Design four icons to match existing icon set

Design details: We have an existing set of map marker icons which feature different types of dwelling - we need four new icons which represent typical english homes - an average two story detached house, a flat, end-of-terrace home, semi-detached home.

Our current icon set is available as a psd file, with vector smart layers that open in illustrator. The final deliverable is an updated psd of the complete set with vector smart layers and each icon exported as a png (84 x 106px) for standard displays and a second for retina
Ideas for the visual style: Match existing icon set
Extra notes: