Design Strategies and LCA of Alternative Solutions …
209
chipboard and wood composites is very active, not only in the construction supply
chain but also in the furniture supply chain, end-of-life recycling of structural wood
is a plausible hypothesis. The project was therefore designed with a predominantly
wooden structure, with pillars and floors in X-lam, in line with the design choices
aimed at constructive reversibility and the potential reusability or recyclability of the
entire construction (circular building).
From the point of view of system choices, to have an advantage in terms of carbon
footprint, the choice must necessarily fall on the use of photovoltaic which can
produce free energy from the sun. In this case, attention must be placed on effective
positioning of the panels with respect to solar exposure so that the production of
energy during use compensates for the production impact of the panel and allows for
CO 2 gains in terms of avoided impacts compared to the use of other sources.
In the later phases of the project, the contribution of environmental consultancy
to project choices focused on more detailed aspects, trying to optimize the carbon
footprint of the other parts of the building. The call requires a low-carbon building,
compared to a “business as usual” (BAU) building. Consequently, the work setup was
based on a comparison among technical solutions and design choices, demonstrating
through LCA evaluation the “environmental gains” obtained from the project choices
with respect to choices typically implemented in current practice.
The “background” data (EC-JRC 2012), related to the environmental LCI and
LCA of building products, were derived from the Environmental Product Declaration (EN 15804:2012) and, only when the EPDs were not available for the specific
component, from databases (Ecoinvent, Ökobaudat, Inventory of Carbon and Energy
ICE). The choice to use primary data deriving from EPD is linked to the desire to
identify low impact products not only by comparing alternative materials but also by
selecting products with the lowest environmental impact within the same material
compartment. The materials selected have a lower carbon footprint for their recycled
content, their production process based on the principles of a circular economy (e.g.,
industrial ecology) or their plant matrix content (absorbers of CO 2 during the growth
of the plant). Transportation was also taken into consideration: for example, in the
case of the concrete that constitutes the foundations, a more distant producer was
chosen, but which guarantees a concrete with a lower environmental impact in the
production process.
After the collection of CO 2 data related to alternative solutions, the assessment
considered the highest and lowest values of CO 2 eq emissions related to the phases
A1–A4 (A1—raw materials supply, A2—transport to the production plant, A3—
production, and A4—transport to the building site). For each part of the building
considered, a comparison was made among possible materials and alternative producers, selecting the product with the lowest emissions (l.e.) and the product with
the highest emissions (h.e.) among those (with EPD) present on the market; therefore, the material with the lowest emissions was selected (if compatible with the
high-performance levels required by the project target). The database values were
considered as a reference for the average values or assumed as comparison values
only for materials without an EPD (Figs. 1 and 2).
209
chipboard and wood composites is very active, not only in the construction supply
chain but also in the furniture supply chain, end-of-life recycling of structural wood
is a plausible hypothesis. The project was therefore designed with a predominantly
wooden structure, with pillars and floors in X-lam, in line with the design choices
aimed at constructive reversibility and the potential reusability or recyclability of the
entire construction (circular building).
From the point of view of system choices, to have an advantage in terms of carbon
footprint, the choice must necessarily fall on the use of photovoltaic which can
produce free energy from the sun. In this case, attention must be placed on effective
positioning of the panels with respect to solar exposure so that the production of
energy during use compensates for the production impact of the panel and allows for
CO 2 gains in terms of avoided impacts compared to the use of other sources.
In the later phases of the project, the contribution of environmental consultancy
to project choices focused on more detailed aspects, trying to optimize the carbon
footprint of the other parts of the building. The call requires a low-carbon building,
compared to a “business as usual” (BAU) building. Consequently, the work setup was
based on a comparison among technical solutions and design choices, demonstrating
through LCA evaluation the “environmental gains” obtained from the project choices
with respect to choices typically implemented in current practice.
The “background” data (EC-JRC 2012), related to the environmental LCI and
LCA of building products, were derived from the Environmental Product Declaration (EN 15804:2012) and, only when the EPDs were not available for the specific
component, from databases (Ecoinvent, Ökobaudat, Inventory of Carbon and Energy
ICE). The choice to use primary data deriving from EPD is linked to the desire to
identify low impact products not only by comparing alternative materials but also by
selecting products with the lowest environmental impact within the same material
compartment. The materials selected have a lower carbon footprint for their recycled
content, their production process based on the principles of a circular economy (e.g.,
industrial ecology) or their plant matrix content (absorbers of CO 2 during the growth
of the plant). Transportation was also taken into consideration: for example, in the
case of the concrete that constitutes the foundations, a more distant producer was
chosen, but which guarantees a concrete with a lower environmental impact in the
production process.
After the collection of CO 2 data related to alternative solutions, the assessment
considered the highest and lowest values of CO 2 eq emissions related to the phases
A1–A4 (A1—raw materials supply, A2—transport to the production plant, A3—
production, and A4—transport to the building site). For each part of the building
considered, a comparison was made among possible materials and alternative producers, selecting the product with the lowest emissions (l.e.) and the product with
the highest emissions (h.e.) among those (with EPD) present on the market; therefore, the material with the lowest emissions was selected (if compatible with the
high-performance levels required by the project target). The database values were
considered as a reference for the average values or assumed as comparison values
only for materials without an EPD (Figs. 1 and 2).