What is the Cost of a Garage Conversion in 2018

Converting your existing garage into a new living space is a cost-effective way to extend your home and provide extra space for you and your family.

Many people who have a garage use it mostly for storage. When you consider the cost of property, this might not make much sense. You could easily convert your garage into extra living space for you and your family. A garage conversion is a relatively simple and cost-effective option.

Why choose a garage conversion?

The cost of converting your garage will be much less than building a new extension or moving to a new house, so it is worth considering if you need extra space and have a garage that is underused.
Converting your garage to a living space can also add value to your house. Some experts suggest that a well-designed space could add as much as 10%. In addition, converting a garage does not usually require planning permission so this keeps costs down and makes it hassle-free.

What does a garage conversion cost?

Converting a garage is much less expensive than creating a new extension from scratch as there is no need for foundations, brickwork or a new roof. A simple garage conversion would cost approximately £5,000 to 7,000 whereas a brand new three-by-four metre extension could easily cost double that figure.

What could you use your new space for?

You can create whatever type of space you need including a playroom, office, kitchen or even more than one room such as a bedroom with en-suite.

The following information will help you to plan and cost your garage conversion

What work will be required and how much will it cost?

The cost of your garage conversion will depend on the existing structure and what you want to achieve.
Converting an integral garage is simple and easy to do as the existing structure will already be suitable as a living space. If your garage is external to the house, then a little more work may be required to bring it up to the standard required. For example, it may need new internal walls, insulation and a new floor.

If you are planning a simple new living room or playroom then costs will be quite low. A conversion to a kitchen or bathroom will involve more plumbing and wiring work and will cost more.

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There are several stages of work that will need to be undertaken to create your new room. If your conversion is a simple one, some of these jobs may not be required.

Building regulations

  • While planning permission is not usually required for a garage conversion your new room will need to meet building regulations.
  • The conversion will need to be inspected at intervals and, upon approval, a certificate of completion will be issued.
  • This is a relatively simple process but there is a fee of around £300 – £600.

Removal of garage door

  • You will, of course, need to remove the garage door and either block up the hole or install a window.
  • To remove a garage door, block up part of the opening and install a window will cost around £1,300 £1,500.

Installing doors and windows

  • If you have blocked up the garage opening, you may need to install or replace a window elsewhere.
  • You may also want to change the internal door or move it to a more convenient location.
  • A new door or window will cost around £500 – £600 but you should allow more if a new opening is required.

New Flooring

  • Your existing garage floor is likely to be uneven and damaged, so you should factor in the cost a new one
  • Pouring a new concrete slab will cost around £1000.
  • In addition, depending on the age of the structure, a damp proof course may be required.
  • You should also factor in the cost of the new floor finishes such as wood flooring, tiling or carpet.

Walls and ceilings

  • If your garage is integral to your house, then the walls and ceiling may be suitable as they are.
  • Plastering of existing walls may be required to provide a clean smooth finish for decorating and this would cost around £500.
  • An external garage will need insulation to keep it cosy and warm and reduce heating bills.
  • If you are dividing the room or converting an external garage, you may need a structure of internal stud walls. If you require stud walls you should allow around £750 per wall.


  • Your garage may well already have electricity, however, you will probably still need extra plug sockets and light fittings.
  • Your new room will also need some form of heating installed. Installing an additional radiator connected to your existing system would cost around £200
  • If you are converting your garage into a kitchen or bathroom you will also need to factor in all the wiring and plumbing required.
  • The cost of utilities can vary depending on the final use of the room. Installing a new electric socket would cost around £100. However, wiring and plumbing for a kitchen could be closer to £1000.

Additional extras

If you choose to use a designer or architect to help you make the best use of your space than you should add their fees to your build budget.

While the above list includes the basic requirements, there may be additional costs depending on the use of the room and the finishes required. For example, if you want hardwood windows and doors these will cost more than basic PVC.

You might also like to include extras such as roof lights, underfloor heating or fitted furniture.


A garage conversion is the simplest way to create a space that enhances your home and adds to its value quickly, easily and with less expense than a conventional extension.