Mid Cornwall · TR14

House Extensions in Camborne

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 miners' cottages and Victorian terraces.

  • Conservation Area
  • Cornish Mining World Heritage Site

Local context

Why Camborne is its own job.

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. That's why we treat every Camborne project as a TR14-area job first — not a generic Cornwall job with a postcode bolted on.

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 Camborne.

  • 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

    Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.

  • 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 Camborne extension project runs.

  1. Step 1

    Brief

    We meet on site, talk through how you live now and what's missing from the current layout.

  2. Step 2

    Design

    Two or three sketch directions with rough budgets, then refinement of the chosen route.

  3. Step 3

    Approvals

    Planning or Cert of Lawfulness, then a full building regs package.

  4. Step 4

    Build

    Either through your own builder with our drawings, or as a full build by our team.

  5. 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

Camborne Extensions — common questions.

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.
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.

Planning a extension project in Camborne?

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