11 Things To Consider When Planning An Extension







Copy Link

If you love where you live but are lacking in space, extending your home is a fantastic way to solve the problem without the hassle of moving. 

Before you start speaking with architects or builders, here are some things to consider that will help when planning an extension.

If you are thinking about extending in the near future and need some help with where to start with your project, try our renovation advice session.

Renovation advice session

1. What do you want to use the new space for?

It's important to be clear on your requirements when planning an extension, so write a wish list at the outset. 

It might be that you would like a large open plan kitchen, to create a sociable living space. 

Other rooms such as a utility room, study, playroom, guest room or snug might be high up on your list. 

Be really clear with what you want out of your new space before you meet with an architect so you don't want to have any regrets once it's finished. This will also help the architect when designing your extension.

Extension by Lost & Found Architects

2. How long do you plan on living in the property?

When planning an extension, you should take into account whether you plan on living there in the short term or whether you see it as your forever home.

If it is your forever home, then design your extension to suit your needs and style; you can be so much bolder with colours. You may also choose to invest more as you don't plan on recouping the investment.

However, if you plan on moving again after a few years', or indeed it is an investment opportunity, this could shape both the layout and the style. 

You might want to keep the colours neutral with a classic kitchen and flooring so that it would suit a wide audience. You may also be tighter with your budget in order to profit from the extension.

It's worth considering the balance of your new extension. If you are creating a large open plan kitchen with two or three bedrooms, consider adding an extra bedroom as part of the extension to make your home more appealing when it comes to selling in the future.

Extension by Obiter Architects

3. How do you want the new space to look?

Adding an extension is a serious investment, so it's important that you get it right. Do you want a modern style with lots of glass, or do you want the extension to blend in seamlessly with your property and style of finish? 

Spend time on Pinterest, Instagram, our website and magazines, pulling together your ideas on how you would like it look. Order lots of samples of flooring and paint to make sure you choose the right look for your home.

When you are choosing to work with an architect, it's important to work with one who understands your sense of style, so being clear on what that is in the outset will help.

4. Make sure you consider the impact of light into your home 

If you live in a terraced property and extend to the side, you might block out some of the light to your home. Consider incorporating a roof lantern or glass roof to allow more light in. The more light you get into your home, the more spacious and calm it will feel.

Adding roof lanterns and glazed ceiling are more expensive than a standard roof, however you don't want to have a beautiful new kitchen which is very dark; try and maximise the light as much as you can.

Extension by archangels Architects

5. Do you need to upgrade your plumbing and heating?

When you are planning an extension you need to consider whether your existing heating system will be able to provide for your new home.

If you are adding additional bathrooms it's worth considering changing to a conventional boiler if you have a combi.

You also might want to add in underfloor heating to a kitchen extension. Thinking of these details early on will help when planning an extension as they need to be budgeted for and also should be factored in early in the build process.

6. Be clear on what budget you have

Firstly, get a ballpark figure for how much your extension may cost. Our extension cost calculator will give you a high level figure based on the size, specification, which rooms you are adding and where you live in the country.

Then it's important to work out what funds you have available for the extension. It may be that your extension will cost significantly more than you originally thought, so you can decide whether to do it now or wait. 

Once you are comfortable with your budget, this will determine what you can do in terms of style and finish, which will help your architect when they are carrying out the plans.

Extension by Hough Architecture

7. Be aware of all the relevant permissions and notices

Planning permission is the most obvious permission that you need to consider when planning an extension.

In many cases your extension will be within permitted development, which means you don't need to apply for planning permission. However, this is subject to many things, including the size, style and your particular home and location. To find out more about when planning permission is required, read Your Guide - Planning Permission.

Even if your extension is within permitted development, you will still need building control approval when you are carrying out structural work. Building regulations ensure that your building work meets a minimum standard and building control approval is always required. To find out more read Your Guide - Building Regulations.

Many types of extensions in England and Wales will also require you to serve A Party Wall notice to your neighbours, particularly if you are carrying out work in a terraced or semi-detached home. To find out more read our Expert Advice - Party Wall Act.

It's also worth considering whether you have any trees that may have a Tree Preservation Notice, whether your home has the presence of bats which may be disturbed or if you are carrying out work near a sewer.

8. Consider your neighbour(s) "right to light"

Your extension might be within permitted development and you don't need planning permission, but you still need to be aware of the impact that your extension is having on your neighbours home and particularly their "right to light". 

Every landowner (England and Wales) has the right to receive light through their window and if you seriously block light into their window and their window has been there for more than 20 years, they can take legal action.

Extension by Granit Architects

9. Do your research on contractors

If your neighbours have carried out a similar extension, speak to them and ask for recommendations for builders. Or your architect will be able to recommend some that they have worked with in the past.

Really check out the builders work and make sure it's of the best quality and to your standards. Have a short list of builders so that you are ready to get several quotes. Remember that the cheapest won't necessarily mean the best, so take a step back and think through your choice.

10. Chat to your neighbours!

Even if you don't need planning permission, you still need to make sure your neighbours are on board with your plans to make for a smooth process. Chat to them early on about what you are planning to do so that you can discuss any concerns. It should make life easier when you actually start the work.

You also may need a Party Walls Act 1996 (England and Wales only) consent signed by your neighbours, so it’s worth taking them through your plans at an early stage.

Extension by Unagru Architects

11. Think about the timescales

It could easily take 6-9 months to actually start the build from when you decide you want to go ahead with the extension. Consider what time of year you want the build to start, with summer being a better time with (hopefully!) not as many rain delays and warmer temperatures. Planning this into your schedule might delay the project further but it will make it easier in the long run.

Also consider where you are going to live while the work is being carried out; will you stay in your home or move out temporarily? If you are staying in your house, consider having breaks away to visit family and friends.

The work is likely to take longer than both you and the builder planned, so be patient as it will be worth the extra time!

If you are thinking about extending in the near future and need some help with where to start with your project, try our renovation advice session.

Renovation advice session

Published: January 4, 2023

Join thousands of renovators getting great advice and inspiration right to their inbox

Sign Up

minimum password length is 6 characters
I have read the terms of use along with the privacy and cookies policies.

Sign up with Facebook Sign up with Google

Are you a business? Learn more

Already have a Love Renovate account?

Log In

Are you a registered business with us? Sign in here

Sign in with Facebook Sign in with Google

Don't have an account?

Reset Your Password