There are also tricks in doing the modeling and actual UV mapping that can be very helpful. Looking at Ockham's house, you would definitely want to layer those walls on top of each other so they can take up as much space on the texture as possible rather than just leave them in the initial box mapping projection. Line them up carefully too. Nothing worse than mismatches in the mortar lines in a UV mapping job.

For Bagginsbill's building, you might take those brick columns and break them up by mapping and duplicating rather than sizing a simple cube the entire height of the building. Don't model to completion and then map. Think mapping as you are modeling.