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This research aims to improve the accuracy of a green roof thermal simulation by linking the moisture transfer in the substrate with the conduction heat transfer. The improved simulation is divided into two phases, which are the absorption and evaporation. For the absorption, this research applies the Sharp Front theory to predict the position of the boundary between the saturated and dry zones. The theory of evaporation from a porous medium is used to predict the moisture content in different substrate layers during evaporation. After the moisture content in each layer is determined, this moisture content data can be converted into thermal conductivity, and the time dependent effective thermal resistance can be calculated, which is used in the conduction heat flux calculation for the thermal simulation. Having developed the simulation of heat conduction through the substrate as a result of absorption and evaporation, the results are applied to a case study building to compare a green roof substrate in three moisture conditions (dry, saturated, and the varying simulated moisture content). The results confirm that it is possible to include the effect of water absorption and evaporation from a green roof substrate in the thermal simulation of building performance using the two theories. The improved simulation makes it possible to model an intensive green roof, where the depth of the substrate is likely to produce a greater distribution of moisture content in service. The simulation is an improvement over previous models and the case study shows that, assuming the substrate to be dry (as in existing models), underestimates the heat loss, whilst assuming it is saturated slightly overestimates the heat loss. The small, but significant, effect of moisture variation in service is important for designers of green roofs. If it is not taken into account it would be preferable to assume that the roof is continuously saturated as this gives a conservative estimate of the heat loss from a building.

This research focused on the soundscape design of a wide range of small to medium sized water features (waterfalls, fountains with upward jet(s), and streams) which can be used in gardens or parks for promoting peacefulness and relaxation in the presence of road traffic noise. Firstly, the thesis examined the audio-visual interaction and perceptual assessment of water features, including the semantic components and the qualitative categorisation and evocation of water sounds; and secondly, the thesis investigated the effectiveness of the water features tested in promoting relaxation through sound mapping. Different laboratory tests were carried out, and these included paired comparison tests (audio-only, visual-only and audio-visual tests), semantic differential tests, as well as tests aimed at the qualitative categorisation and evocation of water features. Sound maps of the water generated sounds were developed through the use of propagation models based on either point or line sources. Three acoustic zones (‘water sounds dominant zone’, ‘optimum zone’ and ‘RTN dominant zone’ (RTN: road traffic noise)) were defined in the maps as the zones where relaxation/pleasantness can be promoted over a 20 m × 20 m area for different road traffic noise levels. Paired comparisons highlighted the interdependence between uni-modal (audio-only or visual-only) and bi-modal (audio-visual) perception, indicating that equal attention should be given to the design of both stimuli. In general, natural looking features tended to increase preference scores (compared to audio-only paired comparison scores), while manmade looking features decreased them. Semantic descriptors showed significant correlations with preferences and were found to be more reliable design criteria than physical parameters. A principal component analysis identified three components within the nine semantic attributes tested: “emotional assessment,” “sound quality,” and “envelopment and temporal variation.” The first two showed significant correlations with audio-only preferences, “emotional assessment” being the most important predictor of preferences, and its attributes naturalness, relaxation, and freshness also being significantly correlated with preferences. Categorisation results indicated that natural stream sounds are easily identifiable (unlike waterfalls and fountains), while evocation results showed no unique relationship with preferences. The results of sound maps indicated that small to medium sized water features can be used mainly in environments where road traffic noise levels are equal or lower than 65 dBA.

There is a growing need to curtail the carbon emissions in the globe in order to achieve the climate stabilisation goals based on the climate change threat. And as such, different initiatives and schemes of Government have targeted a number of policies at reducing energy and carbon emissions targets with the housing sector of the economy not an exception. In order to explore the feasibility of achieving carbon emissions reduction targets within the housing sector of the UK, the research views the issue of household energy consumption and carbon emissions as complex sociotechnical problem involving the analysis of both the social and technical variables. This thesis therefore describes the development of the system dynamics based model to capture and solve the problem relating to the future profiles of household energy consumption and carbon emissions by providing a policy advice tool for use by the policy makers. In order to investigate the problem, the research adopts the pragmatist research strategy involving collection of both qualitative and quantitative data to develop the model. The developed model has six modules, which are: population/household, dwelling internal heat, occupants’ thermal comfort, climatic-economic-energy efficiency interaction, household energy consumption, and household CO2 emissions. In addition to the ‘baseline’ scenario, the developed model was used to develop four illustrative scenarios of household energy consumption and carbon emissions; which are: ‘efficiency’ scenario, ‘behavioural change’ scenario, ‘economic’ scenario, and ‘integrated’ scenario. The ‘efficiency’ scenario generally considers the effects of improvements in energy efficiency measures on household energy consumption and ultimately on household carbon emissions. Additionally, the ‘behavioural change’ scenario tries to model the effects of occupants’ change of energy consumption behaviour on household energy consumption and carbon emissions profile. The ‘economic’ scenario assumes a case of policy change by Government favouring energy prices reduction, thereby reducing the energy bills payable by the householders and its consequences on household energy consumption and carbon emissions. And the ‘integrated’ scenario combines the assumptions in the first three scenarios and then analyses its effects on household energy consumption and carbon emissions. The ‘baseline’ results indicate that about 49% savings in carbon emissions by the year 2050 below the base year of 1990 are possible. Additionally, the results of the developed model for all the illustrative scenarios indicate that carbon emissions savings of 46%, 55%, 58%, and 63% below the base year of 1990 are possible from the ‘economic’, ‘efficiency’, ‘behavioural change’, and ‘integrated’ scenarios respectively. The research concludes that it is unlikely for any of the scenarios by its own to meet the required legally binding reductions of 80% cut in carbon emissions by 2050 unless this is vigorously pursued. The unique contribution of the research is the development of a model that incorporates socio-technical issues that can be used for decision making over time.

