Just plate all of the roofs with gold. That'll keep the sun's rays from magnifying into a laser. Works for astronauts (did learn recently that it actually does help offer some protection from heat and (mostly) radiation in space, as the below link can help explain).
Actually, this may be a tenable solution. If sapphires are plentiful enough that no one would think it awkward to make cupcakes out of them (the episode "The Secret of my Excess"), it may not be a far stretch for gold to be an uncommon, or even somewhat common, metal instead of a rare metal.
Only real hitch would be how blinding direct sunlight reflected off of a metal surface would be (maybe they could put a glass tint on top of the foil as is done with tinted car windows).
Err.... That was more rambling than expected. In any case, funny comic. The faces in particular are very expressive and tell a lot of the story.