If you want to turn your existing garage into a granny flat then the following need to be taken into consideration. Basically you will probably need to apply for consent for a second dwelling on your property.  Some areas like the Johannesburg area already allow a second dwelling or cottage to be built on the property. You will also need to check your title deeds and zoning to see if there is a restriction on having a second dwelling.  There are some factors that will allow separate living where there are inter leading doors etc.  If you are installing a second kitchen then the granny flat will be viewed as a second dwelling.  Some people try and circumnavigate the Consent process by putting in plans for a Staff Quarters.  Many Councils have tightened up the criteria for a Staff Quarters and would not approve the plans until they had Town Planning Approval for a second dwelling.  However if you do decide to go this route, bear in mind that you will be liable to pay the fines that the Municipality will impose for illegal building.