Energy Sensitive Designs: Evaluation and a Proposed Model for Residential Buildings in Warm Humid Climate

Abstract

The warm humid climate of Osogbo is characterised by its high humidity, relatively high temperature, and four distinct major seasons. Hence, this paper is aimed at assessing the climatic responsiveness of the five major residential building design types in Osogbo with a view to develop an energy sensitive design framework for a warm humid climate. This involves synergizing the comparative advantage discovered in each design type predicated on the Mahoney Tables assessment criteria. Data were obtained through measurement and assessment of the design characteristics of 209 residential buildings design types in Osogbo. Four political wards with the predominance of each of the five building design types (namely; traditional houses, rooming-apartments, apartments, bungalows and duplexes) were purposively selected. Buildings were assessed on layout (orientation), spacing between buildings, air movement (inlet/outlet), size of openings (fenestration), wall materials (thermal transmittance) and roof characteristics (thermal reflectance and transmittance). Findings revealed that the bungalow designs had better orientation compared with the other buildings surveyed. The duplexes had better spacing; the rooming-apartment designs had adequate air movement. Likewise approximately 70.0% of the surveyed residential buildings had adequate fenestration. The result also revealed that approximately 90.0% had their external walls constructed with hollow blocks of low thermal transmittance and lastly 15.3% of the total residential buildings had roof of high thermal reflectance and low transmittance. Out of this percentage, the duplex building designs accounted for the majority. Finally, an energy sensitive design framework was evolved from the comparative assessment of the five residential building design types analysed.