JM Construction Blog

Garage Conversion: Costs, Timing and Major Steps

Written by James Murdoch | Aug 4, 2023 10:00:00 AM

A garage conversion is a cost effective way to increase the square footage of your home without the hassle and expense of building an extension. If yours is more frequently used to park unwanted junk than your car, read on for our at-a-glance garage conversion guide. 

What Is a Garage Conversion? 

A garage conversion involves turning your garage into living space, whether it’s an extra bedroom or bathroom, a home office, gym, playroom or bigger living room or kitchen. The possibilities for this home renovation are endless.  

 

 

Why Should You Convert Your Garage? 

A garage conversion is easier, quicker, cheaper and less disruptive than other types of extension as it doesn’t involve building a new structure. There’s also no need for you to move out for the duration or give up garden space. Best of all, it’s often easier to get planning permission for a garage conversion than an extension and, in some cases, you can even go ahead without it.  

The options for what you can do with the space depend on the size and type of garage you have. If it’s attached to the house, just knock down the dividing wall to extend the living room or kitchen, or install a door for access to a new bathroom, bedroom or study. 

If it’s detached, don’t despair as it can be joined to the main building. Or, if it’s large enough, you may want to keep it separate and create a self-contained in-law or guest suite.  

A double garage gives you the most options for conversion to useful space and maybe even multiple rooms. Or you could have the best of both worlds by partitioning it and keeping one parking space. You’re a bit more limited with a single garage, so it’s best to focus on creating a single-purpose space.   

A high quality garage conversion that improves liveability should add value to your home, though how much depends on what you do. Remember, downstairs bedrooms and bathrooms are less desirable than upstairs, and future buyers may be less enthused than you about a home gym or cinema. Most importantly, you’ll be giving up desirable secure off-street parking so check with an estate agent to see how this could impact value and weigh up the pros and cons first. 

 

 

How Much Does a Garage Conversion Cost? 

How much a garage conversion costs depends on the size, whether it’s attached and how you plan to use the space. Joining a detached garage to the main house involves more structural work, and rooms like kitchens and bathrooms are more complex jobs than others. You’ll also want to spend more on a higher quality renovation for living space than on something like a gym.  

Attached single garage conversions start at around £6,000, versus £15,000 for a detached version. An attached double will cost anywhere from £12,000-£30,000. 

 

How Long Does a Garage Conversion Take? 

A garage conversion takes 6 to 10 weeks for an attached single and 10 to 12 weeks for an attached double. 

 

 

Garage Conversion Planning Permissions

Apart from any changes to the front of the building, and external windows and doors, garage conversions generally involve internal work so may be covered by Permitted Development Rights (PDRs), meaning you don’t need planning permission. Exceptions include listed buildings, Conservation Areas and the creation of independent living space.  

Note, however, that PDRs are sometimes removed for garage conversions on certain properties like new housing developments. Nor do they apply to flats or maisonettes. Always check with your local planning authority before starting work.   

Even if you don’t need planning permission, you need to apply for a Change of Use under Building Regulations to convert a garage to living space. Plus, the work will need to be inspected and certified by your local Building Inspector. This ensures the conversion meets certain standards regarding thermal and acoustic performance, fire safety, drainage and electrics, as well as specifications regarding windows, doors and internal and external walls. For more complex conversions, you may need to get plans drafted and inspected in advance

You can save yourself building inspection fees by hiring a contractor registered under the Competent Person Scheme as they can self-certify their work.