Do I Need Planning Permission for My Crawley Extension?

 

One of the first questions Crawley homeowners ask when considering an extension is whether they need planning permission. The answer affects your timeline, budget, and what you can realistically build. The good news is that many extensions fall within permitted development rights, allowing you to build without a formal planning application. However, the rules have conditions and limits that must be understood.

As builders who have completed extensions across Crawley for years, we help homeowners navigate planning requirements regularly. This guide explains when you need planning permission, when permitted development applies, and how to check your specific situation before committing to your project.

 

Understanding Permitted Development

Permitted development rights allow homeowners to carry out certain building works without applying for planning permission. These rights exist to enable reasonable home improvements without burdening the planning system with applications for every minor alteration. For extensions, permitted development covers a significant range of projects, but specific conditions must be met.

The key principle is that permitted development has limits on size, position, and appearance. Stay within these limits and you can proceed without planning permission. Exceed them and you need formal approval from Crawley Borough Council. Understanding where your project sits relative to these limits determines your route forward.

It is important to note that permitted development applies to houses. Flats and maisonettes do not have the same permitted development rights for extensions, meaning most work requires planning permission. If you live in a flat, assume you need planning approval for any external alterations.

 

Permitted Development Rules for Single Storey Rear Extensions

Single storey rear extensions are the most common type built under permitted development. The rules allow extensions that project up to 3 metres from the original rear wall for attached houses like terraces and semi-detached properties, or up to 4 metres for detached houses. These limits apply to extensions with a maximum height of 4 metres.

There is also a larger home extension scheme that allows single storey rear extensions up to 6 metres for attached houses or 8 metres for detached houses. This requires a prior approval notification to Crawley Borough Council. The council consults your immediate neighbours, and if no objections are raised within 21 days, you can proceed. If neighbours object, the council assesses the impact before deciding. This process is simpler and cheaper than full planning permission but does involve council notification and neighbour consultation.

For single storey extensions to qualify as permitted development, additional conditions apply. The extension must not cover more than half the garden area. The materials used for the exterior should be similar in appearance to the existing house. The extension must not be higher than 4 metres, and eaves must not exceed the height of the existing house eaves. No part of the extension can be forward of the principal elevation facing a highway.

 

Permitted Development Rules for Double Storey Extensions

Double storey extensions have tighter permitted development limits. They can extend up to 3 metres from the original rear wall regardless of whether your house is detached or attached. The extension must be at least 7 metres from the rear boundary. The roof pitch must match the existing house as closely as practicable. No windows or other openings can be installed in upper floor side elevations unless they are obscure glazed and non-opening below 1.7 metres from floor level.

These restrictions mean that double storey extensions often require planning permission in practice, particularly on smaller plots where the 7 metre boundary distance cannot be achieved or where the 3 metre projection limit does not provide the space needed. Many Crawley properties, especially in established areas like Pound Hill, Three Bridges, and Ifield, have gardens where achieving the 7 metre distance is challenging.

 

Side Extensions Under Permitted Development

Single storey side extensions can be built under permitted development provided they do not exceed 4 metres in height and are no wider than half the width of the original house. The extension must not extend beyond the front elevation of the original house facing a highway. Materials should match the existing property in appearance.

Two storey side extensions generally require planning permission. Permitted development does not allow two storey extensions within 2 metres of a side boundary, which rules out most side extension scenarios. If your property has significant space to the side and the extension would sit more than 2 metres from the boundary, permitted development may apply, but this situation is relatively uncommon. Most two storey side extensions in Crawley require a planning application.

 

When You Definitely Need Planning Permission

Several situations require planning permission regardless of the extension size. If your property is a listed building, you need both planning permission and listed building consent for most alterations. Listed buildings in Crawley are relatively rare but do exist, particularly older properties in the historic High Street area and surrounding villages.

If your property is in a conservation area, permitted development rights are more restricted. Front extensions and side extensions visible from a highway require planning permission. Cladding and certain other alterations that would normally be permitted also need approval. Crawley has several conservation areas including parts of the town centre, Worth, and some older residential areas.

If your home has had permitted development rights removed by a planning condition, known as an Article 4 direction, you may need permission for work that would otherwise be permitted. This sometimes applies to newer housing developments where the council wanted to maintain consistent appearances. Check your property’s planning history or title deeds for any such restrictions.

