Energy Retrofitting of a Buildings’ Envelope: Assessment of the Environmental, Economic and Energy (3E) Performance of a Cork-Based Thermal Insulating Rendering Mortar

Abstract

This paper presents an environmental, economic and energy (3E) assessment of an energy retrofitting of the external walls of a flat of an average building with the most current characteristics used in Portugal. For this intervention, a cork-based (as recycled lightweight aggregate) TIRM (Thermal Insulating Rendering Mortar) was considered. The declared unit was 1 m2 of an external wall for a 50-year study period and the energy and economic costs and savings, as well as the environmental impacts, were analytically modelled and compared for two main alternatives: the reference wall without any intervention and the energetically rehabilitated solution with the application of TIRM. Walls with improved energy performance (with TIRM) show lower economic and environmental impacts: reductions from 6% to 32% in carbon emissions, non-renewable energy consumption and costs during the use stage, which depends on the thickness and relative place where TIRM layers are applied. A worse energy performance is shown by reference walls (without TIRM) during the use stage (corresponding to energy used for heating and cooling), while the improved walls present economic and environmental impacts due to the application of TIRM (including the production, transport and application into the building) that do not exist in the reference walls. The comparison between reference walls and energy-retrofitted ones revealed that reference wall become be more expensive when more demanding operational energy requirements are analysed over a 50-year period, even if renewable materials are more expensive.

Avaliação Da Contribuição Dos Insumos No Impacto Ambiental Da Argamassa De Revestimento

“…No intuito de avaliar a representatividade de cada insumo e de cada categoria de impacto, conforme já explicado, os dados foram normalizados. Analisando os resultados notou-se que ao contrário do que se esperava com base na revisão da literatura (7,10,11,12,13,14,15,16,17) , a categoria de Aquecimento Global não foi a mais representativa. Ressalta-se que o conjunto de normalização da CML baseline é do ano de 2000, por isso, é preciso considerar que em anos diferentes as emissões podem ser consideravelmente divergentes em virtude das atividades humanas e densidade demográfica do ano tomado como referência.…”

Special Issue “Building Thermal Envelope”

“…Another study was developed by Silvestre et al [3] on the environmental, economic and energy (3E) assessment of external wall energy retrofitting with a cork-based (as recycled lightweight aggregate) thermal insulating rendering mortar (TIRM). The case study was a flat roof of an average building with the most current characteristics used in Portugal.…”

Integrated Performance Evaluation of Aerogel-Based Fibre-Enhanced Thermal Renders Applied on Building Walls

“…Although some integrated approaches already exist regarding the environmental, energy and economic savings of thermal insulation [31][32][33], the most common method of selection and determination of the optimum thicknesses is based on degree-day heat loss analysis [34]. This method considers the initial cost of the thermal insulation material and the energy savings throughout the entire service life, allowing for the determination of the optimum insulation thickness that corresponds to the minimum service life cost [35].…”

“…A thorough study of the aerogel-based thermal renders was performed [30] regarding the anticipatory modelling [57,58]. However, the material potential for environmental, energy and economic savings in buildings [12,32] still has to be quantified, pointing to a lack of knowledge on comprehensive and quantified data regarding an integrated approach which includes comparisons with other existing thermal insulators.…”