Some Terms

HVAC - Heating, Ventilation, and Air Conditioning usually refers to the furnace and air conditioner but may also include exhaust fans, whole house fans, or air exchangers. Most of us just call the furnace guy.

GRADE - This term refers to the ground level around a building. The grade may be different during construction before topsoil is brought in (final grade). Above grade means the distance up from the ground. The best grade is one that slopes away from the building.

FROST LINE - The depth to which the ground freezes during cold weather. In the north it can be several feet; in the south it may not be a consideration. Building foundations must be built below the frost line. As the earth freezes it swells or heaves, and anything built above the frost line will heave with the earth.

- Stephen Corwin

-- Anonymous, May 30, 2001