Knowledge · Cornwall
Cornwall planning, consent and construction guides
61 guides covering the questions we are asked most often across Cornwall — which consent applies, what a conversion really involves, which materials survive coastal exposure, and how long each stage actually takes.
Project types
- Garage conversions in Cornwall
Turning a Cornish garage into a habitable room: floor build-up, damp, insulation and building regulations drawings. Free first consultation across Cornwall.
- Barn conversions in Cornwall
Cornish barn conversions designed around Class Q limits, structural viability and heritage fabric. Feasibility, planning drawings and building regulations packages.
- Annexes and granny flats in Cornwall
Designing an annexe in Cornwall: ancillary use conditions, separate access, council tax and building regulations. Drawings and planning applications from a Cornish studio.
- Garden rooms and outbuildings in Cornwall
Garden offices, studios and outbuildings in Cornwall — permitted development limits, when regulations apply, and how to build something that lasts a Cornish winter.
- Which loft conversion suits your Cornish house? Velux, dormer, hip-to-gable or mansard
Velux, dormer, hip-to-gable and mansard loft conversions compared for Cornish houses — head height, roof pitch, planning risk and which suits your property.
- Knock-throughs and structural alterations
Removing walls, forming openings and opening up Cornish houses — structural calculations, building notices and drawings that let a builder price the work properly.
- Dormer loft conversions in Cornwall, choosing a dormer that suits the roof
Box, pitched and multiple dormers compared for Cornish roofs, with head height, planning limits, cheek detailing and weathering on exposed coastal elevations.
- Cob and stone repairs in Cornwall, working with walls that were never meant to be sealed
How Cornish cob and rubble stone walls actually behave, why cement and modern sealants damage them, and what a sympathetic repair specification should contain.
- Damp in old Cornish homes, diagnosing the cause before spending money on the symptom
Penetrating damp, condensation and rising damp behave differently. How to tell them apart in a Cornish cottage and what actually fixes each one for good.
- Slate roof replacement in Cornwall, the specification matters more than the slate
Replacing a slate roof on an exposed Cornish house: fixing patterns, underlay, ventilation, verges and the details that decide whether it survives thirty winters.
- Sloping sites in Cornwall, where the section matters more than the plan
Split levels, underbuild, retaining walls and access on steep Cornish plots, and how the section rather than the plan should drive the design.
Consents & planning
- Listed Building Consent in Cornwall
Listed Building Consent in Cornwall — what needs consent, heritage statements, appropriate materials and how to work with the conservation officer rather than against them.
- Conservation Areas in Cornwall
Designing in a Cornish Conservation Area — Article 4 directions, materials, rooflights and the detailing that gets an extension approved rather than refused.
- Permitted development in Cornwall
Permitted development for Cornish homes — extension limits, prior approval, and the designations across Cornwall that remove your rights without warning.
- Lawful Development Certificates
Certificates of lawfulness in Cornwall — proposed and existing use, what evidence is needed, and why solicitors ask for one at sale. Drawings and applications prepared locally.
- Pre-application advice in Cornwall
Cornwall Council pre-application advice — when it saves months, when it wastes money, and how to frame the questions so the response is actually useful.
- Refused planning permission in Cornwall
Refused planning permission in Cornwall? Understand the reasons, weigh appeal against resubmission, and use the free go on a revised application properly.
- Change of use in Cornwall
Change of use applications in Cornwall — holiday lets, annexes to dwellings, commercial to residential and principal residence policies in coastal towns.
- Do I need planning permission, or is it permitted development?
Planning permission or permitted development? A plain guide for Cornwall homeowners, what usually needs consent, what usually does not, and how to check properly.
- Planning application drawings, what a valid submission actually contains
The drawings a planning application actually needs in Cornwall, what scale they are drawn at, what gets applications held at validation and how to avoid it.
- Flood risk and surface water in Cornwall, the checks that decide whether a scheme is viable
How flood zones, surface water runoff and drainage strategy affect Cornish planning applications, and what to check before you design around a river or a valley floor.
- Off mains drainage in Cornwall, what rural sites have to prove before anything else works
Septic tanks, treatment plants and the general binding rules on Cornish rural sites, plus what a planning application and building control will expect to see.
- Second homes and principal residence policy in Cornwall, the condition that changes what a plot is worth
How principal residence conditions and local occupancy policies affect new homes in Cornish coastal parishes, and what to check before buying a plot or applying.
- Designing in the Cornwall National Landscape, what protected landscape status actually asks of a scheme
Designing inside the Cornwall National Landscape and Heritage Coast: what officers assess, how to handle massing, materials and light, and what usually gets refused.
- Mining legacy and ground conditions in Cornwall, the questions to ask before the foundation design
Shafts, adits, made ground and granite: how Cornwall's mining legacy affects foundations, searches and planning, and what to investigate before you design.
- Bat surveys and ecology in Cornwall, the constraint that is measured in seasons rather than weeks
When a Cornish planning application needs a bat or ecology survey, the seasonal survey windows, biodiversity net gain, and how to avoid losing a whole year.
- Access and highways in Cornwall, the consultee comment that quietly decides applications
Visibility splays, turning, parking standards and narrow lane access on Cornish applications, and how highways comments can decide a planning outcome.
Process & cost
- Building regulations, explained for people who are not builders
What building regulations approval actually involves in Cornwall — full plans versus building notice, the parts that matter, inspections and completion certificates.
- How long does a Cornwall project really take, from first call to starting on site?
A realistic Cornwall planning timeline — survey, design, validation, consultation, decision and discharge of conditions, with the stages that actually cause delay.
- What drives the cost of a Cornwall extension
What actually drives extension costs in Cornwall — ground conditions, access, glazing, exposure and finish level — and how to compare builder quotes fairly.
