A Comparative Study on the Life Cycle Assessment of New Zealand Residential Buildings

In New Zealand, housing is typically low density, with light timber framing being the dominant form of construction with more than 90% of the market. From 2020, as a result of the global pandemic, there was a shortage of timber in New Zealand, resulting in increased popularity for light steel framing, the main alternative to timber for housing. At the same time, the New Zealand government is committed to sustainability practises through legislation and frameworks, such as the reduction of whole-of-life carbon emissions for the building industry. New Zealand recently announced reducing its net greenhouse gas emissions by 50% within 2030. Life cycle assessment (LCA) is a technique for assessing the environmental aspects associated with a product over its life cycle. Despite the popularity of LCA in the construction industry of New Zealand, prior research results seem varied. There is no unified NZ context database to perform an LCA for buildings. Therefore, in this paper, a comprehensive study using LCA was conducted to quantify and compare the quantity of carbon emissions from two commonly designed houses in the Auckland region, one built from light timber and the other from light steel, both designed for a lifespan of 90 years. The cradle-to-cradle system boundary was used for the LCA. From the results of this study, it was found that the light steel house had 12.3% more carbon in total (including embodied and operational carbons) when compared to the light timber house, of which the manufacturing of two houses had a difference of 50.4% in terms of carbon emissions. However, when the end-of-life (EOL) analysis was included, it was found that the extra carbon could be offset due to the steel’s recyclability, reducing the amount of embodied carbon in the manufacturing process. Therefore, there was no significant difference in carbon emissions between the light steel and the light timber building, with the difference being only 12.3%.

Designing a sustainable, medium density housing solution that is an affordable alternative for developers

<p>It has been acknowledged that there is a housing crisis in New Zealand (NZ), particularly in the large urban centres (Hulse, 2015). As a solution, medium density housing developments are becoming more prevalent. However, these developments are controversial in a country that prides itself on its generous housing and open spaces. Sustainability is also an issue in the NZ architectural environment. NZ is a small country isolated in the South Pacific, so ‘sustainable’ materials must often be imported, this long-distance transportation increasing their cost as well as their carbon footprint. Many products also reference ‘green washing’, with companies misleading consumers into believing their product is environmentally friendly (EnviroMedia Social Marketing, 2017). Legitimately sustainable technologies and materials are often seen as unaffordable, and people (particularly property developers) are not prepared to consider eco-friendly building practices if they do not believe they will get an economic return for their investment. Because of these factors, New Zealand does not have a dynamic and sustainable medium density housing vernacular. The current research addresses these issues by seeking out materials and technologies for use in a theoretical medium density housing development. The project focuses on finding innovative and sustainable potential solutions for architects, developers, property buyers, and wider community stakeholders. It argues that architectural materials and processes should aim to fit as closely as possible within cradle-to-cradle frameworks involving closed loop production, construction and reuse systems (Braungart & McDonough, 2010).</p>

Designing a sustainable, medium density housing solution that is an affordable alternative for developers

<p>It has been acknowledged that there is a housing crisis in New Zealand (NZ), particularly in the large urban centres (Hulse, 2015). As a solution, medium density housing developments are becoming more prevalent. However, these developments are controversial in a country that prides itself on its generous housing and open spaces. Sustainability is also an issue in the NZ architectural environment. NZ is a small country isolated in the South Pacific, so ‘sustainable’ materials must often be imported, this long-distance transportation increasing their cost as well as their carbon footprint. Many products also reference ‘green washing’, with companies misleading consumers into believing their product is environmentally friendly (EnviroMedia Social Marketing, 2017). Legitimately sustainable technologies and materials are often seen as unaffordable, and people (particularly property developers) are not prepared to consider eco-friendly building practices if they do not believe they will get an economic return for their investment. Because of these factors, New Zealand does not have a dynamic and sustainable medium density housing vernacular. The current research addresses these issues by seeking out materials and technologies for use in a theoretical medium density housing development. The project focuses on finding innovative and sustainable potential solutions for architects, developers, property buyers, and wider community stakeholders. It argues that architectural materials and processes should aim to fit as closely as possible within cradle-to-cradle frameworks involving closed loop production, construction and reuse systems (Braungart & McDonough, 2010).</p>

Determining the Environmental Potentials of Urban Pavements by Applying the Cradle-to-Cradle LCA Approach for a Road Network of a Midscale German City

