Window extensions

Garage Conversion Guide

The Sterlingbuild Guide to Garage Conversions

The list of possibilities available from a garage conversion are endless. An above-garage extension or garage conversion can add both space and value to your property. Here is what you need to know.


Why you should convert your garage

If you are scratching your head trying to find extra living space but don’t want to move home or change the current appearance of your house, a garage extension could be the answer to your prayers.

Whether attached or detached, building an extension on top of your garage or converting your existing garage can provide you with a brand new bedroom that could finally put an end to your childrens’ eternal argument of whose side of the room belongs to who.

Converting a garage into a room has the potential to add serious value to your home, with an overall price increase of 20% not uncommon for households that have built an upwards extension or undergone a double garage conversion, and a 10 to 15% rise for those who have converted their current space. 

FAKRO roof windows for garage and loft conversion
VELUX pitched roof windows with red blinds for loft conversions

Garage conversion ideas

If you are converting your garage into a living space and want the room to be filled with natural sunlight to make it welcoming for its new occupant, you could not go wrong roof windows from ECO+ and RoofLITE, value for money windows that offer most of the same quality spec as better known competitiors.

An above-garage extension gives you free rein over a plethora of roof windows, also available from FAKRO, and VELUX. Though they might not offer quite the same views as when placed high up in a loft, they are the perfect means of making your garage a healthy and fully insulated space

Remember to consider purchasing blinds for your new room for better control of the incoming daylight. See our Blinds Buying Guide for more information.   

What is your garage becoming?

The current size of your existing garage will have a large baring on how far you can go with your garage renovation. The size will also have an effect on how much money you will have to spend on building work. 

Remember to think about what will be going on the floor of your new room. If you are planning on bringing in heavy gym kit or a bath for a new en-suite, it is essential that you get the structure of the flooring right first time.

If you are planning to build a new bedroom for one of the children or another family member, it is important to think about if you will need a staircase or ladder fitted. In the case of a detached garage conversion, this will likely be a necessity, but if your garage is attached, it wont.

Bare in mind, however, if you don’t need to include a loft ladder in your garage because it is attached, access to the new room via the main house might mean having to walk through another bedroom - something far from ideal for many. Shop our range of aesthetically pleasing and robust loft ladders.

climbing a Youngman aluminium loft ladder
VELUX roof windows for garage extension and children's bedroom

How much does a garage conversion cost?

Depending on the size of your existing garage, to built on top of it will usually set you back between £15,000 and £20,000.

If you are simple converting your current garage into a living space, expect to pay between £5,000 and £10,000. For garage conversions, we have a number of quality windows and doors available from REAL that will keep down renovation costs.

To calculate how much your garage extension might cost where you live, click here.

Important things to consider

Before anything else- garage extension planning permission. To avoid having your dreams shattered before work has even began, it is vital that you check whether you will need planning permission before any work is carried out with your local planning authority.

You must comply with all garage conversion building regs related to the floor and walls, ventilation and fire safety. Contact a ‘building control body’ (BCB) to check the building regulations appropriate to your property. This can be done via

As explained in our Single Storey Extension Guide, the Neighbour Consultation Scheme and Party Wall Act also need to be considered before work can get underway.

Visit our Loft Conversion Guide for guidance on who can help with your garage extension.  

FAKRO pitched roof window for loft conversion and garage extension