Investigation into energy performance of a school building in a hot climate: Optimum of window-to-wall ratio.

Global attention is currently focussed on developing techniques to improve the thermal performance of buildings to provide indoor comfort with minimum reliance on energy load. Several studies have investigated building facade, materials used and other factors involved in building design. The aim of this study is to examine the impact of thermal insulation, shading devices, window-to-wall ratio (WWR) and a combination of these factors in a prototype school building design in the warm climate city of Taif, Saudi Arabia. The study used various methods classified into two main phases. The first phase involved on-site observation where both thermal imaging and regular cameras were used to examine the influence of orientation on glazing as a baseline. The second phase involved advanced software investigations with 2D AutoCAD, 3D Revit and computer modelling for energy evaluation and daylight factor. A detailed framework was introduced to examine current school buildings and to improve the future designs of prototype school buildings. The study revealed that a combination of applying thermal insulation along with minimising WWR is required in existing buildings within hot and dry regions. Furthermore, it was recommended that WWR should not exceed 35%, 25% and 20% for northwest, southeast and southwest building facades, respectively

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The effect of the sun and its path on thermal comfort and energy consumption in residential buildings in tropical climates constitutes serious concern for designers, building owners and users. Passive design approaches based on the sun and its path have been identified as a means of reducing energy consumption, as well as enhancing thermal comfort in buildings worldwide. Hence, a thorough understanding regarding the sun path is key to achieving this. This is necessary due to energy need, poor energy supply and distribution, energy poverty and over-dependence on electric generators for power supply in Nigeria. These challenges call for a change in the approach to energy related issues, especially in terms of buildings. The aim of this study is to explore the influence of building orientation, glazing and the use of shading devices on residential buildings in Nigeria. This is intended to provide data that will guide designers in the design of energy efficient residential buildings. The paper used EnergyPlus software to analyze a typical semi-detached residential building in Lokoja, Nigeria, using hourly weather data for a period of 10 years. Building performance was studied as well as possible improvement regarding different orientations, glazing types and shading devices. The simulation results showed reductions in energy consumption in response to changes in building orientation, types of glazing and the use of shading devices. The results indicate a 29.45% reduction in solar gains and 1.90% in annual operative temperature using natural ventilation only. This shows a huge potential to reduce energy consumption and improve people’s wellbeing using proper building orientation, glazing and appropriate shading devices on building envelope. The study concludes that for a significant reduction in total energy consumption by residential buildings, design should focus on multiple design options rather than concentrating on one or few building elements. Moreover, the investigation confirms that energy performance modelling can be used by building designers to take advantage of the sun and to evaluate various design options

Energy Efficient Construction Methods in UK Dwellings

This paper examines the thermal performance of housing in the UK and the associated costs for different fabric construction methods of the envelope for a typical four bedroom detached house. The energy ratings were assessed using the UK Government’s Standard Assessment Procedure (SAP), which is based on the Building Research Establishment Domestic Energy Model. The capital costs were estimated from data published by the Building Cost Information Services applied to Leicester UK area in 2011. Through alterations to the dwelling fabric alone, a reduction of 30.1% in carbon emissions of the base property could be achieved. Standard methods proved to be as effective as alternative methods at reducing carbon emissions by 22.6% for an average capital cost increase of 9.1% against the base property. This was equivalent to an extra cost of £13.7 for each kg of CO2 emissions reduction. It was found that alternative methods could reduce carbon emissions by 20.5% for an extra cost of 18.4% over the base property. The optimum construction method that would help achieve the UK government’s carbon emissions target was also discussed. The paper also discusses the methods for improving energy efficiency in existing dwellings, using a typical solid-wall terraced house with a new single storey extension, as a case study. In this study, it was found that by increasing refurbishment costs by only 4.7% could result in carbon emissions reduction by 21.7%

