Biodiversity burdens in Spanish conventional and low-impact single-family homes

Biodiversity loss caused by housing is not a well-defined sector of environmental impact. This research quantifies effects on biodiversity of an average Spanish Single-Family House (SFH) with 180 m2 of built surface. The current Spanish SFH stock GWP amounts to 1.16 Gt CO2eq in a 50-year life cycle, 40 % of which is embodied in the building materials and the 60 % are emissions due to the use of the building. This stock also impacts with 10.2 Gt 1,4-DCB the land, water and human health. SFHs also drive 6052 species extinct in a 50 year life cycle, and account for 3.03 M years of life lost due to premature death or lived with a disability. Divided by the 16 M people living in Spanish SFHs, each one lost 0.19 years of their lives (68.1 days) due to their home's impacts on human health. The article compares a reference conventional building against three low-impact cases, to understand how different building techniques and materials influence environmental outcomes that keep biodiversity loss the lowest possible. Scenarios include a standard brick and concrete house as Scenario 0 (SC0, Base), a timber Passivhaus as Scenario 1 (SC1), a straw-bale house with renewable energies as Scenario 2 (SC2), and an earth bioclimatic house as Scenario 3 (SC3). An initial Global Warming Potential (GWP) analysis was performed to relate previous building Life Cycle Assessment (LCA) studies with biodiversity metrics. Three main biodiversity metrics; ecotoxicity (as midpoint indicator), biodiversity loss and damage to human health (both as endpoint indicators) have been considered. Compared to SC0 with 1292 kgCO2-eq·m−2 (516 embodied) of GWP, we found that SC1 emitted −47.0 % of that, SC2–41.4 % and SC3–80.9 %. Concerning ecotoxicity, where SC0 has 11,399 kg 1,4 DCB, the results are −27.9 % in SC1, −19.2 % in SC2, and −45.6 % in SC3. Regarding biodiversity loss, where SC0 has 7.54 E−06 species.yr·m−2, the impacts are −30.9 % in SC1, −32.6 % in SC2, and −58.6 % in SC3. Human health damage in SC0 being 3.37 E−03 DALY, has been reduced in the timber home (SC1) is −44.2 %, of the Straw SFH (SC2) −39.2 %, and of the earth house (SC3) −67.1 %. This article shows that with current existing technological solutions GWP could be reduced in −80.9 %, ecotoxicity in −45.6 %, biodiversity loss in −58.6 % and human health in −67.1 %. Spanish Single-Family Houses built in timber, earth or straw-bale are real alternatives to current cement traditional building.The authors are grateful for the support provided by Life Cycle Thinking Group (LCTG) with the grant funded by the University of the Basque Country (GIU21/010)

Life Cycle Analysis Challenges through Building Rating Schemes within the European Framework

The decarbonisation of buildings is a crucial milestone if European cities mean to reach their mitigation targets. The construction sector was responsible for 38% of the GHG emissions in 2020. From these emissions, 11% is calculated to be currently embodied in building materials. In this context, an evaluation from a life cycle perspective is becoming increasingly necessary to achieve the objectives set. Currently, there are different building rating systems (BRS) at European level that allow the evaluation of the degree of sustainability of buildings. During this study, the authors have evaluated to what extent and how the most extended five BRS (NF Habitat HQE, VERDE, DGNB, BREEAM, and HPI systems) in the European framework have integrated the life cycle methodology during their evaluation process. Four methodologies have been used in the research in order to analyse these five systems: quantitative assessment, multi-level perspective, mapping–gap analysis, and expert interviews. Although each methodology has produced different results, the need to harmonise the evaluation criteria at the European level, the insufficient consistency of data software, and the availability of skilled LCA professionals for wider LCA market penetration, among others, should be highlighted. The quality and harmonised data of construction products is required for LCA to give aggregated and transformative results.This research was funded by the research project LOCAL-REGEN (PID2019-104871RB-C22), supported by the Spanish Ministry of Science and Innovation (Ministerio de Ciencia e Innovación) – State Research Agency/10.13039/501100011033

