Lizard Peninsula · TR12
Passivhaus architect in Mullion — low-energy homes done properly
Passivhaus in Mullion is not a marketing sticker — it's a numbers-driven design method that requires orientation modelling, air-tightness planning and MVHR sizing from the first sketch. On coastal plots in TR12, the wind exposure is the first variable we test in PHPP. A bespoke new build is the longest project we do, and the most rewarding. From plot appraisal through planning, building regulations and construction, you work with one team from the first sketch to the handover walk-round. Reading Mullion on the ground is half of the new build job — 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 Edwardian guesthouses 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
- ✓ Full PHPP modelling available
- ✓ MVHR sizing and air-tightness planning
- ✓ 8–15% build premium, ~zero running cost
- ✓ Cost: £3,600–£4,800/m² built
Our process
How a Mullion new build project runs.
Step 1
Plot review
Site visit, planning history check, designation review and an honest feasibility verdict.
Step 2
Concept design
Sketches that test the plot in massing, orientation and approach before any drawings are committed.
Step 3
Planning
Pre-app, full planning, consultee management and condition discharge.
Step 4
Technical design and build prep
Building regs, structural design, services strategy and contractor procurement.
Step 5
Construction and handover
Build delivered under contract administration with regular client reviews.
Most bespoke new builds run eighteen to thirty months from instruction to keys, depending on site, planning route and build complexity.
Local proof — Our Lizard Peninsula workload means a Mullion new build project never has to wait for an out-of-county team to drive down.
Get a free feasibility viewWhat we focus on
New Builds considerations specific to Mullion.
01
Self-build CIL exemption requires the right documentation in the right order; missing a step costs five-figure sums.
02
Cornwall's housing policy increasingly favours principal residence and replacement dwelling schemes over open-market new builds in some parishes.
03
Off-grid services — package treatment plants, borehole supply, off-mains gas — are common on rural Cornish plots and need designing, not assuming.
04
Replacement dwellings have specific volumetric tests — getting the ratio between existing footprint and proposed floor area right is the difference between approval and refusal.
Local context
Why Mullion is its own job.
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 new build 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. So every Mullion job runs as a TR12-specific piece of work — local policy, local fabric, local builders. Most of our new build work in Mullion lands on Edwardian guesthouses, with detailing that has to nod to the wider The Lizard streetscape.
Planning note
Cornwall's planning policy on new dwellings is among the most restrictive in England outside Greater London. The first conversation should be a planning conversation, not a design one.
Local watch-list
The TR12 constraints that shape a new build brief.
Watch #1
Conservation Area material and fenestration controls in central Mullion
Watch #2
AONB landscape-impact scrutiny on visible elevations
Watch #3
Coastal exposure driving fixing, render and joinery spec
Watch #4
Tighter Local Plan tests on isolated rural dwellings
Mullion is the hub for these neighbourhoods
We run new builds across Mullion and the surrounding TR12 neighbourhoods — same studio, same site team.
- Cury
TR12
- Gunwalloe
TR12
- Predannack
TR12
Local fabric
Mullion new builds — the local-studio difference.
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 new build response — Edwardian guesthouses 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 new build jobs also running in Mawgan, Ruan Minor, The Lizard. Most Mullion site visits get booked within the same week.
Do you work in Mullion regularly?
Yes — Mullion and the wider TR12 catchment are core territory. We're typically on a Lizard Peninsula site at least once a week, so logistics are baked in, not bolted on.
Request a free visitWho this is for
Mullion runs the full mix — owner-occupier, holiday-let, commercial and the occasional smallholding — so we scope every new build enquiry from the use-class up.
FAQs
Mullion New Builds — local questions answered.
- Is Passivhaus worth it in Mullion?
- Financially, the 8–15% build premium pays back in 15–20 years at current energy prices. Comfort-wise, the payback is immediate. On new-builds in TR12, we recommend it on any plot with reasonable orientation.
- Do you produce full PHPP models?
- Yes, or we work alongside a certified PHPP consultant. Either route lands the same result — a fully modelled, air-tightness-tested certified Passivhaus.
- What's the cost difference vs a standard new build?
- £3,600–£4,800/m² for Passivhaus vs £3,000–£4,000/m² for a well-insulated standard build. Premium is smaller than most people expect.
- How long does the whole project take?
- Allow six to twelve months for design and approvals, then ten to fourteen months on site for a typical four-bedroom new build. Complex sites or long planning routes extend that. In Mullion specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- What about utilities, drainage and access?
- All designed and applied for as part of the package — water, electric, off-mains drainage where mains isn't viable, and highways access agreement with Cornwall Council where required.
- Can I build a new house on my plot in Cornwall?
- Sometimes yes, sometimes no — and the honest answer needs a planning policy review of the specific site. Settlement boundary, designations, access and policy on isolated dwellings all weigh in. We give a frank read at first consultation rather than a sales pitch.
Other services in Mullion
Nearby places we cover
Local neighbourhoods in Mullion
A Mullion Passivhaus costs 8–15% more to build and roughly nothing to run — the payback is in comfort as much as bills, and the resale market for certified homes is strengthening year on year.
Book a Passivhaus feasibility for your Mullion plot
Free · No obligation
Book a free visit in Mullion
No obligation. Reply usually same working day.