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How to plan a rear extension

Image of a rear extension in the home of @85_wf

How to plan a rear extension

A rear extension extends out from the back of your home. You’ll sacrifice some of the garden but in return you’ll add value and internal space to the property. Read on to find out more.

Do I need planning permission for a rear extension?

Not necessarily, provided the extension meets certain conditions. For example, you can extend a detached property by eight metres to the rear if it’s a single-storey extension and six metres to the rear if it’s a semi-detached or terraced house. For further details, head over to Planning Portal.

Be aware that regardless of the size of the extension you want, if your home is in an area of outstanding natural beauty or a conservation area, you may need to apply for planning permission. This could also be the case if your property is listed. Speak to an architect or consult your local council directly if you’re unsure.

Image of a rear extension courtesy of @plykeakitchens
Image: Plykea.
Does my rear extension need building regulations approval?

The majority of single-storey rear extensions need approval under building regulations. Typically, the areas of work that must meet the requirements of the regulations include doors and windows, drainage, electrics and walls (both external and internal). There are also requirements to meet if you’re adding a kitchen, bathroom or roof. Once again for more on this, take a look at Planning Portal.

What type of building regulations application do I need for a single-storey rear extension?

There are two possible routes for obtaining building regulations approval: a building notice or a full plans application. If the work you’re planning isn’t complex, you can submit a building notice to your local authority. Work can start almost immediately and you won’t need to supply detailed drawings for approval.

If you need to check that your plans meet building regulations before work begins, submit a full plans application to your local authority. Make sure you do this well in advance of when work is due to start on site. While this process takes longer than a building notice, the benefit is that potential problems can be addressed before work begins.

Image of a rear extension in the home of @houseofhaz
Image: @houseofhaz.
What do I need to know about party walls when planning my rear extension?

If you’re planning to dig foundations close to a neighbour’s property (within three or six metres, depending on the depth of the new foundations), you’ll probably need a party wall agreement.

Have a chat with your neighbours before you kick this process off: it could make them more amenable to the works. Then serve them with a party wall notice. You can download free letter templates (which often include letters of acknowledgement for neighbours to complete and return) from the HomeOwners Alliance. Your neighbours will have 14 days to respond in writing. If you’re concerned about the risk of disputes further down the line, you can appoint a party wall surveyor for a flat fee.

I’ve served a party wall notice on my neighbours but they’re refusing to sign it. What can I do?

If you can’t reach an agreement with your neighbour, you’ll need a party wall award. Here, both you and your neighbour appoint an agreed surveyor to act impartially. He or she will produce a legal document that details the work being done and the rights and responsibilities of both parties.

How can I bring natural light into my single-storey rear extension?

Roof lights will bring plenty of light into your rear extension. You can also use glazing to open up the space, blurring the boundary between inside and out and making your home feel bigger even when the doors are closed. It’ll allow more fresh air to flow through too. Once you start looking at glazing, you’ll see you have plenty of choice. Think about French windows or pocket, pivot, sliding or bi-folding doors. To find the style that’s right for you, check out my buyer’s guide to patio doors.

I want to create a seamless connection between my new rear extension and my garden. How can I achieve this?

Why not run the same flooring inside and out? This will link the spaces visually and lengthen the space. Porcelain tiles are a great way to do this as they can withstand a range of weather conditions and are easy to maintain. A word of caution: make sure the porcelain tiles you choose are suitable for exterior use.

You could also use natural stone tiles inside and out – just make sure the ones you select are frost resistant and have adequate slip resistance. Also, they’ll need sealing regularly to stop them soaking up too much water. If you think the upkeep of a natural stone will be too much for you to take on, I’d advise you to go for a porcelain alternative.

Image of a rear extension courtesy of @sheratoninteriors
Image: Sheraton Interiors.

Featured image: A wonderful light-filled rear extension in the home of Katie and Sunny of @85_wf.

Want more? Recently we’ve put together a whole series of blogs on home renovation. Make sure you check out the others here to help you plan your project.