So-called ‘net contribution’ clauses are often contentiously debated at the drafting stage when framing professional and building contracts for a development. An example of one being enforced in practice appears in a recent Northern Irish High Court decision apportioning blame for defects between an architect and a building contractor

The case of Radius Housing Association Ltd v JNP Architects and others[2018] NIQB 57, 4thJuly 2018, is kind of a classic case of construction ‘whodunnit’ where defects have arisen but there is dispute as to whether it arose from the professional design or the building contractor’s workmanship. The case of course was largely decided on its facts, but it is significant that the court upheld the net contribution clause in the architect’s appointment as being effective, with the result that it is now open to the architect to bring appropriate evidence of contractor contribution to the defects.