In the context of s 32(4) of the Sectional Titles Act 95 of 1986, an owner is 'adversely affected' by a special resolution modifying levy liability where the resolution increases that owner's proportional liability for levies. The expression 'adversely affected' must be given its ordinary, literal, grammatical meaning derived from authoritative dictionaries: unfavourable, disadvantageous, having a negative effect. An increase in levy liability is unfavourable both because the owner pays more and because the increased burden attaching to ownership diminishes the value and attractiveness of the property as an investment. Where an owner is so adversely affected, the written consent of that owner is mandatory under the first proviso to s 32(4), failing which the resolution is ultra vires and void. Courts cannot substitute notions of fairness for the clear language of the statute or render statutory provisos nugatory through interpretation.