1. Cracked foundation walls and masonry stair-stepping.
2. Footing conditions. Although the existing footings for house could be suitable for the existing footings. The addition of an extra floor load could permanently damage the existing footings. Additional footings may be required adjacent to the existing. Look for piers that are leaning, cracking, rusting or settling, deteriorated mortar.
3. Basement wall retaining: Beware of basement walls that are cracked and bowing. This could be a signal that the wall is not vertically reinforced. Look for horizontal cracks at wall mid-height
4. Site retaining wall. Concrete and masonry retaining walls are designed to last over 50 years, but timber retaining walls generally have a lifespan of less than 25 years. All of them are subject to environmental damage from moisture exposure to slope failure. Look for wood rotting, rust stains and surface cracking from exposed rebar, evidence of sliding from addition of surcharge, improper footing depth and inadequate wall drainage.