In the south of Algeria, many indigenous settlements have been built using local earth construction techniques, whilst in the north, despite the availability of suitable earth, only a few rural contemporary settlements have been built using ‘improved’ earth construction. This paper adopts a case study approach to examine and compare structural deficiencies of two earth-built housing settlements in different regions in Algeria. In the indigenous earth settlement in the south, where adobe was used in combination with local timber and stones, the dwellings exhibited many structural defects. Stabilisation of the soil and introduction of modern materials in the contemporary rammed earth settlement in the north, have not however helped produce structurally adequate dwellings. These also exhibited many cracks and de-bonding of rendering, and thus not fulfilling the requirements and aspirations of their occupants. The study concludes for a potentially successful earth building scheme there are inter-related factors that should be considered, including: selection of appropriate soil and construction technique, implementing suitable design, construction and post completion processes, availability of relevant skills and provision of adequate training on the construction technique.
Rooflights have become the common installations for industrial buildings to meet both the human health requirements for natural light and the need to save artificial lighting energy, especially for retail or distribution sheds that have big roof to floor area ratios and limitations of using glazing on side elevations. Since almost all of these buildings normally operate during daytime, an opportunity exists to save lighting energy by fitting automatic artificial lighting control. However, due to solar gains through the rooflights, the buildings are vulnerable to summer overheating. If overheating occurs regularly or over sustained periods, it will lead to the need for mechanical cooling, which inevitably results in more operational energy consumption in addition to the initial installation cost. To remedy this potential problem, natural ventilation through ridge openings is explored in this paper because it consumes almost no extra operational energy. Thermal modelling is therefore implemented with focus on influences of lighting control on energy consumption and effects of natural ventilation on reducing overheating. The modelling results indicate that lighting control can save lighting energy by 70% and the use of both ridge ventilation and lighting control can reduce overheating hours considerably, as internal heat is dissipated through the ridge openings and lighting heat gains are cut. In addition, converted from lighting and heating energy used, the overall CO2 reduction can reach 45% when both lighting control and ridge ventilation are applied. The findings from the study would encourage the use of rooflights for industrial buildings and would provide guidance on how to save operational energy while ensuring the thermal comfort inside the buildings.
There are growing concerns that the move to lightweight building construction in housing will lead to higher internal temperatures during the summer, particularly in the warmer future, due to lack of thermal mass. A dynamic thermal simulation study using Tas EDSL undertaken by Oxford Brookes University compared the thermal performance of current light, medium and heavy construction techniques for a typical UK three bedroom house. It found little difference in overheating performance for the three constructions in 1990s and 2050s (projected) weather scenarios. It is concluded that current practice in house building concedes little advantage to ‘traditional’ over modern construction techniques. Thermal mass can reduce overheating, primarily in the daytime, but it must be properly exploited by good design (good night ventilation, correct materials in the correct places). It is suggested that it is possible to optimise lightweight housing to provide similar thermal comfort levels during occupied hours using ventilation and shading.
The likelihood that buildings will be flooded and the frequency and severity of the inundation are calculated as part of the general flood predictions for urban and other areas. However, there is no reliable method to estimate the vulnerability of an individual building to damage from flooding. This makes it difficult for building owners and designers to calculate what appropriate measures should be taken to enhance resilience against floods.This paper, developed in the context of the current EC FP7 project FloodProBE, discusses the current estimation methods used in the UK, Germany, USA and Australia, and suggests ways to improve on these to make a model capable of estimating damage to individual buildings, particularly non-domestic ones. Flood damage to buildings and contents are dependent on a number of variables in relation to the flood events.The major variables are over-floor depth, velocity, rate of rise, debris, contaminants, frequency and duration of inundation and timing. Other variables relate to the building characteristics, such as structure, construction, materials and their drying characteristics, services and their locations, and the condition of the building prior to being flooded. A flood damage estimation tool that can deal with all these variables is likely to be very complex and difficult to manage, though oversimplification of the variables is likely to lead to inaccurate estimations.A balance must therefore be drawn between excessive complexity and accuracy. The output of the model should express the damage in cost form to be consistent with existing damage methodologies. This will enable calculations to be made in order to assess the cost/benefit analysis of installing flood mitigation/resilience measures to the building and/or its surroundings.