Buildings are one of the largest energy consumers in the world, and have great energy saving potential. Thermal systems and lighting systems take most of the energy in a building. Comparing with the optimization solutions developed for a thermal system, the research of improving the lighting system is insufficient. This study aims to improve the lighting environment and reduce the energy by optimizing the building design, which has the largest potential for cutting energy economically compared with the other stages in the life cycle of a building. Although many approaches have been developed for building design optimization, there is still one big problem obstructing their successful practices, in that the designers who take the responsibility of making building designs are not experts in building physics, thus they are not capable of calculating the most appropriate parameters and operating the professional software to optimize their designs. Therefore, this study proposes a user-friendly method for designers to improve building designs. Firstly, Building Information Modeling (BIM) and particle swarm optimization algorithm are applied to build an intelligent optimal design search system. The optimized design from this system can largely use daylighting for internal illumination and save energy. Secondly, different types of lighting control systems are compared and the one which can save maximal energy is added to the selected optimal design. A case study demonstrates that optimized designs generated by the proposed design method can save large amounts of life cycle energy and costs, and is effective and efficient.

Due to the highly competitive commercial environment in the market in Yemen at present, the construction industry in Yemen, like other industries, is under pressure to reduce product development time and overall project costs, improve product quality, and satisfy customers. To keep pace with the competitive environment of the market in Yemen, most enterprises tend to adopt the best and new technologies, new management concepts and philosophies such as Total Quality Management (TQM) and concurrent engineering (CE) to achieve improvements in the process of product development. In this paper, the problem of fragmentation brought by the serial engineering in construction in Yemen is discussed firstly. Then, the integration process and CE adoption by the construction industry in Yemen are explained for enabling construction agencies in Yemen to improve the development process of their projects and to solve the current fragmentation problems such as the lack of communication, adversarial culture and the lack of customer focus, which allows the construction process to improve and become more effective and efficient.