Planning Permission in Isles of Scilly
Unitary Authority in South West · Last updated April 2026
The Isles of Scilly is England's smallest planning authority, an archipelago of around 140 islands and islets lying 28 miles off the Cornish coast. With just one conservation area, 129 listed buildings, and the entire island group designated as an Area of Outstanding Natural Beauty and Heritage Coast, planning here is uniquely sensitive.
The council processes around 65 applications per year with a 92.4% approval rate. Given the islands' fragile environment, limited building materials supply, and tight-knit communities, the planning process is personal and collaborative, with most applications discussed directly with the planning team.
All development on the Isles of Scilly should be considered within the context of the Local Plan and the islands' AONB status. The unique logistics of island construction — including material transport by sea — also influence what is practical and achievable.
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What can I build in Isles of Scilly?
| Project type | Likely permitted development | May need planning permission | Likely needs planning permission |
|---|---|---|---|
| Rear extension (single storey) | Most of Isles of Scilly outside protected zones | Properties near boundaries | Conservation areas (1), listed buildings |
| Rear extension (two storey) | Most of Isles of Scilly outside protected zones, if within 3m limit | Check distance to boundary ≥7m | Conservation areas (1), listed buildings |
| Side extension | Detached houses outside protected zones | Semi-detached properties (half-width rule) | Conservation areas (1), listed buildings |
| Loft conversion (dormer) | Houses outside conservation areas | Properties on prominent corners | Conservation areas, listed buildings, flats |
| Loft conversion (Velux/rooflight) | Most of Isles of Scilly | Front-facing rooflights in conservation areas | Listed buildings |
| Outbuilding / garden office | Most of Isles of Scilly outside protected zones, if within size/height limits | Large outbuildings covering >50% of garden | Conservation areas (side or front), listed buildings |
| Porch | Most properties if within 3m² and 3m height | Properties near highway boundary | Conservation areas with restrictions, listed buildings |
| Solar panels | Most properties (roof-mounted) | Panels protruding beyond roofline | Listed buildings, conservation areas (if visible from road) |
| Driveway / hard standing | If using permeable surfacing | Non-permeable surfacing over 5m² | Conservation areas with specific restrictions |
| Garage conversion | Most of Isles of Scilly (internal works) | If changing external appearance significantly | Listed buildings |
This is general guidance based on Isles of Scilly's planning constraints. Your specific property may differ — use our free PD checker to get a result tailored to your address.
Permitted development in Isles of Scilly
Despite the islands' extensive environmental designations, standard permitted development rights apply to most householder properties on the Isles of Scilly. The single conservation area and 129 listed buildings are the main constraints on PD rights. However, the AONB designation covering the entire archipelago means that any planning application will be assessed for its landscape impact. The small scale of the islands means that even modest developments can have a significant visual and environmental effect.
What Isles of Scilly expects from your project
Local Plan: Isles of Scilly Local Plan
The Council of the Isles of Scilly adopted its Local Plan in June 2005. The five inhabited islands some 28 miles south-west of Land's End form England's smallest unitary authority by population. Development is very strictly controlled to protect the internationally important habitats, tourism economy and the unique character of the island communities.
Emerging / replacement plan
The Council of the Isles of Scilly is preparing a new Island Plan. Given the islands' unique circumstances, the plan preparation process is bespoke. A new plan has been in preparation since 2016 and consultation on a Regulation 19 document is anticipated in 2025.
92.4% approval rate
Isles of Scilly approves 92.4% of planning applications, above the national average of 86.9%. Well-designed residential applications in this area tend to have a good chance of success.
Conservation areas in Isles of Scilly
1 designated conservation area
The Isles of Scilly has one conservation area covering the main settlement on St Mary's. Properties within this area face the standard conservation area restrictions on extensions, dormers, and external alterations. Beyond the conservation area, the islands' 129 listed buildings — a high density given the small population — require listed building consent for any alterations. The distinctive granite architecture of the islands is a key element of their character.
Article 4 directions in Isles of Scilly
Article 4 direction data for Isles of Scilly has not yet been published to the national planning data platform. This does not mean there are no Article 4 directions in this area. Contact Isles of Scilly's planning department directly or use our free PD checker to check whether your property is affected.
Listed buildings in Isles of Scilly
There are 129 listed buildings in Isles of Scilly. If your property is listed, permitted development rights are significantly restricted. Most external and many internal alterations will require listed building consent, which is separate from planning permission. Always check with Isles of Scilly's conservation team before starting any work on a listed property.
Planning application statistics
Year ending September 2025 | Source: MHCLG planning application statistics
Isles of Scilly received 65 planning applications and decided 66 in the year ending September 2025. The approval rate of 92.4% is above the national average of 86.9%. Major applications are expected to be decided within 13 weeks, while householder and other non-major applications have an 8-week target. The “in time” figures include decisions made within agreed extensions of time.
The Council of the Isles of Scilly handled 65 planning applications in the year ending September 2025, making it England's smallest planning authority by volume. The approval rate was 92.4% across 66 decisions. The council processed 20 householder applications with a 90% on-time rate. The delegation rate of 77.3% is lower than the national average, reflecting the close involvement of elected members in planning decisions on the islands.
If your project complies with permitted development rules, you don't need to worry about approval rates — a Lawful Development Certificate is a factual assessment, not a judgment call.
Recent planning applications in Isles of Scilly
Browse what's been approved near you
Seeing what similar projects have been approved near your property can help you understand what Isles of Scilly expects in terms of scale, materials, and design. It's also useful for gauging how quickly the council processes applications.
Search planning applications on Isles of Scilly's portal →Data from MHCLG planning application register. Search for householder applications (H01/H02) to see extensions and loft conversions in your area.
Lawful Development Certificates in Isles of Scilly
A Lawful Development Certificate (LDC) is formal confirmation from Isles of Scilly that your project is lawful under permitted development rules. It is not legally required before you build, but it is the only official document that proves your project did not need planning permission. Most solicitors will ask for one when you come to sell, remortgage, or insure your property.
Isles of Scilly decided 20 householder applications in the year ending september 2025. Their 8-week performance of 90% is below the national average of 93%, so LDC applications may take longer than the 8-week target. LDC applications follow the same 8-week statutory determination period as householder planning applications.
How to apply for an LDC in Isles of Scilly
You can apply for a Lawful Development Certificate through the Planning Portal or directly through Isles of Scilly's website. You will need to submit:
- A completed application form (available on the Planning Portal)
- A site location plan at 1:1250 or 1:2500 scale
- Existing and proposed floor plans and elevations
- A written description of the proposed works and how they comply with the GPDO 2015
- The application fee of £258
Isles of Scilly must issue a decision within 8 weeks. If the application is approved, the certificate is a permanent legal record that the development is lawful. If refused, you can appeal to the Planning Inspectorate or amend your project and reapply.
Need help preparing your LDC application?
Our Permitted Development Certificate Report gives you a full PD eligibility assessment, property constraints check, and application checklist tailored to your address and project — so you can apply with confidence.
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Approval rates, decision patterns, Article 4 directions, fees & timelines, and council-specific tips for Isles of Scilly.
Pre-application advice in Isles of Scilly
Isles of Scilly offers a pre-application advice service.
Pre-app advice is worth paying for if your project is borderline, your property is in a conservation area, or your home is a listed building.
Think your project might be permitted development?
Check in 2 minutes with our free tool — no sign-up needed.
Check your PD rights now →The Council of the Isles of Scilly offers pre-application advice. Contact the planning team directly for guidance on proposed development.
Planning fees and timelines in Isles of Scilly
| Application type | Fee | Typical timeline |
|---|---|---|
| Householder planning application | £528 | 8 weeks |
| Full planning permission | £610 per dwelling | 8-13 weeks |
| Lawful Development Certificate (proposed) | £264 | 6-8 weeks |
| Lawful Development Certificate (existing) | £298 | 6-8 weeks |
| Listed building consent | Free | 8 weeks |
| Prior approval | £120 | 56 days |
| Discharge of conditions | £145 per request | 8 weeks |
| Non-material amendment | £44 | 28 days |
Fees are set nationally and correct as of April 2026. Pre-application fees are set by Isles of Scilly and may change. Building regulations fees are separate — see the building control section below.
Building regulations in Isles of Scilly
Building regulations approval is separate from planning permission. Most extensions, loft conversions, and structural alterations need building regs approval even if they don't need planning permission.
Building control in Isles of Scilly is provided by Isles of Scilly Building Control. You can also use a private approved inspector instead of the council's service.
Building control contact
Council of the Isles of Scilly Building Control.
Isles of Scilly planning department
Your building project checklist for Isles of Scilly
- Check if your property is in a conservation area — Isles of Scilly has 1 conservation areas. Use our free checker or see the list above.
- Check for Article 4 directions at your address — Check your address for any restrictions.
- Check if your property is listed — search the Historic England list.
- Use our free PD checker to see if your project qualifies as permitted development — Check now.
- Consider a Lawful Development Certificate if PD applies — it protects you when selling. Learn more about LDCs or get your PD Certificate Report.
- Consider pre-application advice if planning permission is needed — see the pre-application section above.
- Check building regulations — most extensions and loft conversions need building regs approval even if they don't need planning permission.
- Check Party Wall Act obligations if building near a boundary — read our Party Wall guide or use our free Party Wall tool.
- Notify your home insurer about planned building work.
- Get at least 3 quotes from builders and check their credentials.
Nearby planning authorities
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