This study used a cradle-to-cradle Life Cycle Assessment (LCA) approach to evaluate the environmental potentials of urban pavements. For this purpose, the urban road network of the City of Münster (Germany) was selected as the case study, and comprehensive data for several phases were collected. The entire road network is composed of flexible pavements designed according to specific traffic loads and consists of main roads (MRs), main access roads (MARs), and residential roads (RSDTs). Asphalt materials, pavement structures, and maintenance strategies are predefined for each type of road and are referred to as “traditional” herein. Some pavement structures have two possible maintenance strategies, denoted by “A” and “B”, with distinguished periods of intervention. To evaluate the impact of using recycled materials, we considered alternative pavement structures composed of asphalt materials containing a greater amount of reclaimed asphalt pavement (RAP). The study was carried out considering analysis periods of 20, 50, 80, and 100 years and using two indicators: non-renewable cumulative energy demand (nr-CED) and global warming potential (GWP). The results show that the use of higher amounts of RAP can mitigate negative environmental impacts and that certain structures and maintenance strategies potentially enhance the environmental performance of road pavements. This article suggests initiatives that will facilitate the decision-making process of city administrators to achieve more sustainable road pavement constructions and provides an essential dataset inventory to support future environmental assessment studies, particularly for European cities.

Exploring traditional thread-making and simple weaving used in OPP lamination film upcycling for ecologically responsible textile craft

Aiming for sustainable eco-friendly craft/design practice, this design research explored upcycling-practice of OPP plastic waste using traditional technology to create an alternative raw material for textile craft. By combining cultural investigation into the textile-making tradition with Cradle-to-Cradle design principles, we identified the potential of traditional technology as an ecologically responsible production process. We also developed upcycling method to process OPP plastic waste material. This research resulted in: (1) thread-making techniques that produce different sizes of thread as raw materials and hand-woven textile, (2) revitalized endangered indigenous technology of craft-making that had been a part of human-nature ecology, (3) eco-design education that can be accepted by local textile craft community, and (4) textile craft products that express the local identity and promote environmental care.

A critical review on circular and regenerative urban areas

Circular economy (CE) has gained relevance as a new economic-environmental paradigm. Despite their key role in this model, managing cities towards CE has taken different meanings, approaches, concepts and methods. Therefore, this study aims to clarify circularity approaches to urban areas, by identifying main trends and exploring potential organization into a framework for policymakers and urban managers. We first conducted a systematic literature review (SLR) to understand limits and divergences when spatially expressing circularity. Four approaches covering different possibilities regarding circularity in urban areas stood out: (i) specific flows within a circular city; (ii) flows integration for resource looping; (iii) planning the transition from linear to circular cities; and (iv) concepts of circular or regenerative urban areas. We then hypothesized that one of these concepts, the Cradle to Cradle (C2C) approach, embraces the multiplicity of quantitative and qualitative requisites needed for developing circular urban areas. Our contribution, in the second part of the paper, organizes the requisites and indicators raised during the SLR according to the C2C principles into a draft framework to enable optimization and integration of different flows with human activities to various urban and socioeconomic contexts.

Weighting with Life Cycle Assessment and Cradle to Cradle: A Methodology for Global Sustainability Design

Sustainable product design uses methodologies focused on eco-effectiveness and eco-efficiency for the proposal of innovative technological solutions and for the control of environmental impacts during the product life cycle. One of the main drawbacks of such techniques is their qualitative nature, associated with a decision-making process that is sometimes arbitrary, or with unverifiable data; this means that several complementary tools are currently being used to reduce the error in the results obtained. This situation makes the unification of procedures necessary. In this context, this research develops a methodology for the sustainable design of industrial products that integrates life cycle assessment (in its environmental, economic and social application) and cradle-to-cradle techniques. For this purpose, a new assessment process is proposed, based on damage, developing LCA+C2C endpoint indicators. The methodology is subsequently verified in a case study of products for sustainable mobility (city trike electric). The results show that an integrated LCA+C2C assessment can help to propose more balanced sustainable strategies and would be a suitable method to measure tradeoffs between economic, social and environmental results, for practical purposes and future redesigns. The unified method provides a procedure to design a solution with a trade-off between eco-efficient and eco-effective criteria; it also simplifies the design phases, facilitates the interpretation of the results and provides a quantitative scope to the cradle-to-cradle framework.

Phosphorus Recovery from Sewage Sludge Ash Based on Cradle-to-Cradle Approach—Mini-Review

The wastewater treatment process generates large amounts of P-rich organic waste (sewage sludge (SS)). The direct application of SS in agriculture, being controversial, is gradually being replaced by incineration, leading to the concentration of both P and heavy metals in the solid residual-sewage sludge ash (SSA). The novel closed-loop, cradle-to-cradle (C2C) approach leads to maintaining P production at current levels and counteracts its depletion in the future. The aim of this review is the presentation of the implementation of the C2C approach for P recovery. The paper focuses on steps that comprise P C2C, starting from the SS properties, being a derivative of wastewater type and treatment processes, to SS pre-treatment and finally leading to certified P-fertilizers production from SSA by application thermochemical or wet chemical extraction technologies. Examples of SSA treatment technologies and the final products are provided. It has been summarized that future research should focus on the production of SSA-based fertilizers aligning with the C2C concept and determining its effect on the various agriculture and horticulture crops.