Lizard Peninsula · TR12 · Cornwall Council West
Eco new builds in Mullion — sustainable spec that stacks up
An eco new-build in Mullion doesn't have to be Passivhaus-certified to make sense. Timber-frame construction, wood-fibre insulation, triple glazing and a properly sized air-source heat pump get you 85–90% of Passivhaus performance for a build premium under 6%. On TR12 plots, this is the pragmatic middle ground. 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 — just off the A394; covering TR12 from Mawgan, Ruan Minor, The Lizard outward.
- Conservation Area
- Cornwall AONB
- Coastal exposure zone
- Rural / open-countryside policy area
- ✓Timber-frame with wood-fibre insulation
- ✓ASHP + underfloor + PV as standard
- ✓Under 6% cost premium
- ✓Full building regs sign-off included
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Local watch-list
The TR12 constraints that shape a new build brief.
Watch #1
Conservation Area controls on materials, window proportions and roof form through central Mullion
Watch #2
AONB landscape-impact testing on anything read in long views across Lizard Peninsula
Watch #3
Exposure detailing on granite cottages around the church — fixings, render systems and joinery specified for salt-laden air
Watch #4
Local Plan tests on isolated dwellings, plus lane access for plant and deliveries around Mullion
Who this is for
In Mullion the new build brief is almost always a private homeowner improving a forever home — so we lead with feasibility and long-term value, not show-home rhetoric.
Scope
The parts of the job we can take on in Mullion
Clients in Mullion take different slices of this list, and that is deliberate.
Full design and build
One contract from first sketch to handover, with the same team on paper and on site.
Construction and technical drawings
1:10 and 1:20 details for the parts of the job builders normally have to guess at.
Building regulation drawings
Full Plans sets with sections, construction notes and coordinated structural information.
Planning application drawings
Existing and proposed plans, elevations, site and block plans drawn to validation standard.
Measured survey
An accurate record of what is actually there, which is where most avoidable cost is removed.
Who this is for
What we can genuinely back up in Mullion
- Design and build are offered from the same studio, which means the person answering your Mullion questions has seen the detail built.
- Drawings, planning and building regulations are all produced in-house, so a new build enquiry does not get passed between firms.
- Designated-area work is routine here, so heritage and landscape statements are produced alongside the drawings rather than outsourced.
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
Other work we do around Mullion
We cover Mullion and the wider TR12 district directly. New Builds enquiries here are common enough that we know the constraints before the first visit.
Page purpose
Drawings only, or drawings through to handover in Mullion?
Both routes are open on a TR12 project, and the honest answer depends on whether you already have a builder you trust. Plenty of Mullion 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 TR12 scope, not as one opaque figure
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. Historic fabric changes the sequence: survey first, then design around what the building can take. Consent routes for listed buildings sit separately from ordinary planning, so treat any general guidance here as a starting point and check with Cornwall Council. Coastal sites tend to raise questions about roof form, glazing exposure and how a scheme reads from public viewpoints. Those are policy judgements rather than fixed rules, so the local planning authority or the Planning Portal should confirm the position for a given plot.
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.
What 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.
Quick check
Want a straight answer on whether your Mullion 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 Mullion and the TR12 area.
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.
FAQs
Mullion New Builds — local questions answered.
- Is timber-frame or block best for eco in Mullion?
- Timber-frame nearly every time — lower embodied carbon, faster on-site programme, better air-tightness detailing. The exception is exposed coastal plots where masonry may still win on maintenance.
- What eco heating works in Mullion?
- Air-source heat pump with underfloor heating downstairs, radiators upstairs. Ground-source only makes sense on plots with borehole space. PV on the roof pays back in 9–12 years at current rates.
- Does eco spec add much cost?
- £3,200–£4,200/m² for sensible eco spec vs £3,000–£4,000 standard. Under 6% premium for major improvements in comfort and running cost.
- 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.
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.
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Nearby places we cover
Not every Mullion eco home needs full Passivhaus certification — sensibly specified timber-frame with the right envelope gets most of the benefit for a fraction of the premium.
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