South Cornwall · PL26
House Extensions in Mevagissey
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 Mevagissey, that work is shaped by the place itself — Mevagissey is a working fishing port south of St Austell, with the second-busiest fishing fleet in Cornwall and an exceptionally dense Conservation Area of slate-hung cottages around its inner and outer harbours, with a building stock that leans toward slate-hung fishermen's cottages and Victorian terraces above the harbour.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
Local context
Why Mevagissey is its own job.
Conservation Area covers the entire historic harbour area; AONB across most of the parish. Slate-hung walls and traditional sash windows are the design baseline; modern alterations face high scrutiny. For extension specifically, parts of Mevagissey 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 Mevagissey drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. That's why we treat every Mevagissey project as a PL26-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 Mevagissey.
01
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
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
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
Our process
How a Mevagissey 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.
FAQs
Mevagissey Extensions — common questions.
- 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. In Mevagissey specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- 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.
Other services in Mevagissey
Nearby places we cover