Modelling an Optimisation Selection Method for Buildings Design Toward Environmental & Economic Objectives

Improving the performance of buildings based on their energy consumption is a challenging task. The main contributing factor to the amount of energy a building consumes is associated with maintaining the satisfaction of the building’s users, by controlling the conditions within a building’s envelope. Two main design factors control the overall buildings energy performance, the Heating Ventilation and Air Conditioning (HVAC) system design and building envelope design. There are several studies aimed at finding optimum solutions, evaluating these factors individually. The researches focused on the HVAC system design, has limited number of variables going into it, comparing different systems, operation set ups and fuels. As for the researches focusing on the buildings’ envelop design, a large number of envelope’s design variables can influence the building’s energy consumption, such as its shape, geometry, material composition, elevation, and location, lead to different energy consumption rates. This research systematically investigates how three main building envelop design variables (Orientation, Aspect ratio/compactness and Window to Wall ratio) impact the overall building’s energy performance, including the potential of integrating sustainable energy generation systems, in search for optimum buildings designs than can achieve an environmental and economic balance. The first component is specific to the analyses of buildings’ energy performance/consumption, based on the three building’s envelop design variables. The energy performance considers different building geometries (from a square to a rectangular aspect ratio that is of length twice the width). Then, orienting those different forms at different directions. Further, varying the external walls composition at different window to wall ratios. The results are used to calculate the net yearly energy consumption rates and understand the patterns of energy consumption influenced by those three variables. All simulations are specific to the climate condition of Kuwait’s geolocation, to develop an informed perspective of the climate influence on energy patterns. The results obtained have unique patterns that do not particularly agree with the general conclusions cited by other researches, specific to the relationship between buildings compactness and the energy consumption. With the growing concerns of climate change effects on the environment, it’s no longer enough to aim for passive mitigation solutions by reducing the energy consumption. The goal is to push for active ways to generate energy using sustainable resources, when possible, in the most economically feasible way. Hence, the second component of this research, focused on the opportunities to utilise the envelope for energy generation. By integrating sustainable energy generation systems within the buildings’ façade, the dependency on the power from the grid, that is 10 mostly generated using fossil fuels, can be reduced. The climate characteristics of the Gulf Cooperation Council (GCC) countries impose specific challenges on buildings’ energy performance as well as the efficiency of sustainable energy generation systems. Specific challenges such as the effect of dust on the most productive sustainable source for energy generation, solar photovoltaic systems, must be considered. Accordingly, a prediction model is created to quantify the regional effect of dust on the productivity of PV systems. Then, given the specific building variables used in the buildings’ energy consumption calculations, the energy generation potentials are calculated. The last component of this research aims to optimise the objectives of lower energy consumption rates, higher energy generation potentials (Lower emissions), and lower investment costs. A model is created to find optimum solutions that can balance those contradicting objectives. The results are obtained to provide guidance to the designers toward environmental and economic decisions, through a set of different possible design combinations