Walls are classified as either bearing or non-bearing. Bearing walls help carry the weight of the house, providing support to floors above and the roof. They should not be removed without a properly engineered method of support--typically a system of beams--during and after removal.

Non-bearing walls help shape a house's interior by defining rooms and serving as conduits for plumbing and electrical systems. They may be removed without compromising the house's stability, though mechanical systems within the walls such as wiring and plumbing must be capped off or re-routed.

All exterior walls are bearing and many interior walls may also be bearing, especially in multi-level homes. Normally, at least one main interior wall, situated over a girder or interior foundation wall, is also bearing. If you are unsure whether or not an interior wall is a bearing wall or how to provide the necessary support during and after removal, consult a local building professional before doing any demolition work.