Over the past two decades, more than 30 evacuation models have been developed to reproduce people’s movement patterns in evacuation. However, evacuation models cannot assess whether one building is better than another in regards to evacuation wayfinding. There exist techniques that attempt to compare different buildings for evacuation complexity. However, these graph measures are primarily used to measure the relative accessibility of different locations in a spatial system and were not generated for the purpose of comparing the complexity of different buildings. Currently only one method exists, Donegan’s method [DT98] [PD96] [DT99], which can be applied to compare building for evacuation ability. However, this technique is severely limited to specific building layouts and only considers connectivity. Taking the Donegan’s method as a first step, this thesis extends this algorithm to obtain a new Distance Graph Method, which considers travel distance as well as being able to be applied to graphs with circuits. Then a further building complexity measures is presented, the Global Complexity (PAT) method. This is shown to be a valid measure which considers additional important factors such as wayfinding time, travel distance and the areas of compartments. The Distance Graph Method and Global Complexity (PAT) methods are based on a room graph representation which does not have the descriptive power to describe the actual routes taken during the wayfinding process. To resolve this drawback a further method is presented which utilises a ‘route-based graph’ that has the ability to represent the real route that an evacuee will take during the wayfinding process. Furthermore the Distance Graph Method and Global Complexity (PAT) methods assume a “worst state” calculation for the nodal information. This means for buildings with more than one exit these methods calculate a global building complexity according to a mathematical formula, which considers all exits separately. To address these problems, the final method, Complexity Time Measure, is presented, which is based around a number of wayfinding behaviour rules over a ‘route-based graph’ representation. This addresses the question: ‘If an occupant is positioned at a random location within a building, on average how long does the occupant need to spend to find an available exit?’ Hence, provides a means to compare complex buildings, with circuits, in relation to evacuation capability.

The contributions to knowledge documented in this doctoral thesis are two-fold. The first contribution is in the application of a new biomimetic design tool called BioTRIZ. Its creators claim it can be used to facilitate the transfer of biological principles to solve engineering problems. The core case-study of this thesis documents how this tool was used to frame and systematically explore low-energy solutions to a key technical problem in the underdeveloped field of radiative cooling. Radiative cooling is a passive mechanism through which heat from a building can be rejected to the sky – an abundant but underused natural heat sink. Published in the Journal of Bionic Engineering, the study was the first independent application of BioTRIZ in the academic literature. The second contribution to knowledge is in the design, development and testing of the most promising biomimetic concept to come out of the BioTRIZ radiative cooling study. ‘Heat-selective’ insulation gives a roof mass a cool view of the sky because integrated pathways focus and channel longwave thermal radiation through it. It is biomimetic because it achieves infrared transparency by adding structural hierarchy to the component, rather than manipulating the properties of the material itself. Test panels on a rooftop in central London cooled to between 6 and 13 degrees below ambient temperature on May and April nights. Radiative cooling powers of between 25 and 70 W/m2 were measured when plates were at ambient temperature. Daytime radiative cooling below ambient temperature occurred when clouds blocked direct sunlight. Radiative cooling power was increased by 37% using reflective ‘funnels’. Two additional BioTRIZ analyses are presented as minor case studies. They each attend to a key technical problem in the field of passive thermal energy storage in buildings. They serve to illustrate the type of results that can be expected from using BioTRIZ during low-energy building design.

Relevant research has identified that high level of building emergency casualty (e.g. due to fire) has direct link with the delayed evacuation especially in residential and high-rising buildings. The traditional fire drill can only passively identify some bottleneck for evacuation after the building has been constructed and under its operation stage; and end-users normally lack of means to be effectively involved in the decision making process in the first place (e.g. building emergency planning and design) and lack of cost-effective and convenient means to be well trained about emergency evacuation at later operation stage. Modern building emergency management research has highlighted the need for the effective utilization of dynamically updated building emergency information. Building Information Modelling (BIM) has become the information backbone which can enable integration and collaboration throughout the entire building life cycle. BIM can play a significant role in building emergency management due to its comprehensive and standardized data format and integrated life cycle process. This PhD research aims at developing an end user oriented BIM enabled virtual environment to address several key issues for building emergency evacuation and planning. The focus lies on how to utilize BIM as a comprehensive building information provider to work with virtual reality technology to build an adaptable immersive serious game for complex buildings to provide general end users emergency evacuation training/guides. The contribution lies on the seamless integration between BIM and a serious game based Virtual Reality (VR) environment, which enables effective engagement of end-uses. By doing so potential bottlenecks for existing and new buildings for emergency evacuation can be identified and rectified in a timely and cost-effective manner. The system has been tested for its robustness and functionality against the research hypothesis and research questions, and the results show promising potential to support more effective fire emergency evacuation and planning solutions.

