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The Ultimate Guide to Building a Side Extension in Manchester

Many properties in Manchester are perfect for side extension projects, here we will show you how you can build a side extension for your home.

Modern side extension design
Credit @ZCD Architects

Side extensions - like all construction projects - need to be carefully thought out and designed. Furthermore, these designs need to be checked and approved for planning permission and building regulations approval.

So where do you start when building a side extension? Below we've provided a step by step guide through the entire process.

What is a side extension?

Just so that we're on the same page - a side extension is a built extension to your property and normally single or double storey. These extensions are normally seen from the street at the front and from the rear garden. 

Side extensions can come in a few different varieties, some will be simple blocks from the ground, some will sit on top of an existing garage space, others may not touch the ground at all! 

When consider whether a side extension is the best project for you, first list your requirements and what you are looking to get from the project.

Image credit @CoffeyArchitects

Bifold door house extension

Why build a side extension in Manchester?

Side extensions can be very useful to properties in Manchester, here are some common examples :

Provide more bedrooms, bathrooms and living space - side extensions are great for providing additional rooms off of the main corridor without disrupting the existing rooms on your property.

A better insulated house - Side extensions can be a good excuse to provide improvements to the rest of the house through insulation and energy efficient renovation.

Increases the price of your home - By adding 2-3 bedrooms to your home, the selling price will increase significantly. In fact, having planning approval alone can make a noticeable impact on the value of your property.

concrete house extension

How does a side extension cost in Manchester?

The cost of a side extension in Manchester will depend on your design and the existing house. 

This being said, it is reasonable to assume you will spend between £1,500 - £2,100 per square metre, with a single storey side extension totalling £30,000 and a two storey side extension coming in at £55,000 for the construction. 

Be aware that there is also the cost of professional fees and application fees, normally setting aside 10% of the construction cost will be enough to cover these expenses.

Image credit @YARDArchitects

Glass roof house extension

Home Side Extension Construction Calculator For Manchester

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How to Build a Side Extension: Ultimate Guide

Now that you have everything you need to know to plan, your ready to start your project.

Step 1: Make a list of everything you need your side extension to do.

Making a list of the key goals of your project will help when speaking with others who may be conducting work.

It is normally best to list the key rooms first and think about their sizes, then try to find images of projects you like, if you have difficulty defining your plans we offer free advice workshops to make the process easier.

Step 2: Design your side extension / Get your project design by an Architect.

With your list of requirements created, you can now jump into sketching your plans with drawings or commissioning an architect to draw your plans professionally.

The aim will be to have well drafted plans and statements ready for applying for planning permission, an architect can help you do this alongside other services.

Step 3: Apply for planning permission (if you need it)

In Manchester and across the UK many common properties have permitted development rights, this means you do not require planning permission for your side extension. 

You should (or you Architect should) always check whether you require planning permission or not. These will normally be clear depending on the size of your side extension and the materials used. 

Be aware - conservation areas, the green belt and listed buildings do not normally have these rights. If you are unsure about whether you have these rights or not please reach out to us for free advice.

Step 4: Get your side extension design checked for building regulations approval.

It can be tempting at this stage to jump into getting builders onto the property and building. However it is strongly advised to get building regulations approval for your side extension prior to construction.

Building regulation rules cover structural calculations, fire protection and thermal efficiency to name a few. If this is something you are unsure about or need assistance with, please feel free to ask for advice. This will avoid you encountering timely and expensive issues in your project.

Step 5: Have your side extension built / build your side extension yourself

Now that you've gained approval and have the designs checked. You are ready to build!

Finding a builder can be tricky and it is recommended to check quotations and compare to check the price and the terms are reasonable. 

If building yourself, bare in mind what you are able to do yourself and what work is useful to leave to experienced tradesman. For more information on building your project yourself and saving money see our guide on the topic. 


Side extensions provide a fantastic way for you to expand on your existing home, providing lots of new rooms and potential. If you still have questions regarding the best way to proceed with your side extension project, we're here to help, feel free to get in contact with us below. 

Image credit @iqGlass

Modern Glass roof house side extension

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