Mid Cornwall · TR14 · Cornwall Council West
Single storey extension costs in Camborne, and what actually moves the number
A single storey rear or side extension is the most common brief we take in Camborne, and the cost gap between two apparently identical projects usually comes down to four things: how the ground behaves once it is opened up, how much glazing is in the rear elevation, whether the kitchen is being reworked at the same time, and how the new roof meets the existing one, which is where the awkward detailing lives. 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 Camborne, that work is shaped by the place itself — Camborne is one of the great Cornish mining towns, twinned with Redruth as the engine of the Cornish Mining World Heritage Site, with a strong terraced street pattern and surviving engine houses on its outskirts, with a building stock that leans toward post-war social housing estates and Victorian terraces.
Camborne sits in Mid Cornwall — just off the A30; with Truro the closest city; 4 miles from Redruth.
- Conservation Area
- Cornish Mining World Heritage Site
- ✓Cost banded feasibility before any design fee is committed
- ✓Camborne ground and access assessed on the first visit
- ✓Drawings and build from one studio, so the detail is priced not guessed
- ✓Free first consultation across Mid Cornwall
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Free Camborne feasibility call
Tell us about your extension. We reply within 1 working day — no obligation.
Who this is for
In Camborne 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.
Local watch-list
Common Camborne pitfalls we plan around.
Watch #1
Mining-related ground risk on south-of-town sites
Watch #2
World Heritage Site landscape sensitivity
Watch #3
Tight terraced frontages with no flank access
Watch #4
Older Cornish unit construction needing thermal upgrade strategy
Local proof — Our Mid Cornwall workload means a Camborne extension project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewFAQs
Camborne Extensions — local questions answered.
- What drives the cost of a single storey extension in Camborne?
- Ground conditions, glazing area, structural openings into the existing house, drainage runs and access for materials. In Camborne (TR14) access is often the quiet one, because a site a lorry cannot reach is a site where everything is handled twice.
- Is a rate per square metre reliable?
- Only as a sanity check. Two extensions of the same size can differ by a third once you change the glazing spec, the roof form and the amount of existing structure being altered. We price from drawings, not from a rate.
- Does using one studio for drawings and build change the cost?
- It changes where the cost is certain. Because we draw the scheme and then build it, the detail that a separate builder would price as a risk is already resolved on paper, so there is less contingency priced into the unknowns.
- What is the cheapest way to add space in Camborne?
- Usually reworking what already exists before extending: a garage conversion, a rethought internal layout, or a smaller extension that unlocks a better plan. We will say so if that is the better answer for your house, even though it is a smaller job for us.
- 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. In Camborne specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- We live in the house. Can an extension in Camborne be done while we stay put?
- Usually yes for single-storey and rear work, with a temporary kitchen or bathroom arrangement agreed before the start. Whole-house remodels and roof work in Camborne are often easier if you move out for a few weeks. We set that expectation at feasibility stage rather than halfway through.
Quick check
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Send a few details — we'll come back within 1 working day with a plain-English view on planning risk, likely cost band and whether it's a project we'd take on.
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Get a free feasibility view
For projects in Camborne and the TR14 area.
Scope
What we can draw, survey and build around Camborne
These stages can be bought separately. Most TR14 projects use three of them.
Structural coordination
Calculations coordinated with the drawings so building control sees one consistent story.
Construction and technical drawings
1:10 and 1:20 details for the parts of the job builders normally have to guess at.
Planning application drawings
Existing and proposed plans, elevations, site and block plans drawn to validation standard.
Commercial drawings
Change of use, fit-out and access documentation for Class E and mixed-use premises.
Measured survey
An accurate record of what is actually there, which is where most avoidable cost is removed.
Page purpose
Drawings only, or drawings through to handover in Camborne?
Both routes are open on a TR14 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Camborne clients take the drawings, tender them locally, then come back to us for the build if the numbers do not stack up.
- Route one: feasibility, planning and a tender-ready technical pack
- Route two: the same pack, then the build under one contract
- Either way the survey and feasibility work is identical, so the decision can wait
- Fees quoted per stage against the TR14 scope, not as one opaque figure
Keep reading
Follow the chain: survey, drawings, build
We cover Camborne and the wider TR14 district directly, typically alongside jobs in Redruth. Extensions enquiries here are common enough that we know the constraints before the first visit.
Who this is for
Why this page exists, and who it is for
- Designated-area work is routine here, so heritage and landscape statements are produced alongside the drawings rather than outsourced.
- Sites we know on the ground here include the area around Trevithick Square and Cross Street.
- Drawings, planning and building regulations are all produced in-house, so an extension enquiry does not get passed between firms.
- Applications for Camborne are handled through Cornwall Council, with Truro the nearest planning office we deal with regularly.
Planning rules change and every site is different. For the final position on your address, check with Cornwall Council as the local planning authority or the Planning Portal.
Local context
Why Camborne is its own job.
Locally, camborne sits within the World Heritage Site buffer; mining heritage features are protected and design statements need to address industrial character. Trevithick Road, Cross Street and the Conservation Area carry tighter material expectations. For extension specifically, parts of Camborne 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 Camborne projects parish-up, not template-down — the TR14 context shapes the design from day one. Whether the project is on post-war social housing estates in the centre or further out toward Redruth, the extension response is locally tuned. Historic fabric changes the sequence: survey first, then design around what the building can take. Consent routes for listed buildings sit separately from ordinary planning, so treat any general guidance here as a starting point and check with Cornwall Council.
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.
Recent work nearby
Pool industrial-to-residential change-of-use last year hit Full Plans first time.
See more recent Mid Cornwall work →What we focus on
Extensions considerations specific to Camborne.
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
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
Our process
How a Camborne 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 a Mid Cornwall studio is the right fit for Camborne extension.
Building stock
Across Camborne (TR14) we work on miners' cottages, Victorian terraces, Wesleyan-era chapels and conversions, post-war social housing estates, modern development at Tuckingmill. Each stock type drives a different extension response — post-war social housing estates in particular needs careful detailing here.
Parish & policy
Camborne is its own town in Mid Cornwall, with planning history that's specific to the TR14 catchment.
Coverage
We cover TR14 from our studio, with regular extension jobs also running in Redruth. Most Camborne site visits get booked within the same week.
What does a first Camborne consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR14 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitOther services in Camborne
Nearby places we cover
The honest answer for Camborne is that a rate per square metre is a starting point, not a price. We give you a cost band at feasibility stage, then a real figure once the drawings exist and the work can be priced properly.
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