Country Case Studies of the “Avoid-Shift-Improve” Strategies

Globally, countries with very different built environment contexts can pursue decarbonisation of their built environment