In most domestic buildings constructed after 1875 a horizontal damp proof course (DPC( formed of an impervious material is normally incorporated in the walls at ground level to prevent ground moisture rising up the walls as this could damage to the fabric of the building.
For a DPC to be completely effective the ground level outside should be at least 150mm below the level of the DPC. If it is not the ground level should be reduced and any paving relaid as necessary. Here is a newly laid patio which clearly bridges the DPC. This is a fundamental error. If it is not lowered it will without doubt lead to future dampness problems.