Formalities can be imposed by statute or by the parties itself. No formalities are required by statute for the
conclusion of a contract for construction works in South Africa, but the communication of some form of offer and an acceptance in reply, should be regarded as the minimum documentation as proof, that the parties have reduced their agreement in writing and what the contents and basis of that agreement is.

Having regard for the fact that a construction contract must include some form of specification or drawing
that must be met, the method of inspection and testing to ensure that the approval criterion is clear, clarity
on the period for performance and the method of quantifying interim payments, it is therefore almost
inevitable not to reduce an agreement for the execution of construction works to writing, to ensure that these
salient rights and obligations are clear. The presumption is that parties who resort to writing of their own
accord do so for evidential reasons rather than to impose formalities. Irrespective of whether parties resort
to writing for the creation of a contract or merely for purposes of proof, the agreement can be varied by
informal of formal agreement.

However, where, by means of a so-called non-variation clause, parties have prescribed writing as a formal
prerequisite for variation of the contract, the position may be different. The non-variation clause is part of
the contract and if it is phrased widely enough to entrench itself, no part of the contract, including the nonvariation clause itself, may be varied in any other way other than in writing. Non-variation clauses are
usually strictly enforced by the courts as a policy decision based on a preference for commercial certainty
and avoidance of litigation.

Does your contract or subcontract contain a non-variation clause? If so, then usually any variation to the terms and conditions of the contract or subcontract may only take place by reducing the varied terms to writing and to be signed by the contracting Parties. This will then constitute a clear “meeting of the minds”. The flipside then also applies. In a contract or subcontract with a non-variation clause, a party cannot rely on additional payment, compensation or rights for acting on a so-called agreement that was never reduced to writing and signed by the Parties.