Preparation before you start



  1. UPVC windows are not designed to be load bearing, so a lintel may be required above the window. Consult a qualified surveyor or fitter beforehand if you are not sure.
  2. Check the style, handing and size of your window against what you ordered
  3. Before the existing window is removed, check opening sizes and remember any new window should approximately be 10mm smaller in height and width than the brick opening.
  4. Ensure a clean and clear working area around the window, so remove any interior & furnishings.

Removal of Existing Window


  1. Ensure the immediate area is covered with durable dustsheets inside and outside
  2. Use the nail bar/screwdriver to remove all opening sashes
  3. Make sure you are using the heavy duty gloves and goggles to remove the glass in remaining window fixed lights. Carefully crack the glass with the screwdriver or punch with the light hammer. To do this as safely as possible, ensure you start at the top corner from inside the window, then remove the cracked shards and place them into the plastic bin. Ensure all the glass has been removed and proceed to the next step.
  4. Using the Stanley knife on the inside of the window, break the plaster seal around the periphery of the window frame.
  5. Cut through the remaining vertical and horizontal frame members using the crosscut saw and then remove.
  6. Try and minimise the damage to the plaster, brickwork and damp proof membrane as you cut through the outer frame jambs head and the sill of the window frame.
  7. Applying careful application of the nail bar, it should now be possible to lever the framework away from the plaster line with minimum disturbance.


Fitting the New Window



Sill (Where a sill is required)

  1. Place the window sill profile onto the brickwork, such that the up stand is nicely snug against the plaster line of the jambs. You may need to trim the horns to fit around the brickwork.
  2. Using the plastic packers, make sure to level the sill with approx. 5mm clearance between it and the brickwork.
  3. Ensure the sill is secure to the brickwork using the 8 x100mm fixing bolts positioned approx 150mm from each end and at 600mm centres thereafter. Do not over tighten the fixing bolts and check the level.
  4. Run a bead of silicone along the back edge of the sill up stand.
  5. Then using silicone or superglue, secure the end caps into position. The caps may need trimming to size if the sill horns have been cut around the brickwork
  6. Remove all the glazing beads from the window frame and mark them accordingly to make sure that they can be placed back into the original position.
  7. Then offer the new window into position and with the base snug against the sill up stand, ensure a tight seal into the bead of silicone. Clean off any excess silicone. Using the spirit level, ensure the window is positioned vertically and where appropriate is hard up against the plaster line.
  8. Wedge the window into its position by using the plastic packers that are provided.
  9. Ensure that the framework does not bend by over packing
  10. Ensure the vents of the window are open to enable access to the outer frame jambs. Using #8 x 40 posidrive screws, secure the bottom of the window to the sill 150mm from each internal corner and 600mm centre’s thereafter.
  11. Make sure the window jambs are bolted into the brickwork surround using 8 x 100mm fixing bolts 150mm from each corner and at +/- 600mm centre’s thereafter.
  12. It is important to remember that in all cases the screw heads are not standing above as this may interfere when it comes to the glass fitting and positioning. Please note, it is not advisable to attempt bolt fixing in the head of the window as there is the possibility of permanently damaging the structural lintel of the window. The best solution for fixing the head is to use expanding foam, which is available on request.
  13. Finally, close and lock all opening sashes and then check for squareness within the outer frame.

Fitting Glazing



  1. Prior to locating the glass sealed units into the appropriate aperture, it is necessary and important to position 22 x 100 x15 glazing bridges into the frame recess. A small dab of silicone will then secure the packer in place in preparation for the next step.
  2. Position a 28 x 100 x 5 glazing packer on the bottom glazing bridges. In the event of side hung sashes, also glue or silicone an additional 28 x 100 x 5 glazing packer onto the glazing bridge that is opposite the hinge side.
  3. Offer the appropriate glass sealed unit into the aperture and make sure it is resting squarely on the glazing packers. Ensure the glass is central within the opening and then push the glass back into the rebate as far as it will go without using undue pressure.
  4. Only using hand pressure, position additional 2mm glass packers to square up if this is necessary.
  5. Gently unlock and open the sashes to ensure that no binding occurs within the locking system and that no movement occurs between the glass and frame. Slight, minor glass packer adjustments may be necessary to achieve perfect squareness.
  6. Then clip the pre-marked glazing beads back into the original position in the following order; top, bottom and then sides.
  7. Carefully apply a bead of silicone between the outside masonry and window frame periphery, remembering to wipe off any excess.
  8. Similarly, gun a thin bead of acrylic between the inside plaster and window from the periphery. Allow this beading to skin over which will take approximately one hour. Remove all the protective tape from the faces of the window frame, clean where necessary with warm and soapy water.

Finding it difficult? Give us a call 0800 389 5957

If you’re fitting a UPVC window for the first time, we’d like to say well done for getting this far. Do you live in Hampshire, Surrey, Sussex or Kent? Well South Coast are close by, just give us a call and one of our fitters will offer support and assistance.

How difficult is it?

If you have never fitted UPVC windows before the most important step is to ensure the new window will fit within the existing brickwork opening that was left by the old window and to this end the accuracy of the window survey is paramount. If you are still unsure, South Coast Windows fit UPVC windows in Hampshire, Surrey, Sussex and Kent locations.