De Water v Muller [1912] ZATPD 113 (4 October 1912)

Work and labour -Building -Extras .-Implied contract-
Essentials.

Before a builder can recover the price of extras not
specially contracted for he must prove not only that
the extras were executed to the knowledge of the
building owner but also that the latter consented to
such extras being executed and knew, or must be
held to have known, that additional expense would
be incurred thereby.