Sure, you can build your own surround. As a matter of fact, a lot of our customers do exactly that. If you go to our website and click on “expert advice”, and then “installation guide” you will be able to download a 12 page PDF document with our CAD drawings and the exact size with electrical requirements.
Basically, you can build a surround out of wood or any other material you like. Just make your opening is 28” inches wide by 22” inches tall and frame over the top 10” inches (of the 32” inches total height). However, don’t build anything custom until you physically have our insert in your possession so there’s no surprises.