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International Energy Agency Solar Heating & Cooling (IEA SHC) programme states the fact that space/water heating and cooling demand account for over 75% of the energy consumed in single and multi-family homes. Solar energy technology can meet up to 100% of this demand depending on the size of the system, storage capacity, the heat load and the region’s climate. Solar thermal collectors are particular type of heat extracting devices that convert solar radiation into thermal energy through a transport medium or flowing fluid. Although hybrid PV/T or thermal-alone systems offer some advantages to improve the solar heat utilisation, there are a few technical challenges found in these systems in practice that prevented wide-scale applications. These technical drawbacks include being expensive to make and install, inability of switching already-built photovoltaic (PV) systems into PV/T systems, architectural design etc. The aims of this project, therefore, were to investigate roof integrated solar thermal roof collectors that properly blend into surrounding thus avoiding ‘add on’ appearance and having a dual function (heat absorption and roofing). Another objective was to address the inherent technical pitfalls and practical limitations of conventional solar thermal collectors by bringing unique, inexpensive, maintenance free and easily adaptable solutions. Thus, in this innovative research, unique and simple building integrated solar thermal roof collectors have been developed for heating & cooling applications. The roof systems which mainly based on low cost and structurally unique polyethylene heat exchanger are relatively cost effective, competitive and developed by primarily exploiting components and techniques widely available on the market. The following objectives have been independently achieved via evaluating three aspects of investigations as following: • Investigation on the performance of poly heat exchanger underneath PV units • Investigation on the performance of a Building Integrated PV/T Roof ‘Invisible’ Collector combined with a liquid desiccant enhanced indirect evaporative cooling system • Investigation on the build-up and performance test of a novel ‘Sandwich’ solar thermal roof for heat pump operation These works have been assessed by means of computer simulation, laboratory and field experimental work and have been demonstrated adequately. The key findings from the study confirm the potential of the examined technology, and elucidate the specific conclusions for the practice of such systems. The analysis showed that water temperature within the poly heat exchanger loop underneath PV units could reach up to 36°C and the system would achieve up to 20.25% overall thermal efficiency. Techno-economic analysis was carried out by applying the Life Cycle Cost (LCC) method. Evaluations showed that the estimated annual energy savings of the overall system was 10.3 MWh/year and the cost of power generation was found to be £0.0622 per kWh. The heat exchanger loop was coupled with a liquid desiccant enhanced indirect evaporative cooling unit and experimental results indicated that the proposed system could supply about 3 kW of heating and 5.2 kW of cooling power. Lastly, the results from test of a novel solar thermal collector for heat pump operation presented that the difference in water temperature could reach up to 18°C while maximum thermal efficiency found to be 26%. Coefficient Performance of the heat pump (COPHP) and overall system (COPSYS) averages were attained as COPHP=3.01 and COPSYS=2.29, respectively. An economic analysis pointed a minimum payback period of about 3 years for the system.

This portfolio of published research contains nine papers and assesses the life cycle environmental burdens of energy technologies and buildings. Several analytical tools were used but these all fall under the umbrella of environmental life cycle assessment (LCA), and include energy analysis, carbon appraisal and the consideration of other environmental issues. The life cycle of all products starts with an assessment of embodied impacts. The current author has completed significant research on the embodied carbon of materials. This includes the creation of a leading embodied carbon database (the ICE database) for materials which has been downloaded by over 10,000 professionals and has made a significant contribution to knowledge. This portfolio of work includes analysis on methods for recycling in embodied impact assessment and LCA. This is an influential topic and therefore appears in two of the publications. The ICE database was applied by the current author to over 40 domestic building case studies and an embodied carbon model for buildings was created from these. The latter was used to provide benchmark values for six types of new houses in the UK.The portfolio of work then progresses to full LCA of energy systems. LCA is used to assess the embodied impacts versus operational impacts of 11 kV electrical cables. In this case embodied impacts were not significant and preference should be given to reducing electrical losses in the cables. The tool of LCA was then applied to a national electricity network. It revealed that Lebanon had a particularly poor centralised electricity network that was both unreliable and unsustainable with high impacts in all environmental categories. The final paper in this portfolio is on Building Integrated PV (BIPV) and brings together all aspects of the current author’s work and knowledge. It considers embodied burdens, electricity generation and BIPV can replace roofing materials.

