How to convert a loft

Updated February 21, 2017

A loft conversion doesn't just increase the value and enjoyment of your home, it also creates new living space from an existing part of your home. Whether it is a new bedroom for your children or office space for a home business, knowing how to convert a loft can mean a whole new lease of life for your house.

Measure the height of your attic, its length and its width, plus the space for a new staircase. Not all the space in the attic will be usable because of the way the roof slopes. Draw a floor plan of the attic. Mark on it where your staircase is and decide where to fit lights and plug sockets. Decide on whether to add dormer windows (which stick out through the roof) or standard windows. Mark these on the plan also.

Reinforce the attic floor. To do this, you will need to remove any existing floor slats or panels to give you access into the roof. Install new support joists so the attic can bear the increased weight of people and furniture. You may wish to employ a contractor to deal with this part of the conversion. Lay new floor boards.

Purchase and install windows. If you are using dormer windows, this will require tile removal and cutting a hole in your roof followed by some woodwork and bricklaying to build up the extension of your existing walls so the window is fully supported. Consult a contractor if you do not know how to do this yourself.

Install joists from floor to ceiling to support new walls. Unless you are using the entire length and width of the attic (in which case you can go on to simply panel and plasterboard the roof as it stands) you will need to add joists and panels to give you new walls. Install the wiring for lights and electrical sockets before plastering, to prevent extra work. You may wish to employ an electrician for this.

Purchase and install a permanent staircase to give access to your new loft conversion. A large selection of staircases can be bought from builders' merchants, so shop around for one that suits you. Once this is installed (which is best done while your plastering is drying as that takes a while), you are all set for decorating the new room.


Before you begin ordering materials for your loft conversion, it is best to check for bats. UK law makes it illegal to disturb a bat colony, so if bats are resident in your attic, you will not be able to get planning permission for your loft conversion. Save yourself time and money by checking first.


Planning permission varies based on exactly what you will be doing with your loft conversion. Because failing to gain the correct level of planning permission can mean you have to remove any extensions, including your loft conversion, it is best to consult your local council's planning department for advice and any necessary application forms before purchasing materials.

Things You'll Need

  • Tape measure
  • Reinforced floor joists
  • Plasterboard
  • Electrical wire
  • Lights
  • Electrical sockets
  • Staircase
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About the Author

Based in the United Kingdom, April Kohl has been writing since 1992, specializing in science and legal topics. Her work has appeared on the Second Life News Network website and in British Mensa's "LSQ" magazine. Kohl holds a Bachelor of Science in physics from Durham University and a diploma in English law from the Open University.