A Step-by-Step Guide to Installing Internal Doors

A Step-by-Step Guide to Installing Internal Doors in the UK

Installing internal doors is a practical and rewarding DIY project that can significantly enhance the aesthetics and functionality of your home. Whether you're replacing an old door or fitting a new one, this guide will walk you through the process of installing internal doors in the UK, from preparation to finishing touches.

Tools and Materials Needed:

  • New internal door
  • Hinges (usually 75mm or 100mm)
  • Screws (typically 25mm or 30mm for hinges)
  • Screwdriver or drill
  • Chisel
  • Tape measure
  • Spirit level
  • Hand plane (for trimming the door if necessary)
  • Door handle set (including latch and strike plate)
  • Pencil
  • Sandpaper
  • Paint or varnish (optional)

Step 1: Measure the Doorway

Before purchasing your new door, measure the existing doorway to ensure a proper fit. Measure the height, width, and depth of the door frame. Standard UK internal doors typically come in heights of 1981mm (78 inches) and widths ranging from 610mm to 838mm (24 to 33 inches), but custom sizes are also available.

Step 2: Choose Your Door

Select a door that matches your measurements and complements your interior decor. Doors come in various styles, such as panelled, flush, glazed, and moulded. Ensure the door's thickness is compatible with your frame and hinges.

Step 3: Prepare the Door

If your door requires trimming to fit the frame, use a hand plane or saw to adjust the height and width. Be sure to remove equal amounts from both sides and the bottom to maintain symmetry. Sand the edges smooth after trimming.#

Step 4: Mark and Cut Hinge Recesses

Place the door in the frame and use a pencil to mark the positions of the hinges on both the door and the frame. Typically, hinges are placed 150mm from the top and 200mm from the bottom. Use a chisel to create shallow recesses (mortises) in both the door and the frame for the hinges to sit flush.

Step 5: Attach the Hinges

Screw the hinges into the recesses on the door first, ensuring they are flush with the edge. Once secured, lift the door into place and screw the hinges into the frame. It’s helpful to have someone assist in holding the door steady during this step.

Step 6: Fit the Door Handle

Mark the position for the door handle and latch according to the manufacturer’s instructions, typically around 1 metre from the bottom of the door. Drill the necessary holes for the handle and latch mechanism. Fit the latch into the edge of the door and secure the handle on both sides.

Step 7: Install the Strike Plate

Close the door and mark where the latch hits the frame. Chisel out a recess for the strike plate and screw it into place. Ensure the latch fits smoothly into the strike plate recess when the door is closed.

Step 8: Check and Adjust

Test the door to ensure it opens and closes smoothly. If the door sticks or doesn’t close properly, make adjustments by sanding or planing the edges as needed. Use a spirit level to check that the door hangs evenly.

Step 9: Finish the Door (Optional)

If desired, paint or varnish the door to match your interior decor. Sand the door lightly before applying the finish to ensure a smooth surface.

Tips for Success:

  • Always measure twice to ensure accuracy before cutting or drilling.
  • Use a sharp chisel for clean and precise mortises.
  • If installing multiple doors, work on one door at a time to avoid confusion.
  • Protect your flooring and work surfaces by using dust sheets or tarps.


Installing internal doors is a manageable DIY task that can greatly enhance the appearance and functionality of your home. By following these steps and taking your time to ensure accuracy, you can achieve professional-looking results. Whether you're a seasoned DIY enthusiast or a beginner, this guide will help you successfully install internal doors in your UK home.

Happy DIY-ing!