This work addresses the use of an electromagnetic wave sensor to determine moisture content within building fabrics. Building materials that require a special mixing ratio such as concrete, mortar and membrane layers will be subject to significant effects when exposed to unpredictable weather changes owing to the excess of the acceptable moisture content. The acceptable moisture content level varies with various building fabrics and exceeding this level will affect the overall performance of building constructions. The project proposes using a novel electromagnetic (EM) sensor to monitor, in a non-destructive manner, the signal reflected from building structures in real time to determine exceeded moisture content level. This project involves the design and construction of an EM sensor operating at two frequency ranges: 2GHz to 6GHz and 6GHz to 12GHz at a power of 0dBm. This research is a new approach for monitoring moisture in buildings which has not been investigated before. The simulation software High Frequency Structure Simulator (HFSS) was used to model the microwave sensor. The pyramidal horn antenna was chosen as the preferred antenna for this work owing to higher gain, directivity and overall performance. Different building materials and structures have been made in a laboratory environment to determine the levels of moisture content, as well as to determine the modes of building fabrics failures owing to membrane failure, a pipe burst and ground source. Finally, a graphical user interface was developed and used to control the sensor parameters as well as frequency sweep, to capture the data from the sensor. Based on the findings of this project, the EM wave sensor could be used to determine the moisture content of building fabrics in a non-destructive manner.

Buildings represent more than 40% of final global energy consumption, among which 50%-60% of energy consumption is attributed to Heating, Ventilation and Air Conditioning (HVAC) systems. The application of phase change material emulsions (PCMEs) in air conditioning systems is considered to be a potential way of saving energy because with their relatively higher energy storage capacity, they are able to reduce flow rate whilst delivering the same amount of cooling energy. PCMEs can also simultaneously act as cold energy storage to shift peak-load to off-peak time and improve coefficient of performance of systems. However, one of the main barriers affecting the application of PCME is the difficulty in maintaining stability in the emulsions without experiencing any temperature stratification during phase change process. To this end, an innovative energy efficient phase change emulsion has been developed and evaluated. The emulsion (PCE-10) which consists of an organic PCM (RT10) and water has a phase change temperature range of 4-12°C with heat capacity of twice as much as that of water thus making it a good candidate for cooling applications. Particular attention was also paid to the selection of the surfactant blends of Tween60 and Brij52 since they are capable of minimizing the effect of sub-cooling as well as ensuring stability of the emulsion. For the purpose of testing the performance of developed PCE-10 in fin-and-tube heat exchangers, series of theoretical and experimental studies have been carried out to understand the rheological behaviour and heat transfer characteristics of the developed PCE-10 in a fin-and-tube heat exchanger. Both experimental and theoretical results were fairly close and showed that the PCE-10 did enhance the overall heat transfer rate of the heat exchanger. In order to evaluate the potential of the integrated system, whole building energy simulation was carried out with a building simulation code TRNSYS. It was found out that the required volumetric flow rate of PCE-10 was 50% less than that of water which is equivalent to 7% reduction in total energy consumption when providing the same amount of cooling power. Despite its potential in cooling systems, the viscosity of the developed sample was found to be much higher than water which could contribute to high pressure drop in a pumping system. Its thermal conductivity was also found to be about 30% lower than the value for water which could influence heat transfer process. There is therefore the need to enhance these thermophysical properties in any future investigations.

Decision making during the adoption of Building Information Modelling (BIM) in current AEC projects is believed as a key element to improve both BIM performance and project outcome. In order to provide the most informed decision and strategic plan, two vital elements are required: a comprehensive set of decision making criteria and a reasonable priority system. The literature analysis has revealed that existing assessment frameworks have limitations concerning these two elements. Therefore, this research has been designed to develop a more effective BIM evaluation Framework (BeF), to assist new BIM users and also provide a more effective implementation approach for BIM. In order to accomplish this objective, research steps of theoretical and empirical nature have been adopted: (a) a multi-dimensional BIM implementation Framework (BiF) was proposed based on the literature review; (b) use of a case study to test the proposed BiF on a real-life project; (c) a questionnaire approach to test the comprehensiveness of the proposed BiF on an industry level; (d) applying the Delphi method to further refine the proposed criteria in a specific context; (e) using the Analytical Hierarchy Process (AHP) to develop a BeF and providing priority shifting for a more preferable strategic goal in Arup ShenZhen office (ASZ); (f) developing a validation system to prove the efficacy of the proposed BeF. The adoption priority and approach of BIM could be influenced by policies, culture, business structure, legislation etc. As a result, a specific context, China has been selected for this work. The research result could assist decision making in BIM management in the ASZ for a higher BIM performance. The framework by the Delphi method is suitable for the selected context: China. The proposed Delphi and AHP methodological framework can be replicated to assist decision making of BIM management in any AEC organisation.

