North Cornwall · TR5
Trevellas loft conversions — a North Cornwall studio
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. Anchor any Trevellas loft conversion in the local fabric and the rest follows — Trevellas is a coastal village in the TR5 area, where sea exposure, views and seasonal pressure shape most building decisions, with a building stock that leans toward replacement dwellings and granite cottages.
Trevellas sits in North Cornwall — covering TR5 from St Agnes, Mount Hawke, Mithian outward.
- Cornwall AONB
- Cornish Mining World Heritage Site
- Coastal exposure zone
- ✓ Plain-English feasibility before any drawings
- ✓ 30+ years of Cornwall Council approvals
- ✓ Free first site visit, no obligation
- ✓ One studio — design, planning and build under one roof
Who this is for
Trevellas runs the full mix — owner-occupier, holiday-let, commercial and the occasional smallholding — so we scope every loft conversion enquiry from the use-class up.
Local watch-list
What usually catches loft conversion projects out in Trevellas.
Watch #1
AONB landscape-impact scrutiny on visible elevations
Watch #2
World Heritage Site assessment on changes visible in the mining landscape
Watch #3
Coastal exposure driving fixing, render and joinery spec
Local proof — We typically have one or two loft conversion jobs live in the TR5 area at any time, so the local planning officers know our drawings on sight.
Get a free feasibility viewFAQs
Trevellas 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 Trevellas specifically, we'd start by checking AONB landscape sensitivity before committing to a direction.
- 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.
- 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.
- How long does a loft conversion take?
- Allow six to ten weeks on site for a Velux conversion, eight to fourteen weeks for a dormer, twelve to eighteen weeks for hip-to-gable. Add four to eight weeks for design and regs beforehand.
Local context
Why Trevellas is its own job.
The planning backdrop in North Cornwall is real, not abstract: coastal setting and landscape sensitivity mean rooflines, glazing, drainage and external materials need careful handling from the first sketch. 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; coastal salt-laden air around Trevellas drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. Treat the TR5 parish brief as the design brief and the Trevellas application has somewhere to land. Whether the project is on replacement dwellings in the centre or further out toward St Agnes, the loft conversion response is locally tuned.
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 Trevellas.
01
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.
02
Stairs eat space — a loft conversion lives or dies by where the new staircase lands and what it costs you on the floor below.
03
Cornish slate roofs come in a huge range of pitches — anything below a 30° pitch struggles to give usable headroom without raising the ridge.
04
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.
Our process
How a Trevellas 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.
Local fabric
Why a North Cornwall studio is the right fit for Trevellas loft conversion.
Building stock
Across Trevellas (TR5) we work on granite cottages, rendered coastal houses, holiday homes, bungalows, replacement dwellings. Each stock type drives a different loft conversion response — replacement dwellings in particular needs careful detailing here.
Parish & policy
Trevellas sits in the parish of Trevellas, which matters for how parish-level consultation lands on a loft conversion application.
Coverage
We cover TR5 from our studio, with regular loft conversion jobs also running in St Agnes, Mount Hawke, Mithian. Most Trevellas site visits get booked within the same week.
What does a first Trevellas consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR5 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitTrevellas is part of St Agnes
Trevellas sits inside the St Agnes catchment — we cover both as one loft conversion territory.
See Loft Conversions in St Agnes →Other services in Trevellas
Nearby places we cover
A loft conversion in Trevellas stands or falls on how well it reads the street — we treat that as the design brief, not an afterthought.