- Retrofitting an older Cornish house
Upgrading older Cornish homes — solid wall insulation, breathability, ventilation, heat pumps and the sequencing that avoids condensation and damp.
- Self-building in Cornwall
The self-build process in Cornwall — finding and appraising a plot, planning strategy, warranties, stage payments, VAT reclaim and procurement routes.
- Is that Cornish plot actually developable? The checks to run before you exchange
Independent plot appraisal in Cornwall — planning history, access, drainage, designations and policy constraints assessed before you commit to a purchase.
- What building regulation drawings actually include
A page by page look at what a building regulations package contains, from 1:50 plans to 1:10 junctions, and why the detail decides your builder's price and your approval.
- How much do architectural drawings cost, and what changes the price?
What drives the price of architectural drawings in Cornwall, which stages you pay for, and how to compare two quotes properly. Free first consultation.
- What is a measured survey, and when do you need one?
A measured survey is the accurate record every drawing depends on. What it captures, when it is needed, what changes the cost, and why old plans are rarely good enough.
- What happens after planning permission is approved?
Approval is the middle of the process, not the end. Conditions, building regulations, structural design, tendering and the checks to complete before work starts on site.
- Building an extension in Cornwall: the steps in order
Every stage of a Cornwall extension in the order it happens, from first consultation and survey through planning, building regulations, tender and completion certificate.
- Single storey extension costs in Cornwall, where the money actually goes
What a single storey extension really costs in Cornwall and what moves the number: ground, glazing, access and roof tie-in. Free first consultation, design and build.
- Two storey extension costs in Cornwall, and why the upper floor is the cheaper half
Two storey extension costs in Cornwall: why the first floor is not double, what foundations and roof tie-ins add, and how planning shapes the budget before design.
- Kitchen extension costs in Cornwall, two budgets that keep getting confused
Kitchen extension costs in Cornwall split into shell and fit out, with the drainage, structure and services decisions that quietly set the final figure.
- Loft conversion costs in Cornwall, four variables and everything else is detail
Loft conversion costs in Cornwall explained through head height, stair position, roof structure and dormer choice, plus the building regulation work involved.
- Construction drawings, the set the building actually gets built from
What construction and technical drawings contain, how they differ from planning drawings, and why they make builders' quotes comparable on Cornish projects.
- Structural calculations, what they cover and when building control will ask
When structural calculations are needed on Cornish projects, what they cover for beams, lofts and foundations, and how they are coordinated with the drawings.
- Build costs per square metre in Cornwall, and why the same rate gives two very different budgets
How build costs per square metre behave on Cornish sites, what pushes a rate up or down, and how to turn a rate into a budget you can actually plan around.
- Party wall agreements, when a Cornish project needs one and how to avoid losing two months to it
When the Party Wall etc. Act applies to a Cornish extension or loft, what notices are needed, how long they take and how to keep neighbours on side.
- Heat pumps in Cornish homes, why the fabric decides whether the system feels good
How air source heat pumps behave in Cornish housing, what fabric and emitter changes they need, and the planning and siting rules worth checking first.
- Solar and battery storage in Cornwall, designing it in rather than adding it afterwards
Roof orientation, structure, planning limits and battery siting for solar on Cornish homes, and how to design it in rather than retrofit it awkwardly later.
- Build over agreements, the drain under your garden that changes the foundation design
When an extension crosses a public sewer, what a build over or build near agreement involves, how long it takes and how it changes foundation design.
- Choosing a builder in Cornwall, how to compare three quotes that are actually comparable
How to compare Cornish builders fairly, what a tender pack should contain, which questions actually predict a good build, and how to structure payments.
- Budget and contingency planning, the lines homeowners forget until the money is gone
How to build a project budget that survives tender returns: the lines people forget, sensible contingency, cash flow and where costs actually escalate.
- VAT on building work, why two similar Cornish projects can carry very different tax
Why new build, conversions, long term empty homes and listed work are treated differently for VAT, and what to confirm before budgeting a Cornish project.
Comparisons
- Timber frame or blockwork for a Cornish build? Judge it on the site, not the ideology
Timber frame, SIPs or traditional blockwork for a Cornish build — programme, exposure, thermal performance, cost profile and what suits your site.
- Architect or architectural designer? What the difference actually means for your project
The difference between an architect and an architectural designer in Cornwall — title protection, what each can do, fees, and when you genuinely need a registered architect.
- Building on the Cornish coast
Designing for Cornish coastal exposure — wind-driven rain, salt corrosion, render, slate hanging, cladding and glazing choices that survive more than five winters.
- Planning permission versus building regulations, explained plainly
Two different systems, two different approvals. What planning permission covers, what building regulations cover, and how the two run alongside each other on a build.
- Windows in old Cornish buildings, balancing warmth, character and what consent will allow
Sash, casement and secondary glazing options for older Cornish homes, what Conservation Area and listed status allow, and how to balance heat, sound and character.
Audiences
- Landlord conversions and HMOs in Cornwall
Drawings and design for Cornish landlords — HMO layouts, flat conversions, fire strategy, room sizes and the documentation licensing officers expect.
- Shopfronts and small commercial work in Cornwall
Shopfront design, advertisement consent, hospitality fit-outs and small commercial alterations in Cornwall — including Conservation Area high streets.
- Farm diversification in Cornwall
Farm diversification in Cornwall — barn conversions, glamping and holiday accommodation, workshops and agricultural buildings, with the planning routes for each.
- Commercial drawings in Cornwall, what a fit out or change of use needs
Commercial drawing packages in Cornwall for shopfronts, fit outs, change of use and holiday lets, covering fire strategy, accessibility and landlord requirements.
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