Higher education institutions (HEIs) in England occupy approximately 25 million m2 of gross space. Many of the buildings in these estates were constructed when thermal standards were far lower than those specified today. Estate managers now need to consider how to manage existing buildings in order to meet new requirements for occupants’ comfort, energy efficiency and greenhouse gas emission targets. The choice of whether to refurbish, or demolish and rebuild, requires a critical analysis of a range of environmental, social and economic issues. To this end, the Association of University Directors of Estates (AUDE) developed a toolkit that identifies crucial issues to be taken into account to make this choice clear. However, while this toolkit represents a considerable step forward in the decision-making process, it does not incorporate the projected impact of climate change and its uncertainty. Thermal modelling analysis of an existing naturally ventilated higher education building, built in 1974, suggests that projected changes in the UK climate will significantly increase building overheating. Therefore, it is essential that the impacts of climate uncertainty now and in the future are considered when refurbishment options are assessed. A framework has been developed, taking climate change impacts into consideration, which ranks different refurbishment options according to the following performance criteria: thermal efficiency, environmental impact and cost effectiveness. Whilst the use of single performance criterion results in different ranking of refurbishment solutions in this case study, the use of high performance glazing is the best overall single refurbishment solution. In general a combination of high performance glazing, wall insulation and the use of external shading together are considered to be the best combined refurbishment solution. External shading is the least effective single refurbishment solution.

This thesis deals with the influence of fire on the behaviour of steel concrete composite floors. A theory has been developed to calculate deflections during the fire and the ultimate strength of the composite floor under such conditions. The solution is based on the finite difference method. It takes temperature-dependent material properties into account. The method of analysis comprises two parts; the first is thermal analysis, enabling temperatures to be calculated as a function of fire exposure time. The second is strength analysis for calculating the strength of composite floor with material properties affected by temperature. For the heat flow analysis, the cross-section is divided into mainly rectangular elements. Sloping boundaries are approximated by triangular elements. The heat transfer from the fire to the surface is considered as well as heat conduction to the neighbouring points. At internal points, heat conduction to all the neighbouring points is considered. To calculate the deflections, the floor is divided into a two-dimensional mesh. The deflections are calculated for each mesh point based on orthotropic plate theory. The differential operators are replaced by the finite difference formulae. This reduces the governing differential equation into a system of linear algebraic equations. To calculate the plate rigidities, it is necessary to find curvatures for all mesh points in the two planes using finite difference operators. The thermal strains are superimposed on the mechanical strains associated with curvatures to find the net strains, and then stresses are calculated using the non-linear temperature dependent stress-strain curves. Integrating the stresses, the internal stress resultants are calculated. The above method has been programmed in Visual Basic. To validate this method, a comparison with a number of fire tests has been carried out, for both thermal and mechanical behaviour. The temperatures at comparable points are generally close to each other. Comparisons have also been carried out for calculated mid-span deflections by this method and the published test results. The results show excellent correlation between the tests and the new method. A parametric study has been carried out on floors with different boundary conditions when subjected to in-plane forces for two fixed and simple ends. Comparison of mid-span deflections between the fixed and simple end conditions has shown that fixed edges have better fire resistance than simply supported when not subjected to in-plane forces. It has found that in-plane forces had little effect on deflection rates at initial stages of the fire. These only appeared at later stages. When subjected to in-plane forces in one direction only the floor showed better response. The conclusion from the parametric study is that in-plane forces at different edges play a significant role in the behaviour, as the surrounding structure provides restraint increasing the fire resistance of the structure within the fire compartment.

This thesis presents the results of an experimental investigation into the strength of brickwork under biaxial tension-compression. Since there is insufficient experimental evidence available on the strength of brickwork under biaxial stress to explain the behaviour of brick masonry walls under in-plane loads, experiments were carried out on one-sixth scale model brickwork panels under uniform stress conditions. An idealized failure surface is suggested based on experimental results, and the effect of shear bond strength and tensile bond strength on the results is discussed. An iterative plane stress finite element computer programme incorporating the above information is used to simulate the in-plane behaviour of brickwork. Brickwork is treated as an elastic, isotropic material with limited capacity when stressed in a state of biaxial tension-compression. The model reproduces the non-linear behaviour of masonry produced by progressive cracking. Shear wall tests have been used to test the validity of the analytical model. Sensitivity analysis of the elastic constants used in the model are performed to illustrate their influence on the calculated stresses. The influence of the stress distribution on shear wall behaviour, and the derivation of a failure criterion for local failure in masonry shear walls, are described. This criterion, in terms of the vertical stress and shear stress at a point, has been derived for particular values of horizontal stress from the three dimensional surface mentioned above. The effect of the shape of the specimen, testing technique, and boundary conditions on the shear strength of masonry panels is discussed.

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