The Ontario Building Code | Structural Separation
4.1.8.14. Structural Separation
(1) Adjacent structures shall either be separated by the square root of the sum of the squares of their individual deflections calculated in Sentence 4.1.8.13.(2), or shall be connected to each other.
(2) The method of connection required in Sentence (1) shall take into account the mass, stiffness, strength, ductility and anticipated motion of the connected buildings and the character of the connection.
(3) Rigidly connected buildings shall be assumed to have the lowest RdRo value of the buildings connected.
(4) Buildings with non-rigid or energy-dissipating connections require special studies.
In Plain Language
Adjacent structures must either be separated by a distance calculated from the combined deflections of both structures, or otherwise designed so they won't pound against each other and cause damage during seismic movement.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.