South Cornwall · PL23

House Extensions in Polruan

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 Polruan, that work is shaped by the place itself — Polruan sits opposite Fowey across the river, accessible by passenger ferry, with a tightly packed slate-cottage village clinging to the cliffs above the harbour, with a building stock that leans toward slate-hung cottages and fishermen's terraces.

  • Conservation Area
  • Cornwall AONB
  • Coastal exposure zone
  • Rural / open-countryside policy area

Local context

Why Polruan is its own job.

Conservation Area covers the village core; AONB and Heritage Coast across Lanteglos parish. Cliff-edge sites face strict controls and access for any build is logistically tight. For extension specifically, parts of Polruan sit within a designated Conservation Area, which means materials, fenestration and roof pitches all need to read sympathetically with the existing streetscape; the surrounding landscape falls inside the Cornwall Area of Outstanding Natural Beauty, so massing, height and landscape impact carry extra weight in any planning decision; coastal salt-laden air around Polruan drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure; 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's why we treat every Polruan project as a PL23-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 Polruan.

  • 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

    Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.

  • 03

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

Our process

How a Polruan 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

Polruan 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 Polruan specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
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.
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.

Planning a extension project in Polruan?

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