Green Building Strategies and Material Selection for Hot-Dry Climatic Conditions of North-Western Nigeria: A Delphi Approach

Generally, buildings provide society with countless benefits, however, they also have major negative impacts on the environment. Hence, Green Buildings (GB) have been proposed to solve this issue as they adopt fewer harmful materials and enable the use of local materials to adapt to climate conditions while consuming natural renewable resources with an emphasis on environmental sustainability. However, there is the dearth of researches that focus on the types of GB materials that could be adopted in the Nigerian construction industry. Hence, this research aim at finding out available materials and strategies that can be adopted towards attaining a GB status within the hot-dry areas in the north-western part of Nigeria. A total of 25 experts were drawn across three professional bodies including the Nigerian Institution of Estate Surveyors and Valuers (NIESV), Nigerian Institute of Architects (NIA) and Nigerian Institute of Building (NIOB). Using a 5 point Likert scale ranking, the study explores 33 materials cum strategies for hot-dry climatic conditions. Delphi method was adopted to find out available materials and strategies that can be adopted towards attaining a GB status within the study area. Consensus was reached at the 4th round of the survey where 19 number materials were agreed upon as easily available and suitable for the region. These include straw bales using cane straw, wheat stalks, maize husks, cottonseed husks, tamarin hull particles, adobe bricks, ash waste bricks, autoclaved aerated concrete, onion peels, groundnut shells, sunflower stalk, cork and fired clay for walling and insulation. Jalis and wind-catchers for ventilation; grass Crete and timber Crete for outdoor flooring and living roof and clay roof tiles as roofing materials. Hence, this study recommends the adoption of these materials to reduce heat-related impacts on the environment caused by buildings.