Crack detection at an early stage can prevent catastrophic structural failures. In this thesis, the inverse problem of crack detection in frames is studied. The direct problem of calculating the natural frequencies of beams and frames with multiple cracks is first tackled. A new method for natural frequency calculation is devised. The cracks are modelled as rotational springs. 4 × 4 dynamic stiffness matrices for beams are evaluated in a recursive manner, according to the number of cracks, by applying partial Gaussian eliminations. The resulting transcendental eigenvalue problem is solved using the Wittrick–Williams algorithm to extract the natural frequencies. Additional sign counts resulting from the partial Gaussian eliminations must be accounted for when applying the algorithm. The dynamic stiffness matrix of a frame with multiply cracked members is then assembled. The natural frequency calculation method forms a basis for detecting a single crack in a frame using only natural frequency measurements. Each frame member is discretised into a number of points. Selected natural frequencies are calculated accurately in the uncracked case and when the crack is placed individually at each discretisation point. The variation between the uncracked and cracked frequencies is normalised giving a number of curves corresponding to the selected frequencies. The normalisation is then applied on the measured frequencies. For noise free measurements, point crack locations are obtained. Applying the principles of interval arithmetic, noisy measurements give crack location ranges. Empirical probability distributions are used to graphically represent these ranges and their relative probabilities. Crack severity ranges are then obtained. The detection method is validated experimentally on a frame with scaled down dimensions. The fast Fourier transform is used to convert the time domain vibration signal into the frequency domain. Using higher order natural frequencies, two enhancement procedures for the detection method are devised and applied theoretically.

The alleviation of heating (in winter), cooling (in summer), artificial lighting and electricity use in office facilities is defined as a bioclimatic trend that offers sustainable building practice through a semi-transparent building integrated photovoltaic thermal envelope as a photovoltaic airflow window system. This thesis aims to produce synthesised design and strategies for the use of a proposed airflow window unit in office building in any given location and to maximise use of the renewable energy. Computational Fluid Dynamics (CFD), namely ANSYS Fluent 14.0, and ECOTECT have been employed to model the mechanical and natural ventilation of an office building integrated with a semi-transparent photovoltaic airflow window and the daylighting impact of various PV transparent degrees (15, 20, 25, 30 and 35 per cent) on the interior space, respectively, for winter and summer conditions. The use of such software has urged to establish a validation analysis a priori in order to ascertain the applicability of the tools to the targeted examination. The validation process involved a comparison of the results of CFD turbulence models, first, against benchmark and, second, against results of literature for identical component. The results of ECOTECT, in terms of daylight factor and illuminance level, were also compared against the results of Daysim/radiance, Troplux and BC/LC found in the literature. Excellent agreement was attained from the comparison of the results with errors less than 10 per cent. The study presents results of modelling of the airflow window system integrated into an office room for energy efficiency and adequate level of thermal and visual comfort. Results have revealed that the combination of mechanical and buoyancy induced flow spreads the heat internally warming the space to be thermally acceptable during the heating season whilst the mechanical convection is a main force for the cooling season. The thermal and visual comfort was compared for different PV airflow window transparent levels to determine the optimum PV transparency for the office space. Moreover, time-dependant and steady state conditions were imposed to predict the thermal and air behaviour for more elaborate investigation. The transient analysis was carried out, in sequential and individual base, according to the solar irradiance of each minute of working period, 8am-4pm (winter) and 5am-7pm (summer). The results obtained from transient and steady state, for both seasons, were compared and revealed negligible impact of transient effect. The PV electricity output was calculated from each transparency level under each condition, summer and winter (transient and steady). The predicted flow patterns, temperature distribution and the daylight factors in the room have been used to determine the most appropriate opening locations, sizes and system specifications for maintaining a comfortable indoor environment. The simulation investigation show that, for the proposed window model, optimum thermal and visual performance can be achieved from the PV transparency level of 20 per cent, during the heating season, and from the PV transmittance of 15 per cent, during the cooling season, where the PV output is highest. However the PV transparencies of 25, 30 and 35% can be reliable under altered conditions of operation.

