Development of a building energy efficiency assessment tool for office buildings in Ghana
Abstract
The built environment is responsible for some of the most serious global and local
environmental changes. This is exacerbated by increasing energy demands and decreasing
resource availability. Building energy remains a critical criterion amongst both developed and
developing nations and its availability cannot be overemphasized. In Ghana, more focus has
been placed on the supply side, with measures taken to overcome the current supply deficit. In
spite of the importance of improving the supply side, the demand side cannot also be
overlooked. Interestingly, studies show that electricity demand is fast increasing, hence a need
to relook at the strategy to curb this growing problem. In this thesis, the focus has been placed
on demand side management. The thesis sought to answer one key question: how can one
determine whether a building is energy efficient or not? A basic question, yet a critical starting
point for energy efficiency studies in Ghana. Consequently, the overarching aim of the study
was the development of a building energy assessment tool to be used in determining the energy
efficiency of office buildings in Ghana. To achieve this aim, four main research objectives were
formulated and a mixed methodology approach adopted. A combination of four different
methods were used in this research: review of pertinent literature, Delphi survey, Delphic
Hierarchy Process (DHP) and Simulation study. The first objective sought to examine methods
used in building energy performance assessment towards the development of a conceptual
framework. From the review of literature a conceptual framework was developed. The second
objective sought to identify applicable criteria to form the dimensions of the building energy
assessment method. A Delphi survey was conducted in two successive rounds following the
literature review. Expert opinion from fields of academia, industry and government were
assessed and consensus established showed that the international assessment methods are not
fully applicable to the Ghanaian built environment. Five main bloc ks were established: the
energy performance indices; calculation of energy performance; assessment of energy
performance; setting of energy efficiency limit a nd energy performance labelling. Following
this, the Delphic hierarchy process was used in achieving the third objective. This involved,
the development of a customised weighting system for the Ghanaian environment. The
resultant weighting system had build ing design having the highest weight followed by energy
efficiency of building facilities. Use of renewable energy had the lowest weight. The findings
reflect the current development of building energy data studies. It was noted that despite the
huge role that renewable energy can play in reducing energy efficiency, current economic
issues present an impediment to its investment and subsequent development. To achieve
iv
objective four, a simulation study was undertaken to test and validate the developed weight ing
systems and further propose a grading system. Building energy data studies provided the
required framework to properly develop the tool. It is important to state that the outstanding
contribution of the study lies in the final tool developed for determining the energy efficiency
of office buildings at the design stage. The development of a building energy assessment tool
amongst many would contribute to energy security and economic stability. Such a tool can be
adopted by energy planners, policy developers, building scientists, facility managers and
designers in the planning, design and implementation of energy efficient building. Almost all
well-known building assessment methods are updated and revised either annually or
biannually. Therefore, it is recommended that the tool be subject to regular review which will
inform required development and updating. Further developments should incor porate the
developments of guidelines needed whilst using the tool. It is recommended that future studies
explore building optimisation studies. This is necessitated by the dearth of study in this field in
Ghana and a need for more direction to undergird the full utilisation of the developed tool. Also
the interplay between cost and building energy efficiency is worthy of investigation in further
research.
Description
A thesis submitted to the Department of Building Technology, College of Art and Built Environment in partial fulfillment of the requirements for the degree of Doctor of Philosophy,