Mid Cornwall · TR2

Loft Conversions in Tresillian

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. In Tresillian, that work is shaped by the place itself — Tresillian is a village east of Truro at the head of the Tresillian River, AONB-designated, with a Conservation Area covering the village core, with a building stock that leans toward traditional cob and granite cottages and Victorian villas.

  • Conservation Area
  • Cornwall AONB
  • Coastal exposure zone
  • Rural / open-countryside policy area

Local context

Why Tresillian is its own job.

Conservation Area covers the village; AONB across the parish. Riverside ecology and views shape applications on the southern edge. For loft conversion specifically, parts of Tresillian 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 Tresillian drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure; 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 Tresillian project as a TR2-area job first — not a generic Cornwall job with a postcode bolted on.

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 Tresillian.

  • 01

    Cornish slate roofs come in a huge range of pitches — anything below a 30° pitch struggles to give usable headroom without raising the ridge.

  • 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.

Our process

How a Tresillian loft conversion project runs.

  1. Step 1

    Feasibility

    Roof, headroom, stair landing and structural assessment.

  2. Step 2

    Design

    Layout options that respect the staircase, headroom and bathroom positioning.

  3. Step 3

    Approvals

    Planning or permitted development confirmation, plus building regs.

  4. Step 4

    Build

    Sequenced to keep the family living downstairs throughout most of the work.

  5. 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.

FAQs

Tresillian Loft Conversions — common questions.

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. In Tresillian specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
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.
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.
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.

Planning a loft conversion project in Tresillian?

Start a conversation