Ask a pro: Build your own windows

If you can build a reasonable piece of furniture, you can build your own windows. The easiest window type to build is a casement, because it’s like a door and is relatively easy to fit and seal. To make the sash and frame, choose a very durable, exterior-grade wood; Douglas fir or Alaskan yellow cedar are good choices.

To mill the sash profiles, you’ll need a set of sash-making router bits and a router table. I used a set from Dimar’s Nova line that did a great job of profiling the inside edges (the indoor side) and coping the joints for a tight fit. In many ways, making a window sash is like making a frame-and-panel door, except that rather than having a panel groove in the centre, you need a rabbet on the outside face of the sash for the glass to fit into. The other difference is that full tenons, rather than stub tenons, are necessary for strength.

For energy-efficient double glazing, you’ll need to get a glass shop to make you some sealed, double-pane units. There are a few options you can order: the thickness of the glass spacer bars and the material they’re made from; whether to have the space between the glass panes filled with argon gas; and even special, energy-efficient coatings on the glass.

To secure the units in place, you’ll need to use a special, non-reactive silicone caulking that won’t harm the sealant in the double-glazed glass units. I used Tremsil 600 on my windows. The caulking glues the glass to your sash, but you’ll also need to hold the glass in place mechanically with wooden glazing strips fastened with brads.