Editing IPCC:AR6/WGIII/Chapter-9 (section)

== 9.2 Services and Components ==

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This section mainly details the boundaries of the building sector; mitigation potentials are evaluated in the following sections.

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=== 9.2.1 Building Types ===

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Building types and their composition affect the energy consumption for building operation as well as the GHG emissions ( [[#Hachem-Vermette--2019|Hachem-Vermette and Singh 2019]] ). They also influence the energy cost ( [[#MacNaughton--2015|MacNaughton et al. 2015]] ) therefore, an identification of building type is required to understand the heterogeneity of this sector. Buildings are classified as residential and non-residential buildings. Residential buildings can be classified as slums, single-family house and multi-family house or apartment/flats building. Single-family house can be divided between single-family detached (including cottages, house barns, etc.) and single-family attached (or terrace house, small multi-family, etc.). Another classification is per ownership: owner-occupiers, landlords, and owners’ association/condominiums.

Non-residential buildings have a much broader use. They include cultural buildings (which include theatres and performance, museums and exhibits, libraries, and cultural centres), educational buildings (kindergarten, schools, higher education, research centre, and laboratories), sports (recreation and training, and stadiums), healthcare buildings (health, well-being, and veterinary), hospitality (hotel, casino, lodging, nightlife buildings, and restaurants and bars), commercial buildings and offices (institutional buildings, markets, office buildings, retail, and shopping centres), public buildings (government buildings, security, and military buildings), religious buildings (including worship and burial buildings), and industrial buildings (factories, energy plants, warehouses, data centres, transportation buildings, and agricultural buildings).

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=== 9.2.2 Building Components and Construction Methods ===

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An understanding of the methods for assembling various materials, elements, and components is necessary during both the design and the construction phase of a building. A building can be broadly divided into parts: the substructure which is the underlying structure forming the foundation of a building, and the superstructure, which is the vertical extension of a building above the foundation.

There is not a global classification for the building components. Nevertheless, Figure 9.1 tries to summarise the building components found in literature ( [[#Mañá%20Reixach--2000|Mañá Reixach 2000]] ; [[#Asbjørn--2009|Asbjørn 2009]] ; [[#Ching--2014|Ching 2014]] ). The buildings are divided in the substructure and the superstructure. The substructure is the foundation of the building, where the footing, basement, and plinth are found. The superstructure integrates the primary elements (heavyweight walls, columns, floors and ceilings, roofs, sills and lintels, and stairs), the supplementary components (lightweight walls and curtain walls), the completion components (doors and windows), the finishing work (plastering and painting), and the buildings services (detailed in [[#9.3|Section 9.3]] ).

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[[File:d98f1eea1726750eb4edc5a3ef8b40b7 IPCC_AR6_WGIII_Figure_9_1.png]]

'''Figure 9.1 | The main building components.'''

At a global level, from historical perspective (from the Neolithic to the present), building techniques have evolved to be able to solve increasingly complex problems. Vernacular architecture has evolved over many years to address problems inherent in housing. Through a process of trial and error, populations have found ways to cope with the extremes of the weather. The industrial revolution was the single most important development in human history over the past three centuries. Previously, building materials were restricted to a few manmade materials (lime mortar and concrete) along with those available in nature as timber and stone. Metals were not available in sufficient quantity or consistent quality to be used as anything more than ornamentation. The structure was limited by the capabilities of natural materials; this construction method is called on-site construction which all the work is done sequentially at the buildings site. The Industrial Revolution changed this situation dramatically, new building materials emerged (cast-iron, glass structures, steel-reinforced concrete, steel). Iron, steel and concrete were the most important materials of the nineteenth century ( [[#Wright--2000|Wright 2000]] ; [[#De%20Villanueva%20Domínguez--2005|De Villanueva Domínguez 2005]] ). In that context, prefabricated buildings (prefabrication also known as pre-assembly or modularisation) appeared within the so-called off-site construction. Prefabrication has come to mean a method of construction whereby building elements and materials, ranging in size from a single component to a complete building, are manufactured at a distance from the final building location. Prefabricated buildings have been developed rapidly since the Second World War and are widely used all over the world ( [[#Pons--2014|Pons 2014]] ; [[#Moradibistouni--2018|Moradibistouni et al. 2018]] ).

