Lizard Peninsula · TR12
Hip-to-gable loft conversions in Mullion — the extra metres explained
Hip-to-gable is the most misunderstood loft type in Mullion. On a semi-detached with a hipped roof, extending the hip out to a vertical gable adds around 8–12m³ of usable volume — often the difference between a poky guest room and a proper master with en-suite. Combined with a rear dormer, it's the highest-yield loft move you can make in TR12. 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. On a Mullion site, the brief always meets the place — Mullion is the largest village on the Lizard Peninsula, AONB-designated, with a fifteenth-century church, a working cove and the highest concentration of period housing on the peninsula, with a building stock that leans toward granite cottages around the church and modern AONB-sensitive replacement dwellings.
Mullion sits in Lizard Peninsula — covering TR12 from Mawgan, Ruan Minor, The Lizard outward.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
- Rural / open-countryside policy area
- ✓ Adds 8–12m³ of usable volume
- ✓ Best combined with a rear dormer
- ✓ Cost: £65k–£95k built
- ✓ PD on semi/detached outside Conservation Areas
Local proof — Our Lizard Peninsula workload means a Mullion loft conversion project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewLocal context
Why Mullion is its own job.
Locally, mullion Conservation Area covers the village centre; the wider parish is entirely within the AONB and includes Heritage Coast designation. Cliff-edge and coastal margin sites face the strictest controls in West Cornwall. For loft conversion specifically, parts of Mullion 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 Mullion 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. Which is why we scope Mullion projects parish-up, not template-down — the TR12 context shapes the design from day one. Whether the project is on granite cottages around the church in the centre or further out toward Cury, 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 Mullion.
01
Cut-roof Cornish properties are easier to convert than modern trussed roofs; the structural strategy varies completely.
02
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.
03
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.
04
Stairs eat space — a loft conversion lives or dies by where the new staircase lands and what it costs you on the floor below.
Our process
How a Mullion 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
Choosing a loft conversion team that actually knows TR12.
Building stock
Across Mullion (TR12) we work on granite cottages around the church, Edwardian guesthouses, 1960s coastal bungalows, modern AONB-sensitive replacement dwellings. Each stock type drives a different loft conversion response — granite cottages around the church in particular needs careful detailing here.
Parish & policy
Mullion is its own town in Lizard Peninsula, with planning history that's specific to the TR12 catchment.
Coverage
We cover TR12 from our studio, with regular loft conversion jobs also running in Mawgan, Ruan Minor, The Lizard. Most Mullion site visits get booked within the same week.
What does a first Mullion consultation cost?
Nothing. We come to the property, walk the site, talk through what works on a TR12 plot and follow up with a written feasibility note inside a week — no obligation either way.
Request a free visitFAQs
Mullion Loft Conversions — local questions answered.
- What's a hip-to-gable loft conversion?
- The sloping "hip" end of the roof is rebuilt as a vertical gable wall, adding roughly 8–12m³ of habitable volume. Almost always combined with a rear dormer.
- Do I need planning for a hip-to-gable in Mullion?
- Yes — Conservation Area removes hip-to-gable from PD entirely.
- How much does a hip-to-gable + dormer cost in Mullion?
- £65k–£95k for the combined works, including new stair, master bedroom and en-suite. Timber cladding on the new gable is popular and adds ~£4k.
- 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. In Mullion specifically, we'd start by checking the Conservation Area boundary 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.
- 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.
Mullion is the hub for these neighbourhoods
We run loft conversions across Mullion and the surrounding TR12 neighbourhoods — same studio, same site team.
- Cury
TR12
- Gunwalloe
TR12
- Predannack
TR12
Other services in Mullion
Nearby places we cover
Local neighbourhoods in Mullion
A Mullion hip-to-gable only makes sense on properties with a hipped side roof — but where it applies, no other loft type gives more usable space for the money.
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