Penwith · TR20 · Cornwall Council West
Design, planning and build for Morvah extension
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. A TR20 site visit comes before a Morvah sketch, every time — Morvah is a moorland-edge hamlet in the TR20 area, where exposed weather, narrow lanes and rural character set the brief, with a building stock that leans toward converted barns and isolated houses.
Morvah sits in Penwith — just off the A30; covering TR20 from Pendeen, Trewellard, Lower Boscaswell outward.
- Cornwall AONB
- Rural / open-countryside policy area
- ✓Cornwall Council West sub-area regulars
- ✓Local to Penwith — not a national franchise
- ✓Same team on paper as on site
- ✓Fixed-fee planning packages, no surprise invoices
Free · No obligation
Free Morvah feasibility call
Tell us about your extension. We reply within 1 working day — no obligation.
Local proof — We typically have one or two extension jobs live in the TR20 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewLocal context
Why Morvah is its own job.
Cornwall Council's lens on Morvah is consistent: rural policy, landscape impact and services such as drainage are usually the key constraints, especially outside settlement boundaries. For extension specifically, 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; 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 Morvah project as a TR20-area job first — not a generic Cornwall job with a postcode bolted on. The converted barns that dominate Morvah (and continue out toward Lower Boscaswell) set the tone for any extension scheme here.
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 Morvah.
01
Cornish granite and slate-hung walls react differently to new openings than modern brickwork — lintel choice and structural sequencing matter.
02
Drainage on older Cornish properties is rarely on a clean modern map; CCTV survey before design is often money well spent.
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.
Page purpose
Drawings only, or drawings through to handover in Morvah?
Both routes are open on a TR20 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Morvah 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 TR20 scope, not as one opaque figure
Scope
Where our work starts and stops on a TR20 project
These stages can be bought separately. Most TR20 projects use three of them.
Building regulation drawings
Full Plans sets with sections, construction notes and coordinated structural information.
Structural coordination
Calculations coordinated with the drawings so building control sees one consistent story.
Measured survey
An accurate record of what is actually there, which is where most avoidable cost is removed.
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.
Who this is for
Our footing in Penwith
- Designated-area work is routine here, so heritage and landscape statements are produced alongside the drawings rather than outsourced.
- Drawings, planning and building regulations are all produced in-house, so a extension enquiry does not get passed between firms.
- Design and build are offered from the same studio, which means the person answering your Morvah questions has seen the detail built.
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.
Keep reading
Related TR20 pages
Morvah is covered from our Pendeen run. Being a smaller place, the local detail matters more than the headline policy: lane access, neighbour proximity and what the immediate street already looks like.
Our process
How a Morvah 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 Morvah 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 Morvah and the TR20 area.
Local fabric
Why a Penwith studio is the right fit for Morvah extension.
Building stock
Across Morvah (TR20) we work on stone cottages, farm buildings, isolated houses, converted barns, small rural infill. Each stock type drives a different extension response — converted barns in particular needs careful detailing here.
Parish & policy
Morvah sits in the parish of Morvah, which matters for how parish-level consultation lands on a extension application.
Coverage
We cover TR20 from our studio, with regular extension jobs also running in Pendeen, Trewellard, Lower Boscaswell. Most Morvah site visits get booked within the same week.
How quickly can you visit a Morvah site?
Usually within the same week. Morvah (TR20) is on our regular Penwith run, alongside Pendeen, Trewellard, Lower Boscaswell. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitFAQs
Morvah Extensions — local questions answered.
- We live in the house. Can a extension in Morvah 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 Morvah are often easier if you move out for a few weeks. We set that expectation at feasibility stage rather than halfway through.
- 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 Morvah specifically, we'd start by checking AONB landscape sensitivity before committing to a direction.
- 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.
- 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.
- 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.
Morvah is part of Pendeen
Morvah sits inside the Pendeen catchment — we cover both as one extension territory.
See Extensions in Pendeen →Other services in Morvah
Nearby places we cover
On a Morvah site the success of a extension is decided in week one — by reading the constraints right, not by drawing them away. For the final position on any address, Cornwall Council or the Planning Portal is the place to confirm it.
Book a site visit in the TR20 area Truro handles the planning end for TR20.
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Book a free visit in Morvah
No obligation. Reply usually same working day.