| Preservation of energy resources, occupant comfort and environmental impact limitation are the key issues of modern and sustainable architecture. A multiple-view assessment of building performance at the design stage is therefore essential in order to prevent the delivery of buildings that do not comply with modern constraints. For more than a quarter of a century, building simulation programs have been developed to support non-trivial performance appraisals. In general, these programs deal with a small sub-set of the overall problem. To obtain a global view, solutions that permit stand-alone programs to inter-operate by sharing and exchanging common sets of information have therefore been developed. However, these solutions do not support dynamic information exchange and their complicated data management may lead to result inconsistency. Even if computer technology has rapidly evolved during the last few decades, no satisfactory level of integrated building representation has therefore been achieved so far, neither horizontally between different views nor vertically between all the processes that occur during the p roject life span.
This dissertation proposes a different approach that incorporates different views within a single program. The efforts undertaken in this work focused on (1) the design of the building data model, (2) its implementation into a single application and (3) its application to a case study to assess the building performance (thermal, lighting, acoustics, etc.) as well as occupant comfort and the environmental impacts generated by the building during its whole life span. Please note that cost estimation, construction planning or more subjective views, such as aesthetics, have not been considered in th is work.
Chapter 1 points out the importance of using multiple-views during building design. It also gives the description of some constructive solutions developed in the past, which concurrently fulfil several assignments. It also illustrates the consequences of a lack of multiple-view assessment in appraising the building performanc e in modern architecture.
Chapter 2 reports different potential approaches to a multiple-view assessment of building performance. Although experimental methods are useful in various situations, the requirements of a holistic approach are better met by mathematical methods, especially computer simulation. This chapter scrutinises the approaches developed in computer simulation to provide a multipleview assessment. Finally, this chapter analyses the capabilities of available integrated simulation programs, which leads to the conclusion that none of the available simulation applications can concurrently perform the assessment of the building performance (thermal, lighting, ventilation, acoustics), the occupant comfort and the environmental impacts over the whole life cycle of the building. Chapter 3 focuses on the requirements of a digital representation of the building that enables a comprehensive representation of building elements with sufficient information to support a multiple-view assessment. It reviews the building representation developed since the 70's, especially the capability of two approaches to standardise the building representation. Scrutiny of the ava ilable approaches leads to the conclusion, that even though considerable efforts have been
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undertaken, no standardised model that meets the requirements of a building representation that
can support a holistic appraisal has yet been developed.
An important issue of this chapter is to define the assignments of the building representation,
which supports view variations throughout the building life cycle in relation to performance
views such as energy consumption, occupant comfort, room acoustics and the environmental
impacts related to the construction materials and fuel streams over the whole building life span.
This could be achieved thanks to the decoupling of the geometrical representation of the building
and the description of the construction materialisation. This latter is structured by view, that are:
hygro-thermal, optical, photo-colourimetry, room acoustics and environmental impacts. For each
particular view, the physical attributes encompass a comprehensive set of attributes to become
assessment methods independent. Finally, to support a detailed life cycle impact assessment, the
environmental attributes are structured around a life cycle phase decomposition of the building
life span.
The proposed approach could be implemented in the form of a new integrated application that
enables a holistic assessment of building performance. However, within the time schedule of this
work, it would not have been feasible to develop a new application starting from scratch. It was
therefore preferred to select an existing building simulation program in which the proposed data
model was then implemented, which is presented in Chapter 4. As a result of the selection
procedure, ESP-r, a transient energy simulation system, which is capable of modelling energy
and fluid flows within combined building and plant systems, was chosen. This chapter details the
data model by view and ends with its technical implementation within the selected application.
To support the holistic approach advocated in this document, the original functions of ESP-r
have been extended to support the assessment of the missing views, which is the scope of the
following two chapters.
Chapter 5 presents the methodology developed to assess in detail the environmental impact
generated by a building during its entire life span. To take account of all impacts, a global
balance of the materials and energy flows required during the building life has to be established.
The presented methodology focuses not only on the impacts related to material manufacturing,
but also on those of transport, assembly, maintenance, replacement and final disposal at the end
of the building life. The proposed model meets the requirements of the life cycle assessment
framework proposed by the International Organisation for Standardisation (ISO) for the
assessment of the environmental impacts of a product.
Chapter 6 presents a second extension of the ESP-r capabilities, which enables the assessment of
the room acoustics. The reverberation time is selected as an indicator to assess the room
performance and is appraised with three different formulations of the diffuse-sound field theory,
that are the Sabine, Eyring and Millington equations. The calculation includes the absorption of
the enclosure boundaries, the occupants and furniture, and the enclosed air. The air temperature
and humidity are also taken into account to improve the calculation of the sound speed and the
air absorption.
Chapters 5 and 6 only present the methods used to assess the life cycle impact assessment and
the room acoustics, but do not evaluate the conformance of the results obtained. This is done in
Chapter 7, where a building case study is selected to demonstrate the applicability of the
proposed approach. It presents the overall performance obtained for an office building as
predicted by ESP-r enhanced with the development undertaken in this dissertation. The
simulation results are compared with measurements monitored in the building during the post-
occupancy phase. This chapter does not have the pretension to validate the simulation, but rather
to analyse the conformity of the simulation results with in-situ measurements.
The document is structured in master chapters, which rapidly focus on the specificity developed
in this work. To catch this dissertation globally, the reader requires particular knowledge in
several domains. For the person who is not familiar with one of the tackled domains, specific
vocabulary and concepts are summarised in appendixes. | 
