An evaluation method for daylighting quality in buildings under clear sunny skies.

In buildings, daylight is a commonly-used source of wellbeing, aesthetic delight and energy efficiency. Daylight is therefore one of the main parameters considered in the design of buildings. Methods used by architectural designers may be quantitative and/or qualitative. In general, these methods feature detailed figures, charts and graphs; however, there are two criticisms of how these methods handle daylighting. Firstly, a figure or a chart is only really useful for evaluating the final outcome of a design, not helping an architect in the earlier stages of the design process. Secondly, these sorts of methods are based on theoretical models in which the building's occupants and their preferences or behavioural needs are either ignored or excessively generalised. In addition to this, some architects base their daylighting designs on their own ideas that actually conflict with those of the building's intended occupants. In spite of this, various research has shown that accounting for the preferences and behaviours of occupants are major factors in the success of a building project. It is therefore very important for architects and daylighting designers to better understand these factors, and to incorporate them into the earliest stages of their designs. Occupants' preferences should be translated into terms of relationships between the components of the architectural space (e.g. envelope, window, furnishings, colours and finishes) and the specific contextual aspects of the building's usage (e.g. climatic and socio-cultural environments). More research in this area is therefore required, particular within contexts that have previously received relatively little attention, such as hot, dry regions with clear, sunny skies. To this end, a first step is to decide on the most appropriate method for evaluating daylighting quality in buildings - subjectively, from the point of view of the occupants; or objectively, using strictly physical/statistical measurements. Surveys are generally chosen for large case studies or for experimental research, but the post-occupancy evaluation (POE) appears to be the most suitable method for this particular research. This method was therefore applied in the evaluation of several aspects of a building, and has since been extended to include daylight as a parameter. The daylighting POE method was used to assess two kinds of contemporary building in southern Algeria: offices; and flats within mutli-family housing projects. This paper presents the reasoning for - and implementation of - this method

Office buildings' daylighting design in hot arid regions: forms, codes and occupants' point of view.

In hot and arid regions, contemporary designers need more daylighting related information in order to achieve an environmental friendly and energy efficient architecture design. This paper presents the results of a Post Occupancy Evaluation research undertaken in an office building in the city of Biskra, Algeria. This POE aims to fill this lack by providing practical information. The field work took place during summer in the building of La Caisse Nationale des Assurances Sociales (a major state insurance company). Firstly, the study results presents the different shape and photometric ratios revealed by the field survey and discuss them according to the prevailing norms and design guidelines recommended for buildings under clear sunny skies. Secondly, it exposes the occupants‘ perception and behavior and their relationships to the shapes, photometric values and relevant standards for the hot arid context

The impact of sunlight and daylight on the dwelling's occupancy: case of the hot dry regions of Algeria.

It is often asserted that the sun and traditional dwellings were in a perfect harmony, whereas the built environment produced in the last fifty years has in fact marginalized most of the climatic factors. Increasingly, an effort is being made to recover this lost relationship in the form of energy conscious, passive solar and high environmental quality designs. One of the main issues is the use of sunlight and daylight to light up building interiors. Natural light has obvious health benefits and is simultaneously helpful for energy efficiency. Several investigations have demonstrated that sunlight and daylight are well appreciated by building occupants; moreover, these investigations have proved that lighting standards are insufficient, and that there are important non-physical factors involves (e.g. psychological and cultural factors). These non-physical factors vary depending on their climatic and cultural contexts, on the season of the year and time of day, and on the specific people and tasks invovled. It is therefore important to avoid excessive generalisations. This study focuses on the context of a hot, arid region with a sunny sky. In such environments, sunlight penetration is combined with thermal discomfort and glare problems; as a result, the attitudes of building occupants are different from other environmental contexts in which the presence of sunlight is more desirable. This paper aims to study the impact of sunlight and daylight on the affective relationship between a home and its occupants, by analysis of a building's frequency of occupancy. In this work, the home is considered as the behavioural setting and the vernacular dwellings of the southeastern region of Algeria present the focus of this research. The preliminary outcomes presented in this paper are part of broader research investigating people's reactions and attitudes towards various daylighting and sunlighting strategies, in different working and living spaces within an Islamic culture

Occupants and daylight in office buildings under sunny skies.

It is expected that the climate of North Africa, one of the hottest regions of the world, will become still more extreme due to the effects of global warming. This would result in higher energy consumptions for cooling purposes in buildings. Daylight could be an efficient energy saving strategy as well as for enhancing productivity. This research aims to explore the relationships between occupants and climatic parameters, with a focus on sunlight and daylight. Previous research revealed the importance of daylighting design to office occupants. The POE method was used to assess the daylighting quality in South Algerian contemporary buildings where the sky is sunny and clear almost year around. This assessment investigates an office building that is over-protected against sunlight and aims to identify the occupant’s reaction (behaviour and satisfaction) to daylighting design. The results presented in this paper are the occupant’s appreciation of : i) The importance of daylight, ii) The illuminance levels under which the occupants are working, iii) The sunlighting control means operated by occupants, and iv) The current sittings (desks position and distance) of occupants in relation to the window location

Sunlight and daylight in the traditional built environment: case of the hot arid regions.

Sunlighting is an essential consideration in order to achieve an architecture that is environmentally conscious in hot arid regions. The aim of this chapter is to identify the sunlighting strategies and their resulting typology in some urban spaces, and different types of buildings and constructional details, as developed in the traditional hot and arid regions of the Islamic world. Various sunlighting strategies highlight inspiring elements with prominent environmental and energy savings potential. It is noted that the interest on traditional sunlighting and daylighting strategies arises first from its great availability throughout the year. Also, there is an ancestral tradition of adaptation to the intense sunlight with spiritual values associated to it. The chapter is based on analytical studies and classification of sunlighting strategies, which is a part of a broader research including people's reactions and attitudes toward various daylighting design strategies in different working and living spaces

Sunlight in the traditional dwellings of Algeria.

This paper aims to study the impact of sunlight and daylight on the dwelling's design in Algeria. The approach used for this purpose is the theory of structuration. In this work, the home is considered as the behavioural setting and five case studies are investigated from the coastal area of Algeria to its Sahara desert: traditional houses of Algiers, Kabylie, Constantine, Aures and Ghardaia. The preliminary outcomes presented in this paper are part of a broader research including people's reactions and attitudes, of an Islamic culture, towards various daylighting and sunlighting strategies in different working and living spaces

Environmental assessment of energy efficiency improvements in historic buildings: solid wall insulation.

Since the elaboration of the Leipzig Charter on Sustainable European Cities in 2007, energy retrofit has become one of the priorities for the European Union. However, to achieve a sustainable development of the built environment, we need to not only address the energy consumption in the operational phase but also the environmental aspects associated with the production of the materials applied in the energy retrofit measures. In this case the sustainability is evaluated by comparing the embodied impacts generated during the entire life cycle of the materials with the energy use reduction achieved due to the thermal performance improvement

Sunlighting and daylighting strategies in the traditional urban spaces and buildings of the hot arid regions.

In hot arid regions, sunlighting is an essential consideration to achieve an environmentally conscious architecture. This paper aims to identify the sunlighting strategies and their resulting typology in some urban spaces, different types of buildings and constructional details as they have been developed in the hot and arid regions of the Islamic world

Engineering assessment made easy: the 'Energysave' approach.

Whilst naturally ventilated buildings are currently considered to be the ideal solution to low energy design there remain a large proportion of buildings for which air conditioning offers the only practical solution. This project is intended to provide a means to assess design options for such buildings at a very early stage in the design and in particular address the selection of the most appropriate system. The form of the interface is still developing and while it has been demonstrated to designers no third party tests have yet been carried out. This paper reports on a project that aims to show that a general description of the building can be used to generate sufficient data to drive a valid analysis using a detailed thermal model at the early sketch stage of the design process. It describes the philosophy, methodology and the interface developed to achieve this aim. The interface guides the user through the input process using a series of screens giving options for keywords used to describe the building; comprehensive default data built into the software are then attached to these keywords. The resulting data file is a building description that is the best possible interpretation of the design intent. This can then be used to assess options and guide towards a final design

A risk based methodology to assess the energy efficiency improvements in traditionally constructed buildings.

In order to achieve the CO2 reduction targets set by the Scottish government, it will be necessary to improve the energy efficiency of existing buildings. Within the total Scottish building stock, historic and traditionally constructed buildings are an important proportion, in the order of 19 % (Curtis, 2010), and represent cultural, emotional and identity values that should be protected. However, retrofit interventions could be a complex operation because of the several aspects that are involved in the hygrothermal performance of traditional buildings. Moreover, all these factors interact with each other and therefore need to be analysed as a whole. Upgrading the envelope of traditional buildings may produce severe changes to the moisture migration leading to superficial or interstitial condensation and thus fabric decay and mould growth. Retrofit projects carried out in the past have failed because of the misunderstanding, or the lack of expert prediction, of the potential consequences associated to the envelope's alteration. The evaluation of potential risks, prior to any alteration on building's physics in order to improve its energy efficiency, is critical to avoid future damage on the wall's performance or occupants' health and well being. The aim of this PhD research project is to point out the most critical aspects related to the energy efficiency improvement of traditional buildings and to develop a risk based methodology that helps owners and practitioners during the decision making process