North Cornwall · TR5 · Cornwall Council North
Eco new builds in St Agnes — sustainable spec that stacks up
An eco new-build in St Agnes 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 TR5 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. Working in St Agnes means starting from the TR5 context — St Agnes is a former mining village on the north coast with a strong artistic community, AONB and World Heritage designation, and dramatic coastal mining ruins (Wheal Coates) on its doorstep, with a building stock that leans toward Edwardian guesthouses and AONB-sensitive replacement dwellings.
St Agnes sits in North Cornwall — just off the A39; covering TR5 from Mount Hawke, Mithian, Porthtowan outward.
- Conservation Area
- Cornwall AONB
- Cornish Mining World Heritage Site
- Coastal exposure zone
- ✓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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Free St Agnes feasibility call
Tell us about your new build. We reply within 1 working day — no obligation.
Page purpose
Drawings only, or drawings through to handover in St Agnes?
Both routes are open on a TR5 project, and the honest answer depends on whether you already have a builder you trust. Plenty of St Agnes 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 TR5 scope, not as one opaque figure
Scope
Scope options for St Agnes clients
These stages can be bought separately. Most TR5 projects use three of them.
Measured survey
An accurate record of what is actually there, which is where most avoidable cost is removed.
Heritage and design statements
Written justification where designation makes the design case as important as the drawing.
Structural coordination
Calculations coordinated with the drawings so building control sees one consistent story.
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.
Local watch-list
Common St Agnes pitfalls we plan around.
Watch #1
Conservation Area controls on materials, window proportions and roof form through central St Agnes
Watch #2
AONB landscape-impact testing on anything read in long views across North Cornwall
Watch #3
World Heritage Site heritage assessment where changes are visible in the mining landscape
Watch #4
Exposure detailing on miners' terraces — fixings, render systems and joinery specified for salt-laden air
Who this is for
Straight facts about working with us here
- Applications for St Agnes are handled through Cornwall Council, with Bodmin the nearest planning office we deal with regularly.
- Designated-area work is routine here, so heritage and landscape statements are produced alongside the drawings rather than outsourced.
- Drawings, planning and building regulations are all produced in-house, so a new build enquiry does not get passed between firms.
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.
What we focus on
New Builds considerations specific to St Agnes.
01
Replacement dwellings have specific volumetric tests — getting the ratio between existing footprint and proposed floor area right is the difference between approval and refusal.
02
Self-build CIL exemption requires the right documentation in the right order; missing a step costs five-figure sums.
03
Cornwall's housing policy increasingly favours principal residence and replacement dwelling schemes over open-market new builds in some parishes.
04
AONB and Heritage Coast designations apply to large stretches of the county; isolated new builds outside settlement boundaries face a much higher policy bar.
Quick check
Want a straight answer on whether your St Agnes 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 St Agnes and the TR5 area.
Local context
Why St Agnes is its own job.
Two things shape a St Agnes application: parish character and policy. On policy — conservation Area covers Vicarage Road, Town Hill and the church area. AONB, Heritage Coast and World Heritage Site designations across the parish. Mining heritage shapes most planning conversations. For new build specifically, parts of St Agnes 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; 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 St Agnes drives detailing choices — fixings, render systems and timber treatments all need to be specified for exposure. Get that local reading right and the rest of the St Agnes programme tends to run on time. On Edwardian guesthouses in particular — the kind you'll also find toward Porthtowan — the new build brief always has to read the existing fabric first. 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.
Our process
How a St Agnes 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
St Agnes New Builds — local questions answered.
- Is timber-frame or block best for eco in St Agnes?
- 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 St Agnes?
- 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.
- 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. In St Agnes specifically, we'd start by checking the Conservation Area boundary before committing to a direction.
- What's a replacement dwelling and is mine eligible?
- If a habitable dwelling exists on the plot, you can often replace it — within volumetric and design constraints set by Cornwall's Local Plan. Derelict structures sometimes qualify, sometimes don't, depending on lawful use history.
- 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.
St Agnes is the hub for these neighbourhoods
We run new builds across St Agnes and the surrounding TR5 neighbourhoods — same studio, same site team.
- Goonbell
TR5
Keep reading
Where to go next from St Agnes
St Agnes works as a hub for us: the same new build team covers Goonbell and the surrounding TR5 villages, so a site visit here often takes in more than one address.
Other services in St Agnes
Not every St Agnes 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.
Design an eco new-build on your St Agnes plot
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