The absence of approved building plans for buildings on a property constitutes, in our law, a latent defect in property. Avoetstoots clause in a sale agreement will address this issue and protect an innocent seller from comebacks from the purchaser.  

For example, seller X, unawares that there were no plans for certain of the buildings on his property, will not be liable to buyer Y to make good his (Y’s)additional expenses incurred when his planned renovation to his new home involves costs of subsequent approval of existing renovations.

A question that often arises in this regard is the issue of wendy houses. Is approval required? The Building Standards and Building Regulations Act requires that property owners obtain municipal approval generally in respect of all buildings, additions and renovations, no matter how small. 

However, in certain instances relating to smaller changes, full plan approval is not required, but the municipality must still be approached for written consent that formal; building plan approval is not required. "Minor building works" include, amongst others:
iv.           "tool shed not exceeding 10 m2 in area;
v.            child's playhouse not exceeding 5 m2 in area;
vi.           cycle shed not exceeding 5 m2 in area;
vii.          greenhouse not exceeding 15 m2 in area;
x.            any pergola;
xi.           private swimming-pool", etc.

These building works do not constitute a general exemption: the municipality must still be approached for written authority that plan approval is not required.