Selecting Insulating Materials for Building Envelope: A Life Cycle Approach

Abstract

This paper aims at assessing the embodied energy and greenhouse gas emissions (GHGs) of two building envelopes, designed for a two floors semi-detached house located in the Central Italy. The analysis is performed by applying the Life Cycle Assessment methodology, following a from cradle-to-gate approach. Fixtures (windows and doors), external and internal opaque walls, roof and floors (including interstorey floors) make the building envelopes. Their stratigraphy allows for achieving the thermal transmittance values established in the Italian Decree on energy performance of buildings. The two examined envelopes differ only for the insulation material: extruded expanded polystyrene (XPS) or cellulose fibers. The results shows that the envelope using cellulose fibers has better performance than that using XPS: it allows for reducing the embodied energy and the GHGs of about 13% and 9.3%, respectively. A dominance analysis allows to identify the envelope components responsible of the higher impacts and the contribution of the insulating material to the impacts. The study is part of the Italian research “Analysis of the energy impacts and greenhouse gas emissions of technologies and components for the energy efficiency of buildings from a life cycle perspective” funded by the Three-year Research Plan within the National Electricity System 2019-2021.

Multi-Objective Techno-Economic Optimization of Design Parameters for Residential Buildings in Different Climate Zones

“…The internal walls (200 m 2 ) and floor area of second story (70 m 2 ) were added in the TRNBuild tool to include the internal capacities of the building structure. The thermal properties of the envelope were defined based on the local building energy standards of each investigated location [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]. These standards provide the limits of thermal transmittance (U-value) for different components of the envelope.…”

“…In most regions, building energy standards are established but contain limited information on building envelope components. Usually, those standards provide the allowable thermal resistance or transmittance of the envelope components and WWR in some cases [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]. The comprehensive design approach involves building performance simulations, which are time-consuming and require knowledge of complicated processes.…”