Z E M C H 2 0 1 2 I n t e r n a t i o n a l C o n f e r e n c e
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Hence, on the roofing system we applied the following LEED versions:
o
LEED Italia 2009
, which is the USGBC recognized adaptation of the American
LEED NC for Italy,
o
LEED v.4
-
Building Design & Construction
(
2nd Public Comment Draft, July
2011),
which will be launched in 2013 in USA and also applicable outside from
North America.
For each credit category we:
_ selected prerequisites and credits for which the current stratigraphy of the roofing
system is able to give a contribution;
_ analyzed and compared prerequisites and credits mentioned above, with a
comparative matrix, in which the maximum contribution achievable together with
materials and products of the whole building was calculated;
_ found credits not achievable with the current composition of the roof, but reachable by
choosing functionally equivalent LEED compliant materials and products.
On the contrary, LCA has been chosen because it is one of the emerging BSA (Building
Sustainability Assessment) tools inside the scientific community and there is much
research on this topic all over the world.
It is only based on the use of objective and measureable indicators, that allow designing
by using a performance approach and not a prescriptive one, giving to designers the
possibility to implement non-standardized sustainability strategies.
For performing the LCA analysis of the roof the database
EcoInvent
(CH) was used, in
which the impacts associated to different materials are calculated on the European
average values.
The chosen calculation method for the research work is the
EPD method
, used for
realizing environmental product declarations. The choice to use this method is mainly
caused to the possibility to integrate in the calculation process materials with EPD
certificate, by using a common set of quantitative parameters:
o
Global Warming Potential (GWP)
o
Ozone Depletion Potential (ODP)
o
Acidification Potential (AP)
o
Eutrophication Potential (EP)
o
Photochemical Ozone Creation Potential (POCP)
o
non-renewable Primary Energy Use (PEnr).
LEED Italia 2009 vs. US LEED v.4
The differences between LEED Italia and the LEED v.4 are limited to three main areas:
o
new credit categories
: Integrative Process (IP), Location and Transportation (LT),
Performance (PF) that help teams understand how to best achieve their project
priorities;
o
changes to technical content
that increases the technical rigor of the rating
system;
o
revised point distribution
that will more closely tie the rating system requirements
to the priorities articulated by the USGBC community.
From the comparative analysis of LEED credit categories, the following remarks
emerged. New prerequites have been introduced; credits still have different compliance
paths, but each of them is articulated in more cases, depending on the type of project.
Nevertheless the introduction into LEED of these new credits, it will continue to have 100
base points and four certification levels:
certified, silver, gold
and
platinum.
The graph below underlines the point distribution into the different credit categories of
LEED Italia 2009 and US LEED v.4 (Fig.3).
