West Cornwall · TR17 · Cornwall Council West
Extending a period terrace in Marazion — side-return, rear and infill
Marazion's late-Victorian and Edwardian terraces share a predictable trio of headaches: the side-return dogleg, a chimney breast nobody wants to keep, and party walls to two neighbours. On TR17 stock we detail the roof junction, the flank cavity and the party-wall notices before drawings go anywhere near planning. 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. Anchor any Marazion extension in the local fabric and the rest follows — Marazion sits opposite St Michael's Mount across a tidal causeway and is one of Cornwall's oldest chartered towns, designated AONB for its setting, with a building stock that leans toward Georgian seafront houses and Victorian villas.
Marazion sits in West Cornwall — just off the A30; with Truro the closest city; 3 miles from Penzance.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
- ✓Side-return infill: typical £48k–£75k on a Marazion 2-bed terrace
- ✓Full-width rear + side return: £75k–£120k
- ✓Party wall notices handled in-house
- ✓Chimney-breast removal + gallows detailing coordinated with SE
Free · No obligation
Free Marazion feasibility call
Tell us about your extension. We reply within 1 working day — no obligation.
Local proof — Our West Cornwall workload means a Marazion extension project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewLocal context
Why Marazion is its own job.
The planning backdrop in West Cornwall is real, not abstract: the whole town centre is within the Conservation Area and the AONB; views to and from St Michael's Mount are a material planning consideration on most schemes. Roof pitches, ridge heights and seaward elevations are tightly controlled. For extension specifically, parts of Marazion 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 Marazion drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. Treat the TR17 parish brief as the design brief and the Marazion application has somewhere to land. Whether the project is on Georgian seafront houses in the centre or further out toward Goldsithney, the extension response is locally tuned.
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 Marazion.
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
Wind and sea-spray exposure can drive material choices on west-facing extensions; we detail accordingly.
03
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
04
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.
Our process
How a Marazion 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.
Quick check
Want a straight answer on whether your Marazion project is worth pursuing?
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.
Free · No obligation
Get a free feasibility view
For projects in Marazion and the TR17 area.
Local fabric
Choosing a extension team that actually knows TR17.
Building stock
Across Marazion (TR17) we work on granite cottages, Georgian seafront houses, Victorian villas, 1960s bungalows on Green Lane, modern coastal builds. Each stock type drives a different extension response — Georgian seafront houses in particular needs careful detailing here.
Parish & policy
Marazion is its own town in West Cornwall, with planning history that's specific to the TR17 catchment.
Coverage
We cover TR17 from our studio, with regular extension jobs also running in Penzance, Goldsithney, Perranuthnoe. Most Marazion site visits get booked within the same week.
What does a first Marazion consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR17 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitRecent work nearby
Behind-the-Square cottage we extended last winter used a slim glazed link to keep the original roof intact.
See more recent West Cornwall work →FAQs
Marazion Extensions — local questions answered.
- Do I need a party wall agreement for a side-return in Marazion?
- Almost always yes — cutting into the flank wall or excavating within 3m of the neighbouring foundation triggers the Party Wall etc. Act 1996. We serve notices at RIBA Stage 3 so consent lands before tender.
- Can I remove the chimney breast during a Marazion rear extension?
- Yes, but the stack above needs propping (usually a gallows bracket or steel) and a structural engineer's calc. On listed or Conservation Area terraces the stack usually has to stay externally even if the breast goes.
- How do you stop the extension looking bolted-on to a period terrace?
- Match the eaves line, keep the ridge subservient, and either contrast honestly (zinc/glass) or match brick+lime mortar. The worst outcome is a half-hearted "matching" brick that ages differently.
- 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. In Marazion specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- 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.
- 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.
Marazion is the hub for these neighbourhoods
We run extensions across Marazion and the surrounding TR17 neighbourhoods — same studio, same site team.
- Perranuthnoe
TR20
- Goldsithney
TR20
- Long Rock
TR20
Other services in Marazion
Nearby places we cover
Local neighbourhoods in Marazion
A Marazion terrace extension lives or dies on three details: the party-wall route, the flashing at the original rear-slope junction, and how the new kitchen ceiling meets the retained chimney breast. Get those right at design stage and the build is calm.
Book a period-terrace feasibility visit in Marazion
Free · No obligation
Book a free visit in Marazion
No obligation. Reply usually same working day.