An optimal model for housing projects according to the relative importance of affordability and sustainability criteria and their implementation impact on initial cost

It is possible to categorize the housing problems in Saudi Arabia based on two important factors, one quantitative and the other qualitative. The quantitative aspect is indicated by the inability to meet the increasing demand for housing, and the qualitative aspect is manifested in the fact that the current housing model does not take into consideration sustainability criteria, the quality of construction, and the life span of the house. The Kingdom's 2030 vision to raise housing ownership from 47 % to 52 % makes it necessary to find models for applying affordability and sustainability criteria. This paper aims to determine an optimal model based on the design, construction, operation and deconstruction criteria of both affordability and sustainability for residential neighborhoods and detached houses (villas). It outlines a new comprehensive approach to determine the priority criteria ranking of affordability and sustainability to be applied to low- and middle-income housing projects. The approach was developed by evaluating five models of criteria according to their relative importance and impact on the initial cost. The model selected was developed according to the local needs of Saudi Arabia, thus minimizing their environmental impact. In addition to being cost-effective, where the initial cost is reduced by 16 %–45 % after applying affordability criteria, the added cost of applying the mandatory sustainability criteria does not exceed 3.91 %. In conclusion, the study showed that this model is the ideal one for affordable and sustainable housing development for middle- and low-income households.