How to build a loft conversion

Updated February 21, 2017

When the need arises for more space, one of the most common places to look for it is in the loft. Depending on the size of the home and the pitch of the roof, there is possibly enough room to add living space in the loft. Do plenty of research and talk to friends and neighbours about their experiences if they have already converted their lofts. As in all projects this size, it is best to draw up some plans. This will help determine what type of budget to set for the project.

Clear the loft area where the conversion is to take place. Measure the width and length of the loft to determine how much ¾-inch plywood is needed for the floor.

Cut the ¾-inch plywood with a circular saw to fit on ceiling the joists to cover the entire loft area. Secure them to the ceiling joists with 2-inch deck screws. Next, measure in from the width of the loft to the desired location of the walls and mark the floor. Pop a chalk line on these marks the full length of the loft.

Cut enough 2-by-6-inch lumber to lay end to end the full length of the loft. Do this twice for each wall. These are the top and bottom plates of the walls.

Place a 2-by-6 flat on the floor at the desired wall location. Stand another 2-by-6 on its end and on top of the one on the floor. Place the carpenter's level on the vertical 2-by-6 to be certain it is plumb. Draw a line on the 2-by-6 where it meets the rafters of the roof.

Lay the marked 2-by-6 on saw horses so that the line is facing up. Place a 2-by-6 on its narrow edge and on the line. Draw another line that will make the marked 2-by-6 shorter by 1½ inches. Cut this line with a circular saw. This is a wall stud; use it as a pattern to cut as many studs as needed to go the full length of the loft on 16-inch centres.

Build the walls by securing the studs to the top and bottom plates, using the 3-inch deck screws. Install a stud every 16 inches. Stand the walls up and secure them to the plywood floor and the roof rafters with the 2-inch deck screws. Cover the walls and the bottom side of the roof rafters with plywood or drywall.


It may be necessary to cut the 2-by-6s intended for studs to a length that allows you to stand them on end between the floor and the bottom of the roof decking to mark them properly. If there are no gable vents, you may want to install electric lighting along the ceiling of the loft conversion. Check the building codes for your area for any possible building permits needed before beginning.


Do not leave tools unattended in the presence of children. Do not paint or stain the loft conversion without proper ventilation.

Things You'll Need

  • ¾-inch plywood
  • Circular saw
  • Variable-speed drill
  • Phillips-head screw tip
  • 2-inch deck screws
  • Chalk box
  • Carpenter's level
  • 2 saw horses
  • 3-inch deck screws
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About the Author

Michael Straessle has written professionally about the construction industry since 1988. He authored “What a Strange Little Man,” among other books, and his work has appeared in various online publications. Straessle earned a Bachelor of Arts from the University of Arkansas at Little Rock in professional/technical writing.