Planning Permission in Cornwall: Homeowner’s Guide

23 Oct

If you're thinking about extending, converting or building a new home in Cornwall, planning permission is usually the first hurdle. The rules are set nationally, but they are applied locally by Cornwall Council, and Cornwall has more protected landscape, coastline and historic buildings than most parts of the country. This guide explains how the process works, when you might not need permission at all, and how to give your application the best chance of success.

Who decides planning applications in Cornwall?

Cornwall Council is the local planning authority for the whole county (the Isles of Scilly have their own council). Applications are submitted online, usually through the Planning Portal, and are then checked, publicised and assessed by a council planning officer. Most straightforward householder applications are decided by officers; larger or more controversial schemes can go to a planning committee.

Decisions are made against national policy and the Cornwall Local Plan, plus any neighbourhood plan adopted by your town or parish. Many Cornish parishes now have neighbourhood plans, and some include policies that go further than the Local Plan. St Ives, for example, has a principal residence policy that restricts new-build open-market homes to people living there as their main home. It's always worth checking whether your parish has one before you design anything.

Do you actually need planning permission?

Not always. Many smaller projects fall under permitted development rights, which allow certain work on houses without a full application. In general terms, these can include:

Single-storey rear extensions within set size limits (typically up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, with a larger allowance available through the prior approval process).
Some loft conversions, within volume limits and provided they don't face the road at the front.
Outbuildings such as garden rooms, home gyms and garden offices, if they meet the height, position and coverage rules and are used for purposes incidental to the house rather than as separate living accommodation.

There are important exceptions. Flats and maisonettes don't have the same rights, some homes have had their rights removed by a planning condition or Article 4 direction, and listed buildings need listed building consent for most changes, inside and out.

If you're relying on permitted development, it's sensible to apply for a Lawful Development Certificate from Cornwall Council. It isn't compulsory, but it gives you written confirmation that the work is lawful, which helps when you come to sell.

Building in a National Landscape or conservation area

Around a quarter of Cornwall sits within the Cornwall National Landscape (formerly the Cornwall Area of Outstanding Natural Beauty), including large stretches of the north coast around Padstow, Rock and Polzeath. Many town and village centres are also conservation areas.

In these areas, permitted development rights are reduced. For example, side extensions, two-storey rear extensions and cladding the outside of a house usually need a full application, and outbuildings to the side of the house are more restricted. Planners will also look closely at design, materials and how a building sits in the landscape. Local slate, natural stone, lime render and timber cladding are often favoured, and large expanses of glass facing open countryside or the coast may draw comment.

None of this means you can't build. It means the design needs to respond carefully to its setting, and it's worth getting that right before you submit.

The application process, step by step

Pre-application advice. Cornwall Council offers a paid pre-application advice service. For anything beyond a simple extension, this can flag problems early and save a refused application.
Drawings and supporting documents. You'll need a location plan, site plan, existing and proposed drawings, and an application form. Depending on the site, you may also need a design and access statement, a heritage statement, an ecology survey (bats and nesting birds are common considerations in older Cornish buildings), a flood risk assessment or a drainage strategy.
Submission and validation. The council checks that everything required is there and that the fee has been paid. Current fees are published on the Planning Portal.
Consultation. Neighbours are notified, a site notice may be put up, and the town or parish council is consulted. There's normally a 21-day period for comments.
Decision. The target for householder and minor applications is 8 weeks from validation, and 13 weeks for major schemes. Complex cases can take longer, particularly if amendments are needed.
Conditions. Most approvals come with conditions, such as agreeing materials before work starts. Some must be discharged before you begin on site, so read them carefully.

If permission is refused, you can amend the scheme and reapply, or appeal to the Planning Inspectorate.

Planning permission and building regulations are different

This catches a lot of people out. Planning permission is about whether a development is acceptable in principle and in appearance. Building regulations cover how it's built: structure, fire safety, insulation, ventilation, drainage and so on. Most extensions, loft conversions, barn conversions and new builds need building regulations approval whether or not they need planning permission. This can come from Cornwall Council's building control team or an approved private inspector.

Common projects and what to expect

Home extensions: many single-storey rear extensions can be done under permitted development; larger, two-storey or side extensions usually need an application.
Loft conversions: rear dormers are often permitted development; front dormers, raised roofs and work in protected areas generally aren't.
Barn conversions: some agricultural buildings can be converted under the Class Q prior approval route, but it has strict criteria and doesn't apply in National Landscapes or conservation areas. Otherwise, a full application is needed.
New builds and self-builds: always need full planning permission, and site constraints such as access, drainage and ecology are assessed in detail.
Garden offices, home gyms and saunas: often permitted development if they're sized and positioned correctly, but not if they're used as a separate dwelling.

Tips for a smoother application

Check your property's planning history and any restrictions on Cornwall Council's online planning register.
Talk to your neighbours early; objections are often about things that could have been resolved with a conversation.
Use materials and a scale that suit the area, especially near the coast.
Allow time for surveys. Bat surveys, for example, can only be carried out at certain times of year.
Work with a builder who can comment on buildability and cost while the design is still on paper.

Frequently asked questions

How long does planning permission take in Cornwall? The target is 8 weeks for householder and minor applications once validated, and 13 weeks for major developments. Allow extra time for preparing drawings and surveys beforehand.

How long does planning permission last? Normally 3 years from the decision date. You need to have lawfully started the work within that time.

Can I start work before I get planning permission? You can, but it's a risk. If permission is refused, the council can take enforcement action and require the work to be removed.

Do I need planning permission to replace windows in a conservation area? It depends on the property and whether an Article 4 direction applies. Listed buildings will need consent. Check with Cornwall Council before ordering.

Talk to Cornish Building Company

We build extensions, conversions, renovations and new homes across Cornwall, from Padstow and Rock to Wadebridge and beyond (see the areas we cover). We can work alongside your architect or designer and offer project management from planning through to completion.

To discuss your project, call us on 01208 816991 or get in touch through our contact page.