Living in NJ it gets a little cold outside and we are working on swim lessons with our 19 month old son in the hot tub set at 94 degrees. Last winter the wife and I enjoyed it all year round no matter what the temperature was and even when it was snowing. This year with our son I want to build a temporary enclosure for the winter that can keep up a little warmer when we are in it working with him. Has anyone built such a beast? Looking for ideas. Otherwise I will most likely use 2x4 construction and T-111 the exterior with coffin lock latches to connect the panels together and make a single direction sloped roof with corrugated clear roof panels for some daylight. Thoughts?