The Role of Flexibility in Sustainable Prototype Unit Design: Riyadh Commercial Housing Developments, RCHD, Case Study

Abstract

Up to four decades ago Saudi traditional housing units were designed and built with local materials and expertise that corresponded with cultural values and fitted well with the local environment and climate. Local materials and technology were affordable to the majority of the population due mainly to the environmental sustainability of construction practices and building materials at the time. The boom of the mid-1970 witnessed the opening of local markets to a variety of building materials and technologies from all over the world. These materials and technologies were used to construct housing units in massive numbers without substantial research to test their compatibility with local culture and environment. One of the important factors contributing to the sustainability and life cycle cost of current housing units is design flexibility and the prediction and planning of unit future expansion, modifications and alterations. Modifications to the housing unit are normal phenomenon’s that accompany the household life cycle changes. For every stage of the families life has a different type of requirements dealing with play, study, storage and outdoor areas. Providing pre-designed alternatives for additions to existing housing units is beneficial in terms of the unit's life cycle cost and in maintaining healthy, diverse stable and sustainable communities. In the city of Riyadh, Saudi Arabia, the recent trend of building large number of units in commercial housing developments was perceived to decrease the flexibility of individual units. This study documented a representative sample of prototype units built recently in commercial housing developments in the city of Riyadh (RCHD). According to survey participants, RCHD units were moderate to highly flexible. The study identified three main categories of flexibility options with subcategories as significant predictors of overall flexibility namely functional flexibility (including ability to interchange and exchange spaces), structural flexibility (ability to extend the unit vertically or horizontally, and apply a system of standardized modularization), and cultural flexibility (ability to personalize the space). The last category of predictors was the only one that was negatively rated by RCHD survey participants. The study concludes with suggestions and recommendations to improve the flexibility options of RCHD units.