This research addresses the problem of populating Building Information Model databases with information on building construction materials using a new classification method which uses multi-spectral laser scanning intensity and geometry data. Research in multi-spectral laser scanning will open up a new era in survey and mapping; the 3D surface spectral response sensitive to the transmitted wavelengths could be derived day or night in complex environments using a single sensor. At the start of this research a commercial multi-spectral sensor did not exist, but a few prototype level instruments had been developed; this work wished to get ahead of the hardware development and assess capability and develop applications from multi-spectral laser scanning. These applications could include high density topographic surveying, seamless shallow water bathymetry, environmental modelling, urban surface mapping, or vegetative classification. This was achieved by using from multiple terrestrial laser scanners, each with a different laser wavelength. The fused data provided a spectral and geometric signature of each material which was subsequently classified using a supervised neural network. The multi-spectral data was created by precise co-positioning of the scanner optical centres and sub-centimetre registration using common sphere targets. A common point cloud, with reflected laser intensity values for each laser wavelength, was created from the data. The three intensity values for each point were then used as input to the classifier; ratios of the actual intensities were used to reduce the effect of range and incidence angle differences. Analysis of five classes of data showed that they were not linearly separable; an artificial neural network classifier was the chosen classifier has been shown to separate this type of data. The classifier training dataset was manually created from a small section of the original scan; five classes of building materials were selected for training. The performance of the classification was tested against a reference point cloud of the complete scene. The classifier was able to distinguish the chosen test classes with a mean rate of 84.9% and maximum for individual classes of 100%. The classes with the highest classification rate were brick, gravel and pavement. The success rate was found to be affected by several factors, among these the most significant, inter-scan registration, limitation on available wavelengths and the number of classes of material chosen. Additionally, a method which included a measure of texture through variations in intensity was tested successfully. This research presents a new method of classifying materials using multi-spectral laser scanning, a novel method for registering dissimilar point clouds from different scanners and an insight into the part played by laser speckle interpretation of reflected intensity.

Climatic stress on buildings in hot-dry climates has long been negotiated by means of evaporative cooling, the origins of which could be traced back to Egypt and the Middle East. However, this millennia-old strategy needs to undergo much scrutiny in its design and implementation to meet the requirements of contemporary comfort standards for offices. The task is even more onerous if multi-storey buildings are considered. Acknowledging Cairo to be one of the most densely populated cities in the world and in light of the growing demand on high quality office space in recent years, it is anticipated that extending the application of evaporative cooling to medium and high-rise office buildings is imperative if this strategy is to be widely adopted as an alternative to conventional air-conditioning in Cairo given that existing research and applications are limited to low-rise buildings. This work proposes a four-stage plan to achieve that. The first stage entails the development of a generic prototype of the Passive Downdraught Evaporatively Cooled (PDEC) multi-storey office building that allows three distinct airflow patterns and two modes of operation to take place. The second stage makes use of analytic models for the initial sizing of the airflow components. The third stage assesses the performance of a base case model of the generic PDEC building in terms of bulk airflow rates, airflow distribution across the floors, internal thermal conditions, and relevant environmental costs using EnergyPlus, the whole building dynamic thermal simulation program with integrated airflow network modelling. The fourth and final stage is that of optimisation wherein the effects of varying a number of parameters on performance are established. The study shows that in comparison to free-running naturally-ventilated buildings, and depending on the thermal comfort model adopted, PDEC can potentially deliver comfort conditions for all occupied hours of the cooling season in Cairo. Buoyancy 'stack' forces alone generated by temperature differences can drive sufficient airflow rates without wind assistance, a scenario that is likely to occur in dense urban contexts. The study demonstrates the effectiveness' of dividing multi-storey buildings into isolated segments in terms of airflow (segmentation) and the benefits of extending PDEC operation beyond occupied hours. Changes in wind direction and speed were also considered and have shown to be of less significance if air inlets and outlets are properly located. Fine tuning of the building management system and adopting a more relaxed overheating criterion are key factors in limiting the increase in daily water consumption due to PDEC in light of the diminishing availability of sustainable water resources in the region. This study is the first to provide an understanding of how multi-storey office buildings in hot-dry climates can be designed and operated to incorporate PDEC as a viable alternative to AC. The novelty here lies not in the methodology which uses available models, but in the detailed investigation of flow rates, flow patterns, indoor temperatures, and water consumption.

