Constructing a flatpack cupboard

Summary: Learn how to build a flat pack cupboard, fix the side in place, fix the lining and install the runners and door.

These days cupboards can be bought as flatpack self assembly kits. The range available is extensive and varies in quality, but the method of putting this type of cupboard together will be similar regardless of its manufacturer.

In this project we provide general guidelines on how to build a flatpack cupboard in the corner of a room. However, it is important to remember to follow the manufacturer’s instructions particularly in relation to fitting the doors, as different styles of door require very different methods of fitting. Before buying your flatpack cupboard measure the area where it is to be located to ensure it will fit. Modern flatpack furniture is not heavy, but the size of the panels can make it awkward for someone on their own to manoeuvre, so you may need some help.

Position the side panel against the vertical line on the wall and ensure it is at 90°.
When you are sure the panel is vertical, thighten the fixings.

Fixing the side in place

  • From the corner of the room measure to where the side of the cupboard is to be fixed. At this point use a spirit level to mark a vertical line on the wall.
  • Position the edge of the side panel against the vertical line. If the wall has a skirting board or is uneven the edge of the side panel will not fit flush against the wall. If this is the case, you will need to scribe and cut the panel before fixing it in position.
  • Using a try square make sure the panel meets the wall at a right angle (90°). When you are satisfied the angle is correct fix the side panel to the floor using stretcher plates.
  • Use the try square to check the top of the panel is at 90° to the wall.
  • The top of the side panel should now be loosely fixed to the ceiling, fixing the stretcher plates to ceiling joists if possible.
  • With the panel loosely fixed to the ceiling, check that it is vertical with a spirit level. Moving the stretcher plates backwards or forwards can make adjustments to the panel’s position. When you are satisfied the side panel is vertical, tighten the screws.




Use a tenon saw to remove the marked section of skirting board.
Once you are sure it is vertical, screw the lining to the wall.

Fixing the lining

  • From the corner of the room measure along the other wall and mark the position of the cupboard’s front edge.
  • From the front edge mark the width of the lining on the skirting board and using a tenon saw, carefully cut and remove this section of skirting board. The cupboard’s lining will now fit flush against the wall.
  • Position the lining against the wall and check it is vertical with a spirit level as you fix it in position. The lining is screwed to the wall.










When fixing the top runner, make sure you use the correct plugged fixings for the ceiling.
When the doors are gliding smoothly, the bottom rail can be fixed to the floor.

Fixing the runners and door

  • When the side panel and the lining are fixed in position the runners and door can be fitted. First measure the distance between the inside edge of the side panel and the inside face of the lining at the top and bottom of the opening. If the measurements are equal then the opening is square. If not, adjust the position of the side panel by moving it along the stretcher plates.
  • At the top of the cupboard, measure the distance between the inside edge of the side panel and the inside face of the lining then cut the top runner of the sliding door mechanism to the correct size with a hacksaw.
  • Follow the manufacturer’s instructions on positioning and fixing the top runner to the ceiling. The correct plugged fixings must be used for the type of ceiling you have.
  • The bottom runner can now be cut to the same width as the opening and positioned between the side panel and the lining. Do not fix it to the floor at this stage.
  • Once again, follow the manufacturer’s instructions on fitting the doors, as these will vary according to the make of the cupboard.
  • With the doors in position check that they open and close smoothly. When the doors glide smoothly the bottom rail can be fixed to the floor.
  • Before screwing the bottom rail in position use a cable detector to check that there are no cables or pipes beneath the floorboards.

Related projects

Related cost guides