There can be a huge number of different reasons for cracks in the home.
Settlement cracks in concrete walls.
Settlement cracks in outer cavity wall of property.
Vertical cracks in walls built with concrete blocks or sand lime bricks.
A settlement crack may also appear as a random crack above areas where the soil of the subgrade was uneven after the concrete was poured.
Concrete walls containing horizontal cracks are serious issues.
Cracks in external and internal walls of load bearing structures.
Cracks generally occur at weak sections i e at midpoints or at regular intervals in long stretches.
If a vertical crack widens at the top or bottom the wall is either settling or gradually heaving which may present serious issues.
The cracks may be straight or toothed.
How to determine if the cracks in walls are serious.
Horizontal cracks in concrete walls however indicate poor wall designs or pressure buildup behind the wall.
Settlement cracks are usually more extensive at the top of the crack than the bottom as the foundation bends over a single point allowing differential settlement.
Stair step cracks may also signify heaving.