Building boundary definition
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a boundary as:
'The boundary of the land that belongs to a building, or, where the land abuts a road, railway, canal or river, the centre line of that road, railway, canal or river.'
A relevant boundary is 'the boundary or notional boundary that one side of the building faces and/or coincides with, and that is parallel or at an angle of a maximum of 80 degrees to that side of the building.'
A notional boundary is: 'a boundary presumed to exist between two buildings on the same site.'
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