1 Prepare the rough opening. It is extremely important that the opening is plumb and level. The window must set square and level into the finished opening. You can make a template by tracing the window on a piece of cardboard and enlarging the tracing by 5/16" all the way around, to make it the size of the rough opening.

2 Pre-drill the exterior casing.

3 Carefully apply interior extension jambs, if needed.

4 Check the fit, than caulk the back of the exterior casing and place it into the opening, be sure it is plumb and level. Nail or screw the window to the building through the pre-drilled exterior casing.

5 Caulk the perimeter of the exterior casing where it contacts the building. install window flashing to the top edges, as needed.

6 Install interior trim.

7 Fill nail holes and stain or paint the unfinished wood surfaces, inside and out, all surfaces must be finished as soon as possible to prevent warping. Apply a bead of caulk where the glass contacts the exterior trim.

Installation is basically the same as the wood window, with the following additions.

1 The window frame is clad with a durable one piece polymer cladding. The cladding needs no finishing. It is important that the cladding is not nailed randomly, use aluminum or stainless steel screws or nails and fasten through the holes provided, or drill new holes a little larger than shank of the fasteners being used..

2 Cover nailing flanges with siding or trim. Do not nail siding or trim through the window nailing flanges unless through holes pre-drilled a little larger than the fastener shank.

3 Interior surfaces must be sealed or painted to prevent warping.

4 Install interior trim.