Even if you are building cash and the bank won't require a certificate, your Conveyancing Attorney is obliged by law to make sure that the house is enroled.

Act 95, Section 18: Obligations of mortgagees, conveyancers and provincial housing development boards

(2) Any conveyancer attending to the registration of a mortgage bond in favour of an institution contemplated in subsection ( 1 ) shall ensure that the home builder is registered in terms of this Act, has enrolled the home with the Council and has paid the prescribed fees in respect of that enrolment.