This research was commissioned by Historic Scotland, to ascertain what, if any, characteristics specific to traditionally constructed (stone masonry) dwellings in Scotland could impact on the result of an energy assessment. The research uses five case study dwellings, whose energy consumption has been assessed using three separate calculation methodologies: the two Government-accredited steady state methodologies SAP and RdSAP, in addition to a dynamic simulation using the IES Virtual Environment. The research finds primarily that traditionally constructed dwellings use more energy than the UK average, and that certain aspects of the steady state calculation methodologies give erroneous results. These errors are either specific to stone masonry dwellings through application of assumptions with respect to thermal storage and movement, or specific to Scottish dwellings through application of UK average climate variables. Furthermore, there are significant challenges to using dynamic simulations for these dwellings, which may not outweigh the benefits of perceived accuracy by the occupant. Therefore, the research concludes that the steady state methodologies should continue to be utilised, but with the awareness that the methodologies have limitations.

Pressure is growing upon non-domestic building owners and occupiers to measure and improve the energy performance, and associated carbon emission levels, of the portfolio in which they operate. In line with this, the need for energy-led refurbishment of existing buildings is increasingly evident, with approximately 60% of the current building stock expected to still exist in 2050 and less than 1% being replaced annually. However, energy-led refurbishment of existing non-domestic property faces a number of barriers, including an ill-defined decision-making process and a lack of low carbon skills required to guide building owners in this complex transition. This thesis examines first, the need for a re-alignment of disciplines within the construction industry to fulfil the growing requirement for low carbon skills, specific to energy-led refurbishment. A comprehensive desk study was undertaken, evaluating the competencies of the established construction industry professions, as defined by their governing bodies. This was supported by structured interviews with users of large, nondomestic property and industry professionals to establish whether a need existed and how they proposed it be fulfilled. A deficiency in expertise was identified, and from this a competency specification for professionals leading energy-led refurbishment in existing, non-domestic property has been developed. Second, this thesis explores the different forms of automated decision support within the construction sector, identifying opportunities for a structured decision-making approach to energy-led refurbishment. An optimum decision support tool (DST) process was proposed, consisting of seven steps from assessment of the existing building’s state through to continuous evaluation and improvement of the refurbished building. A key module within this process was developed in detail to address the complex multiple attribute decision making (MADM) approach required during selection of energy performance improvement measure (EPIM). A set of assessment criteria, addressing a variety of performance characteristics, was designed using an online Delphi survey with a select group of ‘energy in buildings’ experts. The criteria range from short term impact (EPIM installation) to long term impact (EPIM operation and disposal) upon the existing property’s performance. Subsequent weighting of the assessment criteria in terms of their relative importance was undertaken using the same expert group through a paired comparison survey methodology. This revealed the relative importance of each criterion, consequently aiding prioritisation of EPIMs within the optimum DST and supporting decision-making.

This research establishes the concept of ‘Green Maintenance’ modelling for historic masonry buildings. It recognises the important role of maintenance and repair in reducing embodied carbon expenditure, thus minimising the Environmental Maintenance Impact (EMI) typically associated with the deterioration of external stone masonry walls. The model was developed using a mathematical framework, and it generated results described in terms of EMI. This model utilises life-cycle assessment (LCA) ‘cradle-to-site’ over a selected maintenance period. The work evaluates embodied carbon expenditure from different stone masonry wall repair techniques for historic masonry buildings during their maintenance phase. It was discovered that embodied carbon expenditure for these repair techniques are highly influenced by the number of maintenance interventions, longevity of repairs, total wall surface repaired (m2), the embodied carbon coefficient value (‘cradle-to-gate’) and kg/km emission factors (‘gate-to-site’) associated with materials and repair processes. Based on the EMI in terms of embodied carbon expenditure generated from the results of ‘Green Maintenance’, the efficiency of stone masonry wall repair techniques can be determined. This not only aids in maintenance decisions making processes, but also contributes in substantiating the philosophical defensibility and sustainability of interventions. In the broader sense, this model is not simply confined to masonry and will be of use to those entrusted with the repair of other elements and components.

In the context of the global trend towards reducing the carbon footprint of buildings, the design team must make decisions, which have major consequences on the carbon footprint. This should be during the early stages of the building design process, as changes made later on can be costly. Although Life-Cycle Assessment (LCA) is the ‘gold standard’ method to evaluate the design from 'cradle to grave'. The lack of detail available on the concept design makes LCA very difficult if not impossible. Unfortunately, this is the very stage at which decisions are made that have a most significant influence on the life cycle. In order to support designers, a database of LCA case studies data is needed, accessible to designers and decision makers, and giving guidance on specific areas of significant impact, on which they can concentrate to reduce the building’s total impact. The work in this thesis sets out to address this need. This thesis presents life-cycle case studies of two new-build offices in Scotland that could be used as guidance during the concept stage of the design process. This is achieved by modelling the carbon emissions of different life-cycle stages, and different building materials and components used in building activities. The hypothesis that the current trend of office building in Scotland produces buildings which are relatively lower in their emissions than those reported in the literature is tested by a full life-cycle assessment of two new-build offices in Edinburgh. Scenario and sensitivity analysis is used to assess the future of office buildings in Scotland. The carbon dioxide emissions of the two case study buildings, when normalised according to floor area, are similar and lie towards the lower end of the range of worldwide data reported in the literature. Sensitivity analysis shows that the life cycle results are affected by changes in design parameters, and are highly sensitive to the assumptions about the future made at the design stage, such as future changes in electricity generation over time, refurbishment and recycling. Large savings in carbon dioxide emissions can result from small changes at the design stage, such as glazing ratios and the provision of parking. Some of these are fields for future research and development.