Extending your home is a great way to add space, enhance your living environment, and potentially increase the value of your property.
In some cases, buying a property that has the potential to be transformed might also be a better solution than finding an empty plot or getting permission to knock down and rebuild.
However, before you call in the builders, it’s crucial to know whether your home extension requires planning permission. In the UK, the process can seem a bit daunting at first, but with some careful preparation and a clear understanding of the rules, you can successfully navigate the process.
Whether or not you need to make a formal planning application for an extension will vary from case to case, depending on a number of factors. So, let’s take a closer look at what does, and doesn’t, need consent. We will also explore overarching planning policies and the key considerations you need to take on board to ensure your project is a success.
Check if You Need Planning Permission
Firstly we’d strongly advise you to fully understand your project and what it is that you’re trying to achieve. Are you building, extending or changing use? This defines what permissions you will need. Every kind of extension – one or two storeys; front, side or back; an addition to the roof, a porch or a conservatory – technically requires planning permission.
However, in some instances, certain home extensions are covered under Permitted Development Rights which effectively means that the Government grants permission, rather than the local planning authority. These rights allow homeowners to extend their properties without the need for formal planning approval, as long as the extension falls within certain limits. However, some areas, such as Conservation Areas, National Parks, or Listed Buildings, have additional restrictions and Permitted Development rights might not apply in these cases.
Key Criteria for Permitted Development:
Before proceeding, it’s essential to check the guidelines. If your home extension exceeds the regulation limits, then you’ll need to apply for planning permission.
The extension should not cover more than half the land around the “original structure” (as it was when it was first built or, in the case of older houses, as it was on the 1st July 1948).
Single-storey extensions must not extend beyond the rear wall of the original house by more than:
- 3 metres for an attached house (such as a terrace or semi-detached house).
- 4 metres for a detached house.
Multi-storey extensions must not extend beyond the rear wall of the original house by more than 3 metres, be higher than the highest part of the existing roof and must be a maximum height of 3m if within 2m of a boundary. There is also the so-called ‘45° rule’ to take into consideration, to ensure your new extension doesn’t intrude on the outlook from certain neighbours’ windows.
A rear extension can’t be projected beyond the side wall of the house (a wraparound extension) to be considered under permitted development, and this is very clear in the official guidance.
Lastly, you must ensure the materials of your extension are similar in appearance to the existing house. For example, if your home has brick walls and a tile roof, then the extension must be the same. However, if you have a mix of materials on your existing house, then this could allow more scope for your design possibilities.
Neighbour Consultation Process – also known as the Larger Home Extension Scheme
If you believe that your three-metre extension is simply not going to create enough space for you and your family, then there is the option to extend up to six metres on a semi or eight metres on a detached property. This is part of what is called the ‘prior approval’ process although it is still part of the Permitted Development legislation.
This isn’t a full-blown planning application, but it does involve submitting a form and basic drawings to your local council, informing them about what you’d like to build. They will then notify your neighbours to see if anyone objects, and if so, whether the objection is valid. Unlike a planning application, the proposal won’t be advertised publicly.
One reason your neighbour may have to object could be the loss of daylight for example. If your extension is considered to be overbearing for your neighbours, it is worth noting your neighbours do have what is known as a “legal right of light”.
If you wish to build on the side of your house, at ground floor, you can extend the full depth from front to back, however the width of your extension cannot be more than half of the width of the existing structure of your house. For example, if the width of the house is five metres, you cannot extend more than two and a half meters. This is regardless of how close this comes to your side boundary; however, you may want to think about whether you’d like to leave room for the side access to your rear garden. Where a side extension is combined with a rear extension, this is a wraparound extension and is not allowed under permitted development.
It really is possible to achieve quite a lot of additional floor space under permitted development, as long as you take consideration of the rules and guidance. Most homes in the UK have these rights, but there are some instances where your property may not have all of these rights, such as:
- Conservation Area or other Protected Area
These are areas where local authorities have put planning controls to protect the character of an area. An example of this would be a conservation area; there are 109 such areas in the Peak District National Park alone.
