fee
- ✓ Cornwall Council regulars across every sub-area
- ✓ Measured-survey accuracy from day one
- ✓ One studio — design, planning and build under one roof
Who this is for
Highertown 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 TR1 constraints that shape a extension brief.
Watch #1
Conservation Area material and fenestration controls in central Highertown
Local proof — We typically have one or two extension jobs live in the TR1 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewFAQs
Highertown Extensions — local questions answered.
- 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. In Highertown 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.
- 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 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.
Local context
Why Highertown is its own job.
The planning backdrop in Mid Cornwall is real, not abstract: neighbour amenity, highways, drainage and the transition from built-up edge to countryside are usually the planning pressure points. For extension specifically, parts of Highertown sit within a designated Conservation Area, which means materials, fenestration and roof pitches all need to read sympathetically with the existing streetscape. Treat the TR1 parish brief as the design brief and the Highertown application has somewhere to land. Whether the project is on bungalows in the centre or further out toward Truro, 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 Highertown.
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
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
03
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
04
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.
Our process
How a Highertown 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 Highertown homeowners pick a local studio for extension.
Building stock
Across Highertown (TR1) we work on modern estates, bungalows, semis, detached houses, infill plots. Each stock type drives a different extension response — bungalows in particular needs careful detailing here.
Parish & policy
Highertown sits in the parish of Highertown, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR1 from our studio, with regular extension jobs also running in Truro, St Michael Penkivel, Calenick. Most Highertown site visits get booked within the same week.
What does a first Highertown consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR1 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitHighertown is part of Truro
Highertown sits inside the Truro catchment — we cover both as one extension territory.
See Extensions in Truro →Other services in Highertown
Nearby places we cover
From initial feasibility to final handover, we manage extension projects across Highertown with careful attention to what makes Mid Cornwall unique.