Setting baselines of the embodied, operational and whole life carbon emissions of the average Spanish residential building

The construction sector, responsible for 37 % of global greenhouse gas emissions and 36 % of global energy consumption, is transitioning towards a low-carbon and low-energy model. Measuring and optimising Operational Energy and related emissions in the use phase of buildings has entered both markets and regulations. However, the Embodied Energy within construction materials and respective maintenance and end-of-life processes is still in the research phase. Moreover, Global Warming Potential baselines per built square metre need to be defined in the construction sector, integrating operational and embodied impacts. This research has the main goal of identifying for the first time the Whole Life Carbon (WLC) emissions of the average Spanish residential buildings of the period 1981–2010, broken down into Embodied Carbon (EC) and Operational Carbon (OC). For this purpose, first, a regular average and homogenised average of existing European baselines was performed; next, the average Spanish residential building has been defined and modelled with a real sample from year 2013, and its emissions calculated as Scenario 0; and finally, five new scenarios have been compared in order to understand variations in WLC and their EC and OC contributions. This research shows for the average multifamily building apartment in Spain, with a mean net floor area of 73.1 m2, a WLC baseline of 1944 kg CO2-eq·m−2, 30.8 % (559 kg CO2-eq·m−2) being EC, and the remaining 69.2 % OC. In Scenarios 1 to 3, the following are identified: a WLC reduction of 26.0 % (9.2 % EC) by using wood window frames, 0.8 % (2.7 % EC) by laying a wood inner floor, and 16.1 % (1.0 % EC) by insulating walls with recycled cork. All three items are calculated together in Scenario 4, giving a 36.9 % WLC reduction (9.5 % EC). Finally, Scenario 5 was modelled upon Scenario 4 materials, complying with the upcoming European Energy Performance of Buildings Directive as if built in 2021, reaching a potential WLC reduction of 63.4 % (2.8 % EC) from the original Scenario 0. These figures support technical and policy trends towards minimising the impacts of buildings. Focusing on decarbonisation, targets of over 60 % appear feasible with existing market solutions. Reductions of >80 % are also derived from other impact categories, such as Ionizing Radiation, Marine Eutrophication, and Water Consumption, while Freshwater Ecotoxicity increases by 15 %. The 18 ReCiPe Midpoint indicators plus Energy Footprint, are reduced by an average of 50.4 %.The authors are grateful for the support provided by the Life-Cycle Thinking Group (LCTG) with the grant funded by the University of the Basque Country (GIU21/010). The authors are grateful for the funding provided by the Department of Architecture of the University of the Basque Country (UPV/EHU)

Life cycle analysis in building rating systems: strategies for decarbonization in Europe.

194 p.Impactos ambientales (huella de carbono, ecotoxicidad, pérdida de biodiversidad y daño a la salud humana) provocados por la edificación residencial española a través de la metodología de análisis de ciclo de vida en puntos intermedios y finales de impacto. Se analiza la edificación colectiva y unifamiliar.Se propone un valor de referencia de huella de carbono para la edificación residencial. Se analizan los factores para una transición sociotecnológica del sector. Se concluye que hay impactos de gran importancia para ser trasladados a las políticas y la reglamentación, además de las ya conocidas sobre huella de carbono

Current indicators and metrics hinder effective urban climate adaptation

Assessing the effectiveness of climate adaptation action is the focus of intense debate across scientific and policy arenas. Measurement is essential for effective adaptation management and operation, and indicators and metrics (I&M) have a pivotal role. Surprisingly, there are very few systematic efforts to understand the advances in the provisioning of adaptation I&M. Here we analyse 137 publications and 901 I&M sourced in the scientific literature to measure adaptation to climate change, particularly, in urban areas where governments are increasingly placing efforts to prepare populations and infrastructures. A lack of common terminology, standardisation, and reference guidelines has resulted in a field that is complex to track and understand. Furthermore, such complexity has led to diverse, context-specific and sometimes competing approaches to developing I&M. We argue that current I&M proposals are highly technical, not sufficiently grounded on real needs, and have little potential to collectively support effective urban climate change adaptation