A large part of Cornwall is protected for its landscape or its history. Around a quarter of the county sits within the Cornwall National Landscape, which was known until recently as the Cornwall Area of Outstanding Natural Beauty (AONB), and many towns and villages have conservation areas. If your home is in one of these areas, you can still extend, renovate or build, but the rules are tighter and design matters more. This guide explains what changes and how to plan a project that has the best chance of going smoothly.
How do I know if my property is in a protected area?
Cornwall Council's online mapping shows planning constraints for each address, including the National Landscape boundary, conservation areas and listed buildings. Your property's deeds or previous planning decisions may also mention them. Coastal areas such as the Camel Estuary around Padstow and Rock, much of the north and south coast, and areas like Bodmin Moor fall within the National Landscape, while many historic town centres and harbour villages are conservation areas.
It's worth checking before you design anything, because the designation can change what you're allowed to do without an application.
What changes in the Cornwall National Landscape (AONB)?
Homes in a National Landscape still have permitted development rights, but some are reduced. As general guidance, in these areas:
Side extensions usually need planning permission.
Cladding the outside of a house (for example in timber, stone or render) usually needs permission.
Some of the larger rear extension allowances available elsewhere don't apply.
Outbuildings to the side of a house, and larger outbuildings set further away from it, can be more restricted.
Where an application is needed, Cornwall Council will look at how the proposal affects the landscape and views, as well as the usual matters like neighbours and design. The Cornwall National Landscape Management Plan sets out the kind of design, materials and scale that fit the area, and it's a useful reference for your architect.
Permitted development rules are detailed and do change, so always confirm with Cornwall Council or a planning professional before starting work.
What changes in a conservation area?
Conservation areas protect the character of a place rather than the wider landscape. As well as reduced permitted development rights similar to those above, you may need permission for:
Demolishing a building or a significant part of one
Some works to boundary walls, gates and fences
Changes to the roof, such as dormers on certain elevations
Work to trees, which usually needs six weeks' notice to the council
Some conservation areas also have Article 4 Directions, which remove further rights, such as replacing original windows or doors. Your council can tell you if one applies.
If the property is listed, listed building consent is needed for any works affecting its character, inside or out, and this is separate from planning permission.
Design tips for protected areas
Projects that respect their setting tend to have a smoother path. Things that usually help:
Materials that fit the area. Natural slate, local stone, lime render and timber often sit better than bright or reflective finishes. Our stone, rendering and lime work team works with traditional materials.
Scale and massing. Keep extensions subordinate to the main house, with rooflines that sit below the original ridge.
Views and skylines. On exposed sites, think about how the building looks from the coast path, the estuary or the road.
Glazing and lighting. Large areas of glass can cause light spill at night, which matters in dark landscapes.
Landscaping. Retaining Cornish hedges, trees and natural boundaries helps a project blend in.
Other checks that often come up
Protected areas often go hand in hand with other surveys. Older buildings and barns may need a bat survey, and coastal or rural sites may need ecology or drainage information. Building near the coast can also raise questions about erosion or flood risk. Allowing time for these at the start avoids delays later.
How we can help
We regularly build in sensitive locations across North Cornwall, from home extensions and barn conversions to new builds. We can work alongside your architect and planning consultant to make sure the build matches the approved drawings and conditions, and our property renovation work often involves traditional materials and details. For a wider overview of applications, read our planning permission guide.
AONB and conservation area FAQs
Is it harder to get planning permission in an AONB?
Not necessarily harder, but proposals are judged more closely on their impact on the landscape. Good, sympathetic design and early advice make a real difference.
Is the Cornwall AONB the same as the Cornwall National Landscape?
Yes. Areas of Outstanding Natural Beauty in England were renamed National Landscapes in 2023. The legal protection is the same.
Can I build a garden room in an AONB?
Often, yes, but the permitted development limits for outbuildings are tighter in these areas, so check before you order anything. See our garden offices page for more.
Do I need permission to replace windows in a conservation area?
For a house, often not, unless an Article 4 Direction applies or the building is listed. Flats and commercial properties have different rules.
Planning a project in a protected area?
If your home is in the Cornwall National Landscape or a conservation area and you're thinking about building work, call Cornish Building Company on 01208 816991 or contact us here to talk it through.
