Construction Considerations for Adjacent Footing and Property Lines

An existing structure may be damaged during construction of new footing due to vibration, undermining or lowering of water table. The damage to the existing structure becomes greater with the increase in depth of new footing and with the decrease of distance of new footing to it. More severe condition arises when new footing is lower than existing footing.

The damage can be omitted by taking the precaution stated below:

a) The new footing if it is possible, should be placed at the same depth as the old ones and the sides of excavation adjacent to the existing structure should be suitably supported.

b) If the footings are placed at different levels, the slope of line joining the two footings should not be steeper than two horizontal to one vertical.