Thermochromic (TC) windows were developed as a passive building component to improve indoor comfort and building energy conservation in place of traditional clear glazing systems. TC materials enable a spectrum-dependent regulation of solar radiation through windows stimulated by heat. When the temperature is higher than its transition temperature, less solar radiation, primarily in the near infra-red (NIR), will be admitted inside the building, reducing over-heating on hot days. Meanwhile, the TC materials tint to bluish or brownish appearance along with the transition. Most research about the commonly studied Vanadium dioxide (VO2) based TC windows was focused on fabrication methods and properties improvement of VO2 based materials, and a few numbers of studies investigated their energy performance when applied in buildings. Therefore, this research conducted a thorough investigation of TC windows applied in buildings, covering characteristic of TC windows, energy efficient, daylighting performance, and human response affected by different types of TC windows. Both simulation and experimental methods were carried out to explore the potential of TC windows. That aim is to provide a detailed guidance for the development of TC materials that are more flexible and acceptable to use in a practical building. The comprehensive analysis mainly consists of four parts: 1) simulation work on the evaluation of TC windows on energy efficient and daylighting, also the window size effects under five typical climates; 2) further evaluation of the potential of developed TC windows with enhanced capability of adjusting visible and NIR transmittance individually or cooperatively; 3) experimental investigation of the research hypothesis that TC tinted window has no effect on the human visual performance and subjective sensation, in a test room cubicle with a low level of simulated daylit (100lux); 4) further experimental investigation to detect the acceptance range of tinting for different windows at an indoor comfort illuminance level (350 lux). Findings show that compared with reducing the transition temperatures, improving capability of adjusting visible or NIR transmittance is more effective to improve both daylighting and energy performance. TC windows are more energy efficient when applied in buildings with large glazing area under cooling dominated climates. However, dynamic reduction of visible transmittance is required to decrease the risk of visual discomfort caused by over daylighting, especially for cities with lower solar altitude. Under a dark illuminance, bronze tinted TC windows were preferred subjectively, however, subjects had better visual performance under blue tinted TC window conditions. Sustained attention (i.e., focus on an activity for a long period of time) was not affected by TC window conditions (i.e., with correlated colour temperature (CCT) ranging from 3300 to 11000K), but further tinted bronze window was subjectively considered to improve concentration. Therefore, adjustment of visible transmittance is highly recommended for warm tinted TC windows. Simulation and lab experiment might have some limitation on this study, further work is suggested by carrying out further validation and employing more samples.

Ethylene-tetra-fluoro-ethylene (ETFE) is a synthetic fluoropolymer. In the form of ETFE-foil it is applied in building envelopes in a single layer or more commonly, as inflatable cushions composed of multiple layers. ETFE-foils are widely used as a lightweight building envelope where high translucency, low structural weight, and complex shape is essential. However, limited research in the field of thermal performance of ETFE-foil panels and spaces enclosed with it instigated this study. Therefore, this study investigated (I) the thermal behaviour of ETFE-foil materials and the thermal performance of spaces enclosed with ETFE cushion roofs, (II) used commercially available thermal simulation software to predict the thermal performance of spaces enclosed with ETFE cushion and glass roofs and compared this with actual monitored behaviour (III) identified strategies to improve the thermal performance of spaces enclosed with ETFE cushion roofs in current and projected climate scenarios; and finally (IV) proposed design recommendations of ETFE-foil panels/cushions as a building fabric components. Material properties were investigated in laboratory based experiments. Further data were collected from two custom built outdoor test-rigs equipped with single-, two- and three-layer ETFE-foil panels. Environmental data were collected from two case study buildings to evaluate the thermal performance of the spaces enclosed with ETFE-foil cushion roofs. In addition, building simulation was conducted using EDSL TAS version 9.3.3.b to further analyse the indoor thermal environment and compare with monitored behaviour. The study identified variable thermal-optical properties of ETFE foils caused by various percentages of fritted area and its pigment density. The results also identified that the thermal environment of the test-rigs was affected by the variations in the surface temperatures of ETFE-foils and the temperature of air volume between multiple ETFE-foils (in case of two and three layer panels) by convective and radiative heat transfer mechanisms. The results from the case study buildings identified that during hot summer days, indoor air temperature and temperature stratification was higher in the atrium space enclosed with three-layer ETFE-foil cushions compared to the space enclosed with two-layer ETFE-foil cushion covered with rain mesh. However, both of the spaces were overheated during the summer of 2015. To develop an accurate simulation model for ETFE cushion roofs, a novel approach of modelling was developed. The simulation model was validated and calibrated by comparing with measured data from test-rigs and case study buildings. A comparison of predicted results of the spaces enclosed with a multi-layer ETFE-foil cushion roof and a glass roof showed that the extent of overheating was high when spaces were enclosed with glass roofs. Among two-and three-layer ETFE-foil cushion and glass roofs, two-layer ETFE-foil cushions with 75% fritting and rain mesh effectively reduced air temperature and cooling load during the peak summer period. The findings of this study will enable designers to select and develop design strategies for applying ETFE-foils in building envelopes on the basis of thermal and optical requirements. The study also suggested to change the view of current design practice that only focused on current conditions; such as the use of ETFE-foils may require more adaptive approach to mitigate overheating problems in projected climate.

The energy demand in the oil- dependent 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. 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 the thermal properties 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 the thermal properties 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.