DIY portable screen room for bugs? Or buy one?

In my experience - both in North America and East Africa - screen enclosures are far from perfect. It's difficult to get a perfect seal everywhere and mosquitoes invariably find their way in. We have even found it necessary to spray around the inside of the enclosure with a can of pyrethrin spray after setting up to kill the ones trapped inside. We have foregone the expense, storage space and trouble of enclosures in favor of good insect repellent.

Rob