If your property has already been extended, previous extensions count toward permitted development limits. The limits apply to the original house, meaning a house that has already been extended may have little or no remaining permitted development allowance. The original house is defined as the house as it was built or as it stood on 1 July 1948, whichever is later.

 

How to Check Your Permitted Development Rights

Before assuming your extension qualifies as permitted development, take steps to verify your position. Start by checking whether your property is in a conservation area or is a listed building. This information is available on Crawley Borough Council’s website or by contacting their planning department.

Review your property’s planning history to identify any previous extensions and any conditions that might restrict permitted development. Planning history is searchable online through the council’s planning portal. Check your title deeds or contact the Land Registry if you suspect restrictions may apply.

Measure your proposed extension carefully against the permitted development limits. Consider all the conditions, not just the projection distances. Remember that limits apply cumulatively with any previous extensions to the original house.

If you want certainty, apply for a Lawful Development Certificate from Crawley Borough Council. This formal confirmation that your proposed work falls within permitted development provides legal protection and can be valuable when selling your property. The application costs less than a full planning application and typically takes around eight weeks for a decision.

 

The Planning Permission Process in Crawley

If your home extension requires planning permission, the process is straightforward though it does add time and cost to your project. A householder planning application to Crawley Borough Council currently costs around £250. You will need drawings showing the existing and proposed layouts, elevations, and site plan. Many homeowners use an architect or architectural designer to prepare these documents.

Once submitted, the council has eight weeks to determine most householder applications. They consult neighbours, assess the proposal against planning policies, and consider any objections received. The majority of reasonable extension proposals receive approval, though conditions may be attached regarding materials, hours of construction work, or other matters.

If your application is refused, you can appeal to the Planning Inspectorate or submit a revised application addressing the reasons for refusal. Often, negotiation with planning officers before or during the application process helps achieve an acceptable design.

 

Building Regulations Are Separate

Planning permission and building regulations are different requirements that serve different purposes. Planning permission controls what you can build and how it affects neighbours and the area’s character. Building regulations ensure that construction meets safety and performance standards.

Almost all extensions require building regulations approval regardless of whether planning permission is needed. This covers structural stability, fire safety, insulation, ventilation, drainage, and electrical safety. You can obtain building regulations approval through a building control application to Crawley Borough Council or by using an approved inspector.

Do not confuse the two requirements. An extension that qualifies as permitted development still needs building regulations approval. Equally, building regulations approval does not mean you have planning permission. Both must be satisfied for your extension to be fully compliant.

 

Common Crawley Extension Scenarios

Based on our experience building extensions across Crawley, certain scenarios arise frequently. The typical 1930s semi-detached houses found in areas like Three Bridges and Southgate often suit single storey rear extensions up to 3 metres under standard permitted development or up to 6 metres under the larger home extension scheme. These extensions typically create open-plan kitchen-diners opening onto the garden.

The newer estates in Maidenbower, Bewbush, and Broadfield feature houses that may have more restrictive covenants or planning conditions. Always check for restrictions before assuming permitted development applies. Some of these developments had permitted development rights removed to maintain the estate’s planned appearance.

Double storey rear extensions on Crawley properties frequently need planning permission due to the 7 metre boundary rule. However, approval rates are generally good for well-designed schemes that do not significantly impact neighbours. The planning application process adds around eight weeks to your project timeline but should not deter you from the extension you need.

 

Get Expert Advice on Your Crawley Extension

Understanding planning requirements is an important first step, but there is no substitute for professional advice tailored to your specific property and project. We help Crawley homeowners navigate planning considerations as part of our extension service, advising on what is achievable under permitted development and when a planning application makes sense.

Our experience with Crawley Borough Council’s planning department and knowledge of local housing types means we can often identify the best route forward quickly. We can advise whether a Lawful Development Certificate is worthwhile, help you understand your options if planning permission is needed, and design extensions that maximise your space within whatever constraints apply.

Contact us for a free consultation to discuss your extension plans. We will assess your property, explain the planning position, and provide clear guidance on the best approach for your Crawley home.

Get in touch today to discuss your home extension project.