There are also these examples below too, where homes here may not have these rights:
- Listed Buildings
- Buildings in Areas Of Outstanding Natural Beauty
- World Heritage Sites National Parks
- World Heritage Sites
It is also important to note that in certain areas the PD rights may have fully or partially been removed as a condition of their planning permission. This can include some newer large housing estates, so if you live in a relatively new property, it’s worth checking the planning permission with the house builder.
As this is only a rough guide, you should consult an expert planner or architectural designer before commencing your own project
You may need expert advice that’s tailor made for your unique property and all aspects of planning your extension. One thing most experts will advise is to apply for what’s known as a certificate of lawfulness before you start. This is a request for the local authority to confirm that what you want to do is actually permitted development. If your proposal does fall under PD, they cannot refuse it. It’s also a very useful document to have when selling your house and showing solicitors what work has been done previously.
Submitting A Full Planning Application
If your home extension doesn’t qualify under Permitted Development then you will need to submit a formal planning application, if you are unsure, it might be a good idea to seek pre-application advice from your local planning authority (LPA). This can help you identify potential issues early on and understand what information will be required in your application. Most local councils offer this service, and while there may be a small fee involved it could save you time and money in the long run by preventing refusals or delays.
To submit your full planning application to your LPA, here’s what you will need:
- Completed application form: You can usually find this on your local council’s website.
- Design and access statement: This document explains the purpose of the extension, the design approach, and how it fits within the surrounding area. This is not always required.
- Scaled drawings: You’ll need to provide detailed plans of your property as it currently stands and how it will look with the proposed extension. These include site plans, floor plans, and elevation drawings.
- Site location plan: This shows where your property is located in relation to its surroundings.
Planning Fees
Submitting a planning application incurs a fee, which varies depending on the nature of your project. For householder applications, which cover typical home extensions, the cost is usually around £206 in England, although this may vary slightly in Scotland, Wales, and Northern Ireland. Your local council’s website will have the most up-to-date information on fees.
Await a Decision
Once your application has been submitted, the LPA has eight weeks to make a decision for most straightforward home extension projects. For larger or more complex developments, this period can extend up to 13 weeks. During this time, the council will typically consult with your neighbours and may also notify other relevant bodies, such as environmental agencies, if necessary.
The council will consider several factors while accessing your application, factors such as what impact your extension might have on your neighbours or environment will be taken into account. The appearance of your extension is also significant and your extension should be in keeping with the style and character of the surrounding area.
Keep Neighbours Informed
Keeping good relations with your neighbours is crucial when undertaking a home extension. Even though they don’t have the power to veto your project, their feedback is considered in the planning process. Informing them early, showing them your plans, and addressing any concerns can help avoid objections that might slow down your application.
Receiving the Decision
There are three possible outcomes to your application:
- Approval: If granted, you’ll receive a document outlining the conditions of approval. This might include specifications such as the type of materials to use and will include a timeframe for starting the project.
- Conditional approval: You may be required to make changes or meet specific conditions before beginning the work.
- Rejection: If your application is refused, you can amend and resubmit it, or you may choose to appeal the decision.
If your planning application is refused, or if you disagree with the conditions imposed, you have the right to appeal. Appeals are submitted to the Planning Inspectorate in England. Appeals can take several months, so it’s best to work with your LPA to resolve any issues before taking this step.
Building Regulations Approval
Even if your extension doesn’t require planning permission, it will still need to comply with Building Regulations. These rules ensure that your extension is safe, energy-efficient, and compliant with fire safety standards. You’ll need to submit a separate application for Building Regulations approval, and this process involves inspections at various stages of construction.
Contact our Ecclesall Design team to begin your architectural project
Getting planning permission for a home extension in the UK can seem complex, but by understanding the rules from the beginning the process becomes much more manageable.
Start by checking whether your project qualifies under Permitted Development rights, and if not, ensure your planning application is thorough and complete. Patience and preparation are key to ensuring a smooth process, so be sure to plan ahead.
Get in touch with our friendly people at Ecclesall Design if you are considering an architectural project and would like further advice on the next steps. We have an outstanding success record for achieving planning permission, with a 100% success rate with Planning for building new houses and house extensions. Our team has a practical, hands-on understanding of the building process, and we’ll guide your project through every part of the process, from your initial consultation to successful completion.
