Patrones de variación isotópica y reconstrucción de la dieta

According to Lockwood (2006, p.130) the influential factors causing a shift in thinking towards green buildings (GB) are threefold, namely: 1) the creation of reliable building-rating and certification systems for new construction and renovations⁵⁶; 2) in the international context, recent studies have proven the financial advantages for tenants of going green⁵⁷; and 3) GB materials, mechanical systems, and furnishing have become widely available, and their prices have dropped considerably – in some cases below the cost of their standard counterparts⁵⁸.

Green Buildings Definitions in the Relevant Literature

According to Nelson et al. (2010), green, sustainable, and low-energy buildings are just some of the definitions available in the specialized literature for concepts that are "green"

in the broadest sense and, therefore, the authors argued that further classification of the existing concepts is needed. Moreover, the authors stated that the diversity of terms in

56For example, in 2000 the U.S. Green Building Council (USGBC) launched its rigorous Leadership in Energy and Environmental Design (LEED) rating program. The program is reviewed in detail, amongst other GB certification systems, in the following sections.

57 Well designed green buildings have lower utility costs, it was argued; for example, in its first year of operation, the LEED-certified Genzyme Center used 42% less energy and 34% less water that standard buildings of comparable size (Lockwood 2006, p.130)

58 According to Turner Construction, four industry studies of more than 150 sustainable buildings across the U.S. show that, on average, it cost only 0.8% more to achieve basic LEED certification than to construct a standard building.

the relevant literature are used to define green buildings⁵⁹ which exhibit more and better features than standard buildings, built to the local building regulations defined in the building codes.

An analysis and a comparison of the range of existing concepts to define what "green"

buildings are it is provided in the work of Lützkendorf (2009). According to the author, the range of concepts goes from low-energy buildings, which only consider energy efficiency, to sustainable buildings, which cover all aspects listed in Table 12.

Table 12: Green Building Definitions and Main Components (Source: Own compilation based Lützkendorf 2009)

As shown in table above, energy efficiency is one of the cross-cutting issues to the whole range of GB definitions; other aspects are resource intensity and health. In contrast, the concept of “sustainable buildings” is the only concept that covers all desirable aspects for achieving a GB. Therefore, from this perspective it is valid to argue that achieving energy efficiency in buildings is a step – probably the first and most important one – towards achieving sustainability in building construction; situation discussed further in the conclusions of this doctoral thesis.

59 According to McCartney (2007) and Nelson (2008) (cited on Nelson et al. 2010, pp. 3–4), the main Features of GB include: 1) Efficient use of natural resources; 2) Waste minimization; 3) Eco-friendly construction materials, 4) Incorporation of local climate conditions; 5) Less energy required to transport building materials; 6) Limited impact on surroundings (e.g. lower emissions, noise, smell); 7) Consideration of life cycle costs; 8) Health; 9) Location near population centres and close to public transportation facilities;

10) Efficient building management and commissioning; 11) Social capacity and building user’s comfort; 12) Convenient indoor environment.

Benefits of Green Buildings

Beyond the still open debate about the different concepts and features of GB, the relevant literature seems to agree in a variety of benefits for designers, developers, builders, homeowners, and householders that might be achieved through the implementation of green design. These benefits can be direct or indirect.

According to Kats et al. (2003), the direct benefits of green buildings are much greater than the costs throughout the life cycle of the building. According to the authors, the cost of obtaining platinum and silver LEED-certified buildings are respectively 2% and 6.5%

higher than a normal building, respectively. However, LEED-certified buildings reduce their energy consumption on average by 30%, not to mention the benefits associated with water use, reduced CO₂ emissions, and reduced maintenance costs.

Moreover, according to Edwards (2003) indirect benefits generated by the GB for private developers, owners, and tenants are threefold. 1) GB are healthier to use; mainly because natural climate conditioning techniques are used (mainly lighting and ventilation) and organic materials are preferably used for building construction. 2) GB provide a psychological advantage; this advantage is mainly related to the use of internal spaces of buildings, since a major effort in the implementation of green space is made, creating a sense of wellbeing indoors. 3) GB enhance the corporate image; since the decision to implement green design strategies among the building design represents the involvement and a close relationship between a design team of specialists and client; the mere decision to opt for such effort is already reflected in the image of the company that implements green design.

Factors Influencing a Broader Adoption of Green Buildings

The preceding section stresses the ongoing discussion in the relevant literature regarding the variety of benefits – direct and indirect – that the so-called GB may generate for developers, homeowners, and tenants. However, the literature also emphasizes that, compared with other sectors of society and the business world, the real estate sector has been relatively slow in embracing green initiatives (Nelson et al. 2010).

The work of Nelson et al. (2010) identifies a group of four main factors influencing the slow adoption of green initiatives specifically in the housing market. First, it is argued that at the beginning of the so-called "green movement", the lack of awareness among

investors and the lack of experience among real estate developers were the most important factors to slow the process of innovation in GB. Second, it was mentioned that the lack of transparent and reliable data, regarding the real estate market, has limited the demonstration and reliable comparison of the financial behaviour of GB against conventional buildings, especially in the European context. Third, A misalignment between costs and benefits for tenants and owners – according to economists, the so-called "agency problem" – it was mentioned as a relevant preventing factor for owners and investors to decide for green strategies; mainly because for them, applying such strategies means making a higher initial expenditure whilst the benefits will be perceived by tenants or other end users of buildings. And fourth, the difference in the investment horizon for GB and conventional buildings; it was argued that homeowners usually consider the only initial construction costs, while they should considered the investment over the entire life of the property – the so-called "life cycle costing" – although the GB have a slightly higher initial cost than in conventional buildings, they are usually less expensive to maintain and to operate, which eventually makes that – in the long run - the total cost of the property is actually lower.