Department of Architecture and Built Environment Energy Efficient Strategies for the Building Envelope of Residential Tall Buildings in Saudi Arabia Noura Abdulrahman Ghabra BSc, MArch Thesis submitted to the University of Nottingham for the degree of Doctor of Philosophy November 2017 ABSTRACT The energy demand in the Gulf countries in general and in Saudi Arabia in particular has been increasing sharply in the last decades as a result of the diversification plans that aim to reduce reliance on oil-based income. Tall building construction, associated with many environmental and ecological challenges, played an essential role in these plans, as a mean to attract new economies based on global placemaking and international tourism. The significant use of air conditioning to cool indoor spaces, particularly in residential buildings, accounts for more than half of all energy consumption in the country, and despite governmental efforts, the scattered conservation efforts have been largely ineffective due to factors such as lack of awareness and information, in addition to the limitation of the local energy efficiency building regulations. This research aimed to find and prioritise building envelope design solutions that can reduce high energy consumption and cooling loads while maintaining indoor environment for residential tall buildings in Saudi Arabia. In order to achieve that, a hypothesis of integrating engineering and design parameters of the building envelope as a design strategy for tall buildings envelope were proposed, and to test it, a mixed method approach was followed including literature review, data collection, dynamic building simulations and parametric analysis. The main findings emphasised how combining both engineering and design parameters of the building envelope can be an effective way to achieve energy efficiency in residential tall buildings in the hot climate of Jeddah. Especially in relation to solar heat gains, the highest contributor to cooling loads in this building type. The findings highlighted that while the thermal properties of the wall type can reduce up to 10% of the cooling loads, applying external shading devices can achieve a reduction of up to 30% in solar gains. Moreover, effective consideration of building orientation can significantly reduce cooling loads by 25% and solar gains by 60% for the perimeter zones. Based on this, a set of guidelines that incorporate a comparative tool were introduced to help designers to determine the thermal performance and energy use of a typical residential tall building in the early stages of the building’s design. Which also aim to enhance the effectiveness of the local building codes and energy efficiency regulations in relation to this building type. i ACKNOWLEDGEMENTS In the name of Allah, the Most Gracious, the Most Merciful To all those people who I greatly doubt will ever read my PhD - except my supervisors and proof-readers- nevertheless, as Rowan Moore (2012) said, they have “provided in different ways the inspiration, information, education, help, love and/or DNA without which this book would have been impossible”: First, my Parents, Abdulrahman and Azzah: for being there since I opened my eyes into this world, leading and guiding, pushing forward and sometime pulling me back to sanity, standing beside me in times of need and distress, and helping unconditionally with life’s ups and downs. Ahmad: who taught me how to be myself, and showed me how to independently work my way throw life. My Brothers, Hussam, Amer and Yasser: for the endless laughs, shared cries and crazy hugs My Supervisors: Lucelia, who truly inspired my whole existence as a researcher, a seeker, a mother, and a woman, and whose constructive criticism and gentle guidance has led me through this unforeseen journey. I’m eternally thankful for you Lu. Special thanks to Phil, for his light and positive personality, his ever so helping attitude, who is always there to offer knowledge and support, and push me when I’m just lost and fanatic. Brian, the role model who taught me the true meaning of searching and researching, questioning, looking for answers, just to question them again. His wise eyes and words changed me more dramatically than he would ever imagine. Thank you again for everything. David, for always believing in me, and opening a lot of doors and introducing me to the many people who were a vital part of this work. My Friends in SRB: Lorna and Renata, Ikrima, Yanti and Mengwie, who helped me tremendously with my research whenever I’m stuck, and who assured me I’m totally normal when I thought I’m on the verge of insanity. My Friends in Nottingham and UK: Lina and Samar, the two most beautiful inside out. Who always offered endless mental, emotional, and motherhood support, while sharing the unexpected PhD journey. And Douha, most generous soul, never ceases to put a smile on my face and faith in my heart. My amazing fellow doctor and friend. My virtual and reality friends: Nisreen, Nasab, Riam, Arwa, Who supported me overseas, all the way from Saudi and all over the world, your calls and video calls made my days and nights. All the friends and staff I met in Hallward and Boots libraries, and Nero cafes around Notts, who made this journey more fun and bearable Thanks a lot Alex, Fayiz, and Mohammad, for all the proofreading, and endless support when I doubted myself the most. And finally, I dedicate this work to the best gift I have never dreamt of, Dana, my daughter, who glued it all together. ii PUBLICATIONS Ghabra, N., Rodrigues, L., Oldfield, P., 2017. Improving Energy Performance in Gulf-Region Residential High-Rises. CTBUH Journal 2017 Issue III Ghabra, N., Rodrigues, L., Oldfield, P., 2015. Energy Efficiency In Residential Tall Buildings Of The Gulf Region: Trends And Solutions. In: Passive & Low Energy Architecture (PLEA) 2015 Conference: Architecture in (R)Evolution. 9-11 September, Bologna, Italy. Ghabra, N., Oldfield, P., Rodrigues, L., 2015. Investigating the Role of Façade Design in Improving Energy Efficiency for Residential Tall Buildings in Saudi Arabia. In: The 14th International Conference on Sustainable Energy Technologies: Sustainable Energy for a Resilient Future. 25-27 August, Nottingham, UK In press: Ghabra, N., Rodrigues, L., Oldfield, P., 2017. The Impact of the Building Envelope on the Energy Efficiency of Residential Tall Buildings in Saudi Arabia. International Journal of Low- Carbon Technologies iii TABLE OF CONTENTS ABSTRACT ............................................................................................................................................ i ACKNOWLEDGEMENTS .................................................................................................................. ii PUBLICATIONS ................................................................................................................................. iii TABLE OF CONTENTS ..................................................................................................................... iv LIST OF FIGURES ........................................................................................................................... viii LIST OF TABLES ............................................................................................................................. xiv LIST OF EQUATIONS ..................................................................................................................... xvi LIST OF ACRONYMS ..................................................................................................................... xvii INTRODUCTION ................................................................................................................................. 2 Chapter 1 ENERGY AND RESIDENTIAL TALL BUILDINGS IN THE GULF REGION ...... 12 1.1 Gulf Region: The Context .............................................................................................................13 1.1.1 The Economic and Energy Context ....................................................................................................15 1.1.2 The Climatic Conditions in the Gulf Region ....................................................................................23 1.2 Housing and Tall Buildings in the Gulf Region ....................................................................36 1.2.1 Housing in Saudi Arabia .....................................................................................................................37 1.2.2 Housing Types in Jeddah ....................................................................................................................39 1.2.3 Tall buildings in the Gulf Region: Historical Background ......................................................... 42 1.2.4 Functions, Typology and the Culture of Glass ................................................................................47 1.3 Conclusion ............................................................................................................................................49 Chapter 2 TALL BUILDING ENVELOPE DESIGN, FUNCTIONS AND PERFORMANCE . 52 2.1 The Functions of the Building Envelope ....................................................................................53 2.1.1 Thermal and Light Transmittance ......................................................................................................53 2.1.2 Solar Gain ......................................................................................................................................................55