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The changes and challenges of LEED V4

Sustainability 作者 Jose Castilla, Director, Sustainability – 19 十一月 2014

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Jose Castilla

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By Jose Castilla

After having the opportunity to work in both LEED N2.2 and LEED 2009 BD&C versions, I see that the new LEED V4 will challenge the building industry quite substantially. For countries such as Spain where the sustainability agenda is still somehow behind, the new version of LEED may have the greatest impact in the last 10 years.

Although the scoring has been maintained, the credit categories have been rearranged in a different way. In addition the LEED tool is now able to be used more specifically in different building schemes (i.e. data centres, hospitality, logistics centres) as opposed to a one-way route only that was to be followed in LEED 2009 for most of the non-residential projects. This new compliance paths will give teams the tools to apply sustainability criteria in a more sound way. A clear example can be found in how the new tool deals with the energy consumption in a data centre facility; aspects such as PUE value, virtualisation, water consumption for adiabatic processes are now properly addressed.

Running from the top to bottom on the different categories, the following highlights some of the main changes:

  • Integrative process – teams are encouraged to start their inputs earlier in the process. A good concept design is key to delivering a robust sustainable design. For that reason, points are available for projects that engage multidisciplinary teams right at the start to analyse orientation, energy, comfort, daylight in a more holistic approach.
  • Public transport access and access to local amenities – this is now a must. Previous LEED tools were less stringent in relation to how the public transport was arranged around the building. With the new version, the location must be such that a good number of transport rides are guaranteed. This tougher requirements matches with urban locations leaving more remote areas with less possibility of scoring high. Access to public amenities and within a densely populated area are now combined and required to get the most of this categories.
  • Water conservation – This category will require certain degree of market evolution as a new labelling requirement is introduced (water sense). This will have the same impact as energy star labelling had in the electronic equipment some years ago. Additionally, there is a new pre-requisite that considers water-friendly landscape design. The domestic hot water reduction required to comply with the pre-requisite will now be calculated without considering the recycled water contribution making the design more stringent. This will have a greater impact in the whole water cycle. Process water consideration is also a massive change. Cooling towers and adiabatic coolers are now required to recycle its water. Flush out will also be reduced and more water treatment and control will be considered.
  • Energy consumption requirements are strengthened - design would have to be in the order of 20% more efficient if compared with previous versions, as it now follows ASHRAE 90.1-2010. Lighting design will be smarter with greater automation and user’s control. Renewable energy requirements has been relaxed at the expense of increasing the design requirements. This follow a good logic of reducing demand and consumption before making efforts in renewable energy production. Smart grid-friendly design are now encouraged with the view of merging closer, with demand and energy production. Finally, building commissioning will also face a huge change with earlier involvement in the design process with more systems under their scope. A new requirement for envelope commissioning has been introduced involving thermal imaging analysis and blow tests.
  • Material selection – this will require the market to incorporate more standardised procedures and labelling. Similarly to what we saw with the FSC accreditation, other materials will follow by declaring its recycling content, its row materials or the life cycle, amongst other indicators. The design may incorporate a life cycle assessment for projects where recycling the structure or the interior components are not a possibility.
  • Indoor environmental quality - the biggest change in my opinion has to do with the daylight access analysis. A climate based approach has now been incorporated as an alternative to the traditional daylight factor analysis. Daylight factor often oversized the glazing area in order to achieve the required daylighting access. This was inappropriate, especially in warmer climates where it would lead to excessive glare and solar gain, resulting in thermal discomfort resulting in excessive internal blind usage with the resultant increase in electricity consumption both for lighting and for cooling the additional loads. A climate based analysis now consider solar intensity as well as cloud coverage and orientation for every hour of the year and represents more accurately the expected behaviour of the internal occupants.

As any regulatory change, the industry (from clients to consultants or manufacturers) needs time to adapt and absorb the new rules of play. The new LEED tool has evolved and it is now less likely that the LEED process becomes a tick box exercise. Real efforts need to be put in place for scoring high. Up to October 2016, the previous version is available together with the new tool. There is still plenty of time for everyone to get ready but you should start moving now.

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