SCTNE, I'm not sure that construction techs have anything to do with housing, I think they only relate to certain puzzles that require a builder. My understanding is that your builders will automatically start building huts when the population hits certain levels. For example, once you get to about 27 or 28 villagers, you will start building a new hut.

Because of this, I usually wait on the last construction level and go for science first to speed up research. My games seem to go faster that way.