R o o f i n g S y s t e m S u s t a i n a b i l i t y
603
The structure of the roof is in glulam beams with a plywood desk and cross-laminated
timber panels (X-LAM) for the overhangs. The insulation is composed of two layers of
wood fiber: the first one is a rigid wood fiber board of 80 mm, put directly on the plywood
and the second one is a flexible wood fiber board of 160 mm located into the beams
wheelbase.
Upon the high-density insulation a breathable waterproof barrier is. Laths with a section
of 80x120 mm realize a gap for roof ventilation and technical plants installation; upon this
gap a wood planking of 28 mm is. On this planking there is a breathable and acoustic
waterproof barrier. The external covering is in crimped titanium-zinc sheet.
The internal finishing is realized with plasterboard, put under a vapor brake, between the
beams.
Research objectives
Actually, the major part of RSs does not take into account LCA methodology, but it is
based on more general and qualitative evaluation, such as: recycled content and
recyclability, local production, renewability of raw materials, use of non pollutant products
and presence of certified wood, forgetting the importance of LCA from a sustainability
perspective.
Recently the tendency to integrate LCA into RSs for implementing the issues related to
the building materials has emerged. For example the main RSs including such kind of
criteria are:
o
DGNB
(Deutsche Gesellschaft für Nachhaltiges Bauen)
o
BREEAM
(BRE Environmental Assessment Method)
o
LEED v.4
(Leadership in Energy and Environmental Design)
.
The
Laboratory of Building Design of the University of Trento
has been carrying out
research on RSs structure and LCA application in the building sector. The work is now
oriented to understand the importance of integrating LCA into RSs.
The neighbourhood
“Le Albere”
in Trento has been selected as case study in order to
verify the research method. Due to the high complexity of this area and of RSs, we
decided to focus the attention on analysing a building sub-assembly, rather than the
whole building. Only after the methodology validation, the study will be extended to the
entire construction.
This approach will allow to designers/manufacturers to assess and measure not only the
sustainability of the existing sub-assemblies, but also to get inputs for improving its
sustainability and energy efficiency features.
Research methodology: integrated application of RSs and LCA
The research work is based on the comparative application of LEED systems and LCA
analysis on the
roofing sub-assembly of “Le Albere” neighborhood
.
LEED was chosen as reference RS for many reasons. First of all, LEED is one of the
most widespread international RSs and it is currently used also for the certification of
some buildings in the case study area, because in Trentino region LEED is the
mandatory standard for all public buildings, although it is a voluntary-based system.
The USGBC community has been developing a new version of LEED, in which the
technical rigor will be increased. This new version is life-cycle-based and has some
criteria in which the use of LCA is included. This allows us to analyze and compare the
system with and without LCA.
