Mid Cornwall · TR1 · Cornwall Council Central
House Extensions in Truro
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 Truro version of this work has its own character — Truro is Cornwall's only city, the county town and home to Cornwall Council itself, with a Georgian core, three-spired cathedral and Lemon Quay at its centre, with a building stock that leans toward modern development at West Langarth and Victorian terraces in Hendra and Highertown.
Truro sits in Mid Cornwall — just off the A390; covering TR1 from Threemilestone, Shortlanesend outward.
- Conservation Area
- ✓ Same team on paper as on site
- ✓ Fixed-fee planning packages, no surprise invoices
- ✓ Measured-survey accuracy from day one
- ✓ One studio — design, planning and build under one roof
Our process
How a Truro 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 TR1 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 Truro.
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
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
04
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
Local context
Why Truro is its own job.
The Truro Conservation Area covers a wide central zone including Lemon Street, the cathedral precinct and the river frontage. As the home of Cornwall Council planning, it tends to set the tone for design expectations across the county. For extension specifically, parts of Truro sit within a designated Conservation Area, which means materials, fenestration and roof pitches all need to read sympathetically with the existing streetscape. So every Truro job runs as a TR1-specific piece of work — local policy, local fabric, local builders. Most of our extension work in Truro lands on modern development at West Langarth, with detailing that has to nod to the wider Shortlanesend 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.
Local watch-list
Truro-specific issues we screen on the first visit.
Watch #1
Cathedral views safeguarded across central wards
Watch #2
Steep slopes around Lemon Street complicating basement and lower-ground options
Watch #3
Article 4 in the central Conservation Area
Watch #4
Flood Zone catchment along the river corridor
Truro is the hub for these neighbourhoods
We run extensions across Truro and the surrounding TR1 neighbourhoods — same studio, same site team.
Local fabric
One TR1 studio, one extension job — start to finish.
Building stock
Across Truro (TR1) we work on Georgian townhouses on Lemon Street, Victorian terraces in Hendra and Highertown, Edwardian villas, 1960s estates, modern development at West Langarth. Each stock type drives a different extension response — modern development at West Langarth in particular needs careful detailing here.
Parish & policy
Truro is its own city in Mid Cornwall, with planning history that's specific to the TR1 catchment.
Coverage
We cover TR1 from our studio, with regular extension jobs also running in Threemilestone, Shortlanesend, Playing Place. Most Truro site visits get booked within the same week.
Do you work in Truro regularly?
Yes — Truro and the wider TR1 catchment are core territory. We're typically on a Mid Cornwall site at least once a week, so logistics are baked in, not bolted on.
Request a free visitRecent work nearby
Recent professional-services HQ retrofit on Lemon Street ran as a Conservation Area application with internal-only listed sign-off.
See more recent Mid Cornwall work →Who this is for
In Truro the extension brief is almost always a private homeowner improving a forever home — so we lead with feasibility and long-term value, not show-home rhetoric.
FAQs
Truro Extensions — local questions answered.
- How much does an extension cost in Truro?
- 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. In Truro specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- 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.
- 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.
Other services in Truro
Nearby places we cover
Local neighbourhoods in Truro
If you're considering a extension project in the TR1 area, our deep understanding of Truro's architectural character can help navigate the process smoothly.