Towards Energy Efficient Buildings in Nigeria: Challenges and Opportunities

The file attached to this record is the author's final peer reviewed version.The need to enhance people’s wellbeing by reducing CO2 emission has necessitated global efforts towards reducing energy consumption by buildings, which is responsible for nearly 45% of world’s energy consumption. Energy efficient design approaches have clear consequences on environmental protection and the wellbeing of urban populations. It is a viable means of reducing overdependence on electric generators and possible future retrofit of existing housing stock in Nigeria. Efforts towards achieving energy efficient buildings in this part of the world are not without challenges. Previous studies have revealed opportunities and possible challenges to energy efficiency in buildings in Nigeria. However, there seems to be scarce academic field data on this subject in the Nigerian context. Hence, this paper aims to identify benefits and possible hindrances to the realization of energy efficient buildings in Nigeria. This study adopted semi-structured interview involving 12 architects in Lokoja, Nigeria as the main approach for generating relevant data on this subject. Some of the limitations revealed by the interviewees include poverty, lack of awareness, lack of interest in local technologies and building materials, activities of non-professionals in the building industry and lack of effective regulatory bodies. This paper shows that there is enormous potential to improve people’s wellbeing and reduce carbon footprints if we can overcome the possible hindrances to achieving energy efficient buildings in Nigeria. The study concludes that energy efficiency in buildings can be achieved in Nigeria through strong awareness creation and collaboration among the stakeholders in the building industry

Optimising Residential Courtyard in Terms of Social and Environmental Performance for Ghadames Housing, Libya

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Vernacular architecture comes from a wealth of knowledge and experience of humans who were able to adjust to the surroundings and adapt to even extreme climate conditions. In fact many old traditional settlements may fail to functionally provide high indoor quality according to the modern building standards. However, these buildings are still seen as a good example of serving the purpose of locals’ social life and their ability to effectively respond to outdoor climate. Therefore, this work recognises the need to develop the courtyard concept to meet the social and environmental requirements of today’s housing conditions taking the advantage of traditional architecture of Ghadames. The work carried out methods of descriptive and simulation analysis to investigate the environmental performance of existing and proposed residential courtyards employing natural ventilation system in terms of thermal comfort conditions. The optimisation process of the courtyard design not only relied on methods of observation but also householders and professionals’ views were considered. Householders and professionals agreed that courtyard houses might be often linked to lower social classes but still serve most of social and climate purposes. The dynamic thermal simulation showed that indoor comfort temperature in a traditional courtyard was found to be at 34˚C. An optimisation design process was conducted to a courtyard building resulted in reducing the indoor comfort temperature to about 28˚C. Further results showed that the new design has improved the daylighting performance at 2.9% of average daylight factor. The work also outlined the applicability of using locally sourced building materials and their capacity to achieve high thermal performance particularly with reference to the use of organic date-palm fibre. It can conclude that the proposed design has integrated the passive climate design strategies to help achieving acceptable indoor comfort conditions and also sustainable features to further enhance locals’ social life

Focus on lived spaces and Identity: the Paradigm of the urban design with residential high-rises in England

Residential high‐rises find more and more often their place in central parts of the big British cities. Due to intrinsic characteristics of the typology, they are bound to be observed, evaluated and discussed. Therefor the purpose of this research is through observation of nine prominent high‐rise buildings in Manchester, Birmingham and London, subjected to rigorous analysis, to evaluate their ability to maintain identity and to be decisive part of the lived spaces around them. The research achieves this goal through four research questions: how is the design addressing the creation of strong identity of the researched buildings; are the identity‐creating features of the design contradicting major placemaking principles; what characteristics have the lived spaces around the residential high‐rises; what messages send the design of the lived spaces? The methodology relies on observational survey of the researched areas with the help of structured questions, to evaluate the external qualities of the residential high‐rises and their surroundings. Visual information can construct the basis to identify the shortcomings and the downsides of the examined project examples. It can provide insight on how can be improved imageability, legibility and the sense of place. In this connection, the results show that even though it was found that the high‐rises with their abstract form, memorable design and creative use of materials and architectural techniques maintain strong identity, the functional quality of the lived spaces around them is low, there are missing squares, gardens and playgrounds in close proximity and the only experience provided for the users is street life, which however exciting is too limited to only few activities such as eating, drinking, shopping or just walking and looking at limited typology of spaces. The implications of this research are that the British planners will address these problems and future projects will have better placemaking component

Towards resilient low-middle income apartments in Amman, Jordan: A thermal performance investigation of heating load

Energy security constitutes a major challenge for Jordan’s sustainable development. Space heating in Jordan represents ~61% of total residential energy consumption and dominantly involves portable un-flued kerosene and LPG stoves. Fuel combustion of such heaters generates poor indoor air quality and emits GHGs. Moreover, recent housing condition surveys show that the majority of dwellings in Jordan are very energy inefficient. This paper assesses the thermal performance of existing urban low-middle income apartments in Amman. This aim was approached through surveying 106 sample units and using EnergyPlus engine to calculate thermal performance of two representative apartments. Findings showed that ~75% of the apartments had thermally poor external envelopes. Analysis revealed that ~64% of heat loss can be attributed to exposed walls and roofs. The present research found that ‘thrift retrofitting’ will be inevitable in any effort in Jordan to deliver resilient low-middle income apartments

Sustainable design responses for residential high-rises

The file attached to this record is the author's final peer reviewed version. Open access articleSustainable design responses for residential high-rises is a viable topic with multiple answers. There are many separate types of researches in the literature on building envelope and applicable green technologies, but the opinion of leading architects so far has not been sought. The study discusses the sustainable design responses through the experience of twelve architects, informing the various parties of four important aspects of the sustainable design of residential high-rises. The methodology is based on an interview protocol with these four questions. The interviews were carried out in January-June 2016. The architects provided comprehensive data on the topic, including how to design residential high-rises in order to foster more social interactions, how to make these buildings more energy efficient and their views on renewable energy solution available. The implications from this study are that design professionals and the general public can use this insight for improving the design of residential high-rises in the near future

Sustainable issues in low-middle income apartments in urban Amman/Jordan: heating devices and health concerns

Energy security constitutes a major challenge for sustainable development of the Kingdom of Jordan. This has led the Ministry of Energy and Mineral Resources to integrate a comprehensive energy master plan for developing the energy sector by 2029. Of the total residential energy consumption, 61% is consumed for heating spaces. GHG emissions produced by domestic stock in Jordan are anticipated to increase by 59% by 2018. Most households heat their houses using traditional devices such as portable unflued kerosene and LPG stoves. Combustion of such heaters generates toxic by-products causing symptoms and illness among residents as a result of poor indoor air quality. This paper discusses aforementioned issues in view of urban low-middle income apartments in the capital Amman, aiming towards investigating types of stoves used and health implications associated with using them. A representative sample of 106 low-middle income households in urban Amman have been surveyed, through semi-structured interviews, to explore how they responded to the environmental conditions. Results showed that unflued kerosene and LPG stoves were used for heating spaces by around 39% and 89% of the total surveyed households, respectively. It was also found that almost 65% of them used more than one device for heating their apartments. Furthermore, around 50% of those households reported different health problems related to asthma which could partially be due to the use of these heating devices. The field study also showed that almost 75% of households lived in apartments constructed with external envelopes of cement hollow blocks leading to poorer fabric performance. The paper concludes with calling for thrift retrofit interventions for existing low-middle income apartments and raising inhabitants’ awareness towards the proper use of stoves. This would enhance their thermal comfort, reduce carbon emissions and help improve residents’ quality of life, which eventually would contribute in ameliorating related health issues

Simulation of Traditional and Contemporary Dwellings in Ghadames, Libya

A rise in temperature over summer in hot countries, such as Libya, may lead to thermal discomfort and profligate use of energy sources as a result of mitigation efforts. Buildings account for almost 45% of global energy consumption, and approximately 60% of primary energy use in Libya. The use of air conditioning systems have resulted in a sharp rise in energy consumption and CO2 emissions. Traditionally, bioclimatic design concepts have been applied and integrated into buildings in hot climates to reduce the demand of energy consumption, but increasingly less adapted designs of housings developed elsewhere are prevalent. This results in energy being excessively used in order to achieve human thermal comfort requirements. The purpose of this work is to investigate the environmental performance of naturally ventilated (NV) and air conditioned (AC) dwellings in Ghadames and the impact of bioclimatic concepts on energy use for future housing development. A range of EnergyPlus simulations were carried out to predict the indoor climate conditions and energy consumption of typical NV and AC dwellings considering different scenarios including the case of electrical power cuts. Findings revealed that traditional dwellings consume 66.1% less energy than contemporary dwellings. The thermal comfort surveys of Ghadames housing indicated that comfort temperature in NV buildings ranges between 24˚ to 32˚C and 22˚C to 26˚C in AC buildings in summer. Further findings from simulation showed that building fabric and form of traditional dwellings perform far better than contemporary dwellings in terms of solar heat gains, thermal performance of materials, land use and natural ventilation. The study concluded that consolidation of certain passive design features found in traditional dwellings of Ghadames and use of appropriate architectural design and elements can help achieve zero energy housing, taking into account local community needs and future developments