Think about the features this house would have, and add those.
Required: Entrance(s), such as doors or gates, roofing material (shingles, tiles, metal, thatch, etc)
Very Likely: Windows (including basement windows, etc), wall material or siding
Likely: Rain gutters, visible window/door structure (sills, lintels, thresholds), visible wall structure (ends/ties of timbers/beams supporting storeys, stronger/bigger bottom walls, especially those around a basement) stairs leading up to doors, railing around longe/steeper stairs, architectural decoration (visual separation between storeys, moulding around the doors and windows)
Possible: Planters, additional decoration and items (water spouts, rain barrels), signs of age (cracks, skew resulting from a slipping foundation, missing chunks of decoration,
The function of the building will influence the elements it has. For example, a storage house will have larger and numerous doors, including possible doors on the upper storeys, while a residential house will likely only have 1-2 small doors.
Location and culture influences the architectural style and materials used. Your background buildings are a great opportunity to communicate a lot about your setting to the viewer/player, don't miss out on it! Don't be afraid to seek reference of similar real-world locations to give you ideas for how things should look.
...and this is all before getting into all the things the residents bring in! Toys, work benches, transportation, plants, curtains, how clean it is, the possibilities are practically endless. You could get many uses out of the same base house just by changing the details of the inhabitants.
