Planning permission is most often refused because a scheme conflicts with local or national policy, harms neighbours’ light or privacy, sits badly in the street, or lacks key drawings. Most of these refusals can be anticipated. Below are the ten most common reasons and what each means for a London house extension. If you have already been refused, you can amend and resubmit, or appeal. Careful work during the design phase lowers the risk before you submit.
Why do councils refuse planning permission?
A council refuses planning permission when it decides a proposal conflicts with its development plan and nothing else outweighs that conflict. In London, the development plan is the borough’s Local Plan plus the London Plan. Officers read it alongside the National Planning Policy Framework (NPPF) and the borough’s own extension design guidance.
Most householder applications are decided by a planning officer rather than a committee. The officer weighs the scheme against policy and against “material considerations”: overlooking, loss of light, design, parking, heritage and previous decisions on similar sites. If the answer is no, the council must give its reasons in writing on the decision notice.
The reasons below are the ones that come up again and again on extensions and loft conversions. Several often appear together on the same decision notice.
The 10 most common reasons planning permission is refused
1. The scheme conflicts with local planning policy
Every reason on a decision notice cites a policy, so a clash with the borough’s own rules is where most refusals start. Each London borough sets its own rules on the depth, height and roof form of rear extensions, side return infills, dormers and mansards. A scheme that ignores those rules is refused even if it looks good.
Read the borough’s residential design guidance before any drawings are fixed. Check whether the street has an Article 4 direction, which removes some permitted development rights and brings more work under full planning control.
2. Loss of daylight and sunlight to neighbours
Loss of light is one of the most common neighbour-related reasons for refusing an extension. On a terrace, a deep rear extension or a tall wall on the boundary can put the neighbour’s kitchen or living room window into shadow.
Many councils use a 45-degree test drawn from the neighbour’s nearest habitable-room window as a first check. Larger or borderline schemes may need a daylight and sunlight assessment based on the Building Research Establishment (BRE) guidance. Lowering the boundary wall height, stepping the extension in or using a sloping roof on the neighbour’s side often resolves the issue.
3. Overlooking and loss of privacy
Overlooking is refused where new windows, balconies or roof terraces look straight into a neighbour’s rooms or the private area of their garden closest to the house. Rear dormers with Juliet balconies and flat-roof terraces over extensions are frequent problems.
Obscure glazing, high-level windows, rooflights instead of side windows and the removal of terrace access usually overcome this objection without losing much space.
4. Overbearing scale and sense of enclosure
A council can refuse an extension that feels overbearing to neighbours, even if light loss is acceptable. A long, high wall running along a shared boundary can make the next-door garden feel enclosed. Wraparound extensions that build on both the side return and the rear are assessed especially closely for this reason.
5. Poor design or harm to the host building
Officers expect an extension to look subordinate to the original house. Refusals often cite bulk, a roof form that fights the original, materials that clash with the brickwork, or a dormer that fills the whole roof slope. A loft conversion that reads as an extra storey on a Victorian terrace is a typical example.
Good design is not about copying the original. A contemporary extension in matching or contrasting materials can be approved if its scale and proportions respect the house.
6. Harm to the character of the street
Anything visible from the road gets more scrutiny than work at the back. Side extensions on corner plots, front dormers and roof extensions that break a consistent roofline along a terrace are common reasons for refusal on character grounds.
Look at what the street already has. If neighbours have similar dormers or extensions with permission, their approvals can support your case. Unauthorised examples carry far less weight.
7. Conservation areas and listed buildings
In a conservation area, the council must consider whether the scheme preserves or enhances the area’s character. A listed building also needs listed building consent for works affecting its character, inside or out. Applications without a heritage statement explaining that impact are easy to refuse.
Conservation officers usually focus on materials, rooflines, window patterns and anything visible from the street. Our guide to extending a house in a conservation area covers what London boroughs typically accept.
8. Missing or unclear information
An application can be refused simply because the council cannot assess it. Common gaps are inaccurate existing drawings, neighbouring windows left off the plans and an unclear red-line boundary. Missing reports, such as a heritage statement, tree survey or flood risk assessment, are another.
Ask the council for its local validation checklist before you apply. A complete, accurate set of drawings is the cheapest refusal-prevention measure there is.
9. Flood risk and drainage
Extensions in a flood zone usually need a flood risk assessment with the application. Without one, or where the extension would make flooding worse, the council can refuse. In London this applies along the Thames and its tributaries, and in areas at risk of surface water flooding.
Basement and lower-ground extensions face the most scrutiny. Floor levels, flood-resilient construction and how rainwater leaves the site are the usual points to address.
10. Trees, wildlife and parking
Trees with a Tree Preservation Order are protected, and so are most trees in conservation areas. An extension whose foundations would damage roots can be refused without an arboricultural report showing how the tree will survive. Bats in roof spaces can also hold up a loft conversion until a survey is done.
Parking and highway safety matter less for most rear extensions. They can be decisive where a scheme removes off-street parking or builds out at the front.
What can’t a council refuse planning permission for?
A council cannot refuse planning permission because a neighbour will lose a view or because their property might fall in value. The Planning Portal lists both as issues that are not material planning considerations.
The number of objections does not decide an application either. One well-argued objection about light carries more weight than many letters about matters planning cannot control.
Building Regulations and party wall matters are separate regimes. Structure, insulation and fire safety are checked through Building Regulations approval, not the planning decision. The difference is explained in our article on Building Regulations vs planning permission.
Which refusal reasons can be fixed, and how?
| Refusal reason | Changes that often overcome it |
|---|---|
| Loss of light to neighbours | Lower boundary wall, sloping roof on the neighbour’s side, reduced depth |
| Overlooking | Obscure or high-level glazing, rooflights, no roof terrace |
| Overbearing scale | Step the extension in from the boundary, shorten it, lower the parapet |
| Poor design or bulk | Smaller dormer set in from the eaves and party walls, better matched materials |
| Street character or heritage | Reduce what is visible from the street, add a heritage statement |
| Missing information | Full survey-based drawings and the reports on the local validation checklist |
Refusals based on the principle of development, such as a mansard where the borough’s policy rules mansards out on that street, are much harder to fix with design changes.
What happens if planning permission is refused?
If planning permission is refused, you have three realistic options: amend the scheme and submit a new application, appeal to the Planning Inspectorate, or build something smaller under permitted development. You can also do nothing and keep the house as it is. Starting work on the refused scheme is not an option, because the council can take enforcement action.
Read the decision notice and the officer’s report
The decision notice lists each reason for refusal and the policies the council says the scheme breaches. The officer’s delegated report, usually published on the council’s planning website, explains the reasoning in more detail. The report often reveals which elements were acceptable and which single issue tipped the decision.
Ask the case officer what would make the scheme acceptable. Some will answer in writing; others will point you to the borough’s pre-application advice service.
Amend the scheme and resubmit
For most householder refusals, amending and resubmitting is quicker than appealing. You can change the design to answer every reason for refusal, which an appeal does not allow.
The “free go” no longer applies in England. Councils used to waive the fee for a revised application from the same applicant within 12 months of a refusal. That exemption was removed in December 2023, and the transition period has ended. A resubmission now costs the full fee: £548 for a householder application in England from 1 April 2026. Fees rise each April in line with inflation.
Appeal to the Planning Inspectorate
You can appeal a householder refusal to the Planning Inspectorate within 12 weeks of the date on the decision notice. The gov.uk householder appeal guidance sets out the process. Late appeals are not accepted.
- If an enforcement notice was served on the same development within the previous two years, the deadline can be as short as 28 days.
- If the council fails to decide your application within the statutory period, usually eight weeks for householder schemes, you can appeal for non-determination within six months of that period ending.
- For householder appeals decided on written evidence, the median time from valid appeal to decision was 12 weeks in June 2026, according to Planning Inspectorate figures.
- If you believe the Inspector made a legal mistake, you have six weeks from the appeal decision to challenge it in the High Court.
The rules tightened for applications submitted on or after 1 April 2026. Under the new procedural guide, most appeals follow an expedited written process. You generally cannot submit evidence the council did not see, and you cannot change the scheme at appeal. Neighbours cannot comment afresh at that stage either, although the Inspector still considers comments made on the original application.
In practice, appeal only when you believe the council was wrong about the scheme as submitted. If the refusal identified a genuine problem, a revised application is the better route.
Consider permitted development instead
Some refused schemes can be scaled back to fit permitted development rights, which need no planning application at all. Houses usually have these rights; flats and maisonettes do not, and Article 4 directions can remove them. Our guide to permitted development for extensions and loft conversions explains the limits. A Lawful Development Certificate confirms the position before you build.
Should you appeal or resubmit?
| Amend and resubmit | Appeal | |
|---|---|---|
| Best when | The refusal points to a fixable design issue | You believe the council misjudged the scheme as submitted |
| Can you change the design? | Yes | No |
| Council fee | Full fee (£548 householder, England, from 1 April 2026) | No new application fee |
| Deadline | None | 12 weeks from the householder decision notice |
| Who decides | The same council | An independent Planning Inspector |
The two routes can run side by side. Some homeowners lodge an appeal to keep the original scheme alive while a revised application goes through the council.
How can you avoid planning permission being refused?
The best way to avoid a refusal is to design to the borough’s policies from the first sketch, not to adjust after the decision. Most of the reasons above can be checked before you submit.
- Read the borough’s extension guidance. Depth, height and dormer rules vary between neighbouring boroughs.
- Search approved applications on your street. Recent approvals show what the council accepts and give you precedents to cite.
- Check designations. Conservation areas, Article 4 directions, listed buildings, protected trees and flood zones all change what is needed.
- Use pre-application advice for borderline schemes. Many councils charge for it, and the advice is not binding, but it can carry weight in the later decision.
- Talk to your neighbours early. Sharing drawings before you apply often heads off objections about light and privacy.
- Submit a complete application. Accurate measured drawings and the reports on the local validation checklist avoid refusals for missing information.
We have worked on more than 1,750 London projects since 2007, and we prepare planning drawings and applications as part of our design phase. Our checklist on how to prevent planning permission refusal goes through the preparation in more detail.
Planning refusal: frequently asked questions
How many times can a planning application be refused?
There is no limit on how many times you can apply, and no limit on refusals. Each new application is decided on its merits, but councils can decline to consider repeat applications that are essentially the same as recently refused or dismissed schemes.
Does a planning refusal stay on the property’s record?
Yes. Refused applications remain on the council’s public planning register, and previous decisions on a site are a material consideration in later applications. A refusal does not stop a better-designed scheme from being approved.
Can I claim costs if I win a planning appeal?
You can apply for an award of costs if the council behaved unreasonably and that cost you money. Winning the appeal does not entitle you to costs on its own. The council can also apply for costs against you.
Can I start building while I appeal?
No. Building the refused scheme before an appeal is allowed leaves you open to enforcement action and the cost of removing the work.
If you are planning an extension or loft conversion and want to know how your borough is likely to view it, book a free consultation with our team.
