Thesis (MBA)--Stellenbosch University, 2011. / The aim of this research study is to determine the cost gradient for Green Star SA-rated office buildings in the Western Cape province of South Africa. Very little work has been done on this subject, due to the fact that the „green‟ building movement is still in its infancy in South Africa. The Green Building Council of South Africa (GBCSA) has developed a Green Star SA building rating mechanism based on the Australian green star-rating system. This rating system provides the building environment with an objective tool to evaluate how green a building actually is. This report includes a review of international literature, supplemented by a case study of two designed „green‟ buildings. The key objective was to determine if there is a cost premium to a Green Star-rated office building in the Western Cape. The case study subjects were two office buildings planned for an office development at Paardevlei, Somerset West in the Western Cape province of South Africa. The findings of this case study have confirmed first indications that South Africa, and specifically the Western Cape, should be no different to the rest of the world and specifically the United States and Australia when it comes to the first costs of constructing „green‟ buildings. The case study showed that there should be no cost premium for a „green‟ building that conforms to the minimum standard of 4 Star Green Star SA Office Version 1 and that a one to three per cent premium could be expected for a 5 Star Green Star SA Office Version 1 rating. It was found that the best way to calculate if a premium was paid for a „green‟ building is to compare the cost per area of the final „green‟ product with the cost per area of the original budget. Adding costs while adding „green‟ attributes proved to be an effective and convenient way of arriving at a theoretical premium for a progressively „greener‟ building and thus calculating the cost gradient for Green Star SA-rated office buildings. The conclusion is that „green‟ attributes must be incorporated into the design at the earliest possible stage and then managed in order to keep within the original budget with a clear goal of which categories are to be targeted and what rating would like to be achieved, in order to achieve a „green‟ building at no additional cost.