Recently, advances in technology have produced new expectations in terms of design possibilities. In that context, 3D printing seems to have arrived. 3D printing may allow in the future to build faster, cheaper and more sustainable ( [[#Agustí-Juan--2017|Agustí-Juan et al. 2017]] ; [[#García%20de%20Soto--2018|García de Soto et al. 2018]] ). At the same time, it might introduce new aesthetics, new materials, and complex shapes that will be printed at the click of a mouse on our computers. Although 3D printing will not replace architectural construction, it would allow optimisation of various production and assembly processes by introducing new sustainable construction processes and tools ( [[#De%20Schutter--2018|De Schutter et al. 2018]] ). Nevertheless, what is clear is that 3D printing is a technology still in development, with a lot of potentials and that it is advancing quite quickly ( [[#Hager--2016|Hager et al. 2016]] ; [[#Stute--2018|Stute et al. 2018]] ; [[#Wang--2020|Wang et al. 2020]] ).

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=== 9.2.3 Building Services ===

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Building services make buildings more comfortable, functional, efficient, and safe. In a generic point of view, building services include shelter, nutrition, sanitation, thermal, visual, and acoustic comfort, entertainment, communications, elevators, and illumination. In a more holistic view building services are classified as shown in Figure 9.2.

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[[File:224bc77a492041296f6b6f6f9e031e1e IPCC_AR6_WGIII_Figure_9_2.png]]

'''Figure 9.2 | Classification of building services.''' The coloured small squares to the left of each building service denote to which other classifications that building service may relate to a lesser extent. Source: adapted from [[#Vérez--2021|Vérez and Cabeza (2021)]] .

A building management system is a system of devices configured to control, monitor, and manage equipment in or around a building or building area and is meant to optimise building operations and reduce cost ( [[#Schuster--2019|Schuster et al. 2019]] ). Recent developments include the integration of the system with the renewable energy systems ( [[#Arnone--2016|Arnone et al. 2016]] ), most improved and effective user interface ( [[#Rabe--2018|Rabe et al. 2018]] ), control systems based on artificial intelligence and internet of things (IoT) ( [[#Farzaneh--2021|Farzaneh et al. 2021]] ).

The use of air conditioning systems in buildings will increase with the experienced rise in temperature ( [[#Davis--2015|Davis and Gertler 2015]] ; [[#De%20Falco--2016|De Falco et al. 2016]] ) (Figure 9.8). This can ultimately lead to high energy consumption rates. Therefore, adoption of energy efficient air conditioning is pertinent to balance the provision of comfortable indoor conditions and energy consumption. Some of the new developments that have been done include ice refrigeration ( [[#Xu--2017|Xu et al. 2017]] ), the use of solar photovoltaic power in the air conditioning process ( [[#Burnett--2014|Burnett et al. 2014]] ), and use of common thermal storage technologies ( [[#De%20Falco--2016|De Falco et al. 2016]] ) all of which are geared towards minimising energy consumption and greenhouse gas emissions.

Building designs have to consider provision of adequate ventilation. Natural ventilation reduces energy consumption in buildings in warm climates compared to air conditioning systems ( [[#Taleb--2015|Taleb 2015]] ; [[#Azmi--2017|Azmi et al. 2017]] ). Enhanced ventilation has higher benefits to the public health than the economic costs involved ( [[#MacNaughton--2015|MacNaughton et al. 2015]] ).

On the refrigeration systems, the recent developments include the use of solar thermoelectric cooling technologies as an energy efficient measure ( [[#Liu--2015b|Liu et al. 2015b]] ); use of nanoparticles for energy saving ( [[#Azmi--2017|Azmi et al. 2017]] ) to mention some.

[[#Lambertz--2019|Lambertz et al. (2019)]] stated that when evaluating the environmental impact of buildings, building services are only considered in a very simplified way. Moreover, it also highlights that the increasing use of new technologies such as Building Information Modelling (BIM) allows for a much more efficient and easier calculation process for building services, thus enabling the use of more robust and complete models. Furthermore, recent studies on building services related to climate change ( [[#Vérez--2021|Vérez and Cabeza 2021]] ) highlight the importance of embodied energy ( [[#Parkin--2019|Parkin et al. 2019]] ) ( [[#9.4|Section 9.4]] ).

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