Penwith · TR19 · Cornwall Council West
Design, planning and build for Trewellard loft conversion
A well-designed loft conversion adds a bedroom, an en-suite and useful storage to homes that were never built with the upper floor in mind — usually inside permitted development and almost always cheaper per square metre than extending sideways. Every Trewellard project we take on begins with reading the local context — Trewellard is a former mining settlement in the TR19 area, with granite terraces, chapel buildings and industrial landscape character still visible, with a building stock that leans toward chapel conversions and granite terraces.
Trewellard sits in Penwith — just off the A30; covering TR19 from Pendeen, Morvah, Lower Boscaswell outward.
- Cornwall AONB
- Cornish Mining World Heritage Site
- Rural / open-countryside policy area
- ✓30+ years of Cornwall Council approvals
- ✓Measured-survey accuracy from day one
- ✓One studio — design, planning and build under one roof
- ✓Local to Penwith — not a national franchise
Free · No obligation
Free Trewellard feasibility call
Tell us about your loft conversion. We reply within 1 working day — no obligation.
Local proof — Most Trewellard homeowners come to us after a loft conversion quote elsewhere felt vague on planning — we lead with feasibility instead.
Get a free feasibility viewLocal context
Why Trewellard is its own job.
Cornwall Council's lens on Trewellard is consistent: mining heritage, old plot widths and traditional materials make proportion and detailing more important than generic extension templates. For loft conversion 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; the wider area forms part of the Cornish Mining World Heritage Site, which adds a heritage assessment layer to most material changes; 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 Trewellard project as a TR19-area job first — not a generic Cornwall job with a postcode bolted on. The chapel conversions that dominate Trewellard (and continue out toward Lower Boscaswell) set the tone for any loft conversion scheme here.
Planning note
Most Cornish loft conversions are permitted development — but a Certificate of Lawfulness is worth the extra week and small fee for resale protection.
What we focus on
Loft Conversions considerations specific to Trewellard.
01
Stairs eat space — a loft conversion lives or dies by where the new staircase lands and what it costs you on the floor below.
02
Permitted development volume allowances are 40 cubic metres on a terrace and 50 on a detached or semi — but rear dormers in Conservation Areas often need full planning.
03
Building regs require minimum 2.0 metre headroom over the stairs and 30-minute fire protection on the existing stair enclosure — both shape the design.
04
Cornish slate roofs come in a huge range of pitches — anything below a 30° pitch struggles to give usable headroom without raising the ridge.
Page purpose
Drawings only, or drawings through to handover in Trewellard?
Both routes are open on a TR19 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Trewellard 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 TR19 scope, not as one opaque figure
Scope
Where our work starts and stops on a TR19 project
These stages can be bought separately. Most TR19 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 loft conversion enquiry does not get passed between firms.
- Design and build are offered from the same studio, which means the person answering your Trewellard 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 TR19 pages
Trewellard 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 Trewellard loft conversion project runs.
Step 1
Feasibility
Roof, headroom, stair landing and structural assessment.
Step 2
Design
Layout options that respect the staircase, headroom and bathroom positioning.
Step 3
Approvals
Planning or permitted development confirmation, plus building regs.
Step 4
Build
Sequenced to keep the family living downstairs throughout most of the work.
Step 5
Handover
Finish, snag, certify, hand over the keys.
Loft conversions typically run six to eighteen weeks on site depending on type, with four to eight weeks of design and approvals beforehand.
Quick check
Want a straight answer on whether your Trewellard 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.
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Get a free feasibility view
For projects in Trewellard and the TR19 area.
Local fabric
Choosing a loft conversion team that actually knows TR19.
Building stock
Across Trewellard (TR19) we work on miners cottages, granite terraces, chapel conversions, workers cottages, post-war estates. Each stock type drives a different loft conversion response — chapel conversions in particular needs careful detailing here.
Parish & policy
Trewellard sits in the parish of Trewellard, which matters for how parish-level consultation lands on a loft conversion application.
Coverage
We cover TR19 from our studio, with regular loft conversion jobs also running in Pendeen, Morvah, Lower Boscaswell. Most Trewellard site visits get booked within the same week.
How quickly can you visit a Trewellard site?
Usually within the same week. Trewellard (TR19) is on our regular Penwith run, alongside Pendeen, Morvah, Lower Boscaswell. First visits are free and you'll get an honest feasibility view inside seven days.
Request a free visitFAQs
Trewellard Loft Conversions — local questions answered.
- Do I need planning permission for a loft conversion?
- Often no — most loft conversions sit inside permitted development on a typical Cornish house. Conservation Areas, AONB and properties on principal elevations need full planning, and we'll confirm at first review. In Trewellard specifically, we'd start by checking AONB landscape sensitivity before committing to a direction.
- Can I live downstairs while it's built?
- Yes — most loft conversions are built with the family staying in the house. There'll be a couple of disruptive days when the staircase comes through, but the bulk of the work is upstairs.
- Will I have enough headroom?
- We need a minimum 2.2 metres ridge-to-joist before alterations to make a usable conversion straightforward. Less than that and we'd consider raising the ridge, which is a planning conversation, not a permitted development one.
- Will it add value?
- An extra bedroom and bathroom typically adds noticeably more value than the build cost in most Cornish markets — but the value matters less than the daily use you'll get from the space.
- We live in the house. Can a loft conversion in Trewellard 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 Trewellard are often easier if you move out for a few weeks. We set that expectation at feasibility stage rather than halfway through.
- How much does a loft conversion cost?
- A simple Velux conversion starts around £30,000 in Cornwall; a rear dormer with en-suite typically runs £45,000 to £65,000; hip-to-gable and mansards more. Stair location and bathroom complexity drive most of the cost.
Trewellard is part of Pendeen
Trewellard sits inside the Pendeen catchment — we cover both as one loft conversion territory.
See Loft Conversions in Pendeen →Other services in Trewellard
Nearby places we cover
The loft conversion jobs we're proudest of in Trewellard are the ones where the planning route was clear before a single elevation was drawn. Parish-level consultation in Trewellard is worth planning for, not reacting to.
Book a site visit in the TR19 area Truro handles the planning end for TR19.
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Book a free visit in Trewellard
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