A Stochastic Approach to LCA of Internal Insulation Solutions for Historic Buildings

Elisa Di Giuseppe,Guangli Du,Claudio Favi,Gianluca Maracchini,Marco D’Orazio,Pierryves Padey,Sébastien Lasvaux

doi:10.3390/su12041535

Abstract

Internal insulation is a typical renovation solution in historic buildings with valuable façades. However, it entails moisture-related risks, which affect the durability and life-cycle environmental performance. In this context, the EU project RIBuild developed a risk assessment method for both hygrothermal and life-cycle performance of internal insulation, to support decision-making. This paper presents the stochastic Life Cycle Assessment method developed, which couples the LCA model to a Monte-Carlo simulation, providing results expressed by probability distributions. It is applied to five insulation solutions, considering different uncertain input parameters and building heating scenarios. In addition, the influence of data variability and quality on the result is analyzed, by using input data from two sources: distributions derived from a generic Life Cycle Inventory database and “deterministic” data from Environmental Product Declarations. The outcomes highlight remarkable differences between the two datasets that lead to substantial variations on the systems performance ranking at the production stage. Looking at the life-cycle impact, the general trend of the output distributions is quite similar among simulation groups and insulation systems. Hence, while a ranking of the solutions based on a “deterministic” approach provides misleading information, the stochastic approach provides more realistic results in the context of decision-making.

Highlights

The building sector is the single largest energy consumer and responsible for approximately 42% of energy consumption, 35% to 40% of CO2 emissions, 20% of all waste and 40% of all materials used in Europe [1]
It is worth noting that the declared unit in the Environmental Product Declarations (EPDs) has been scaled to 1 kg for each construction product to allow the comparison with the ecoinvent database
Concerning the Cumulative Distribution Functions (CDF), as expected, a low scattering has been obtained for the simulation group 1 (EPDs data) (Figure 4a), with geometric coefficient of variation (gCV) of about 2% to 3%, excepting for the RW case

Summary

Introduction

The building sector is the single largest energy consumer and responsible for approximately 42% of energy consumption, 35% to 40% of CO2 emissions, 20% of all waste and 40% of all materials used in Europe [1]. It is estimated that almost 75% of the building stock is energy inefficient, while only 0.4% to 1.2% of it is renovated each year [2]. The thermal insulation of such inefficient building is a necessary step to meet the European energy efficiency objectives. In the case of historic buildings, external thermal insulation is often not suitable due to the need of preserving the facades along with their aesthetical, heritage, and cultural values. For this reason, internal insulation is generally considered as a valid alternative to external insulation in order to improve the buildings’ thermal performance. The EU project RIBuild (Robust Internal Thermal Insulation of Historic Buildings) aims to fill this gap, by investigating how and under which conditions internal insulation can be safely used [6]

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