This video nicely shows how timber frame windows are removed and uPVC frames and windows are installed.

Before You Install Your uPVC Window Frames

1) Check if your old timber frame window frame was load bearing. If it was then you will have to install a lintel first because uPVC is not designed to be load bearing.

2) Measure the gap in the wall for height and width and then check this against the measurements of your uPVC window frame. The height and width of the uPVC window frame should be 10mm less then the gap in the wall.

Removal of Existing Window

1) Cover area with dustsheets

2) Use a screw driver to remove all the opening sashes

3) To remove the windows it is easiest to break the glass. Do this from inside the house. Use a light hammer and hit the window at the top. Remember to wear heavy duty gloves for protection.

4) With a stanley knife break the sealing around the window frame.

5) Use a saw to cut through the timber frame both horizontally and vertically and remove.

6) Cut through the outer jams and remove. It should now be possible to remove the remains of the old timber frame without damaging the plaster work or the bricks around the window opening.

7) Use a masonry chisel to remove any accumulation of cement.

Installing the new uPVC window frame

1) Now that the hole is prepared you can add your uPVC cill to the hole. Make sure there is a 5mm clearance between the cill and the gap. Then secure the cill in place with 100mm fixing bolts. The bolts should be placed 600mm apart and 150mm from the edges.

2) Use a silicon gun to add a line of silicon along the vertical parts of the cill.

3) Use silicone or superglue to secure the end caps in position.

4) Wedge the window into position using plastic packers.

5) Secure the window in place with posidrive screws. Place the screws 600mm apart and 150mm from the internal corners.

6) Close and lock all opening sashes. Check that the window is sqaure within the frame.

These are general guide lines to installing uPVC windows. It is a skilled job and should only be attempted by people experienced at D.I.Y.

If in doubt it is best to ring around a few window companies to get a quote for installing uPVC windows. Or get the dealer to include a quote for installation in the price of the windows. Beware of window sales people - they are like car sales people. They are liable to inflate prices for installation to increase their commission fee. Don't be afraid to say 'no' and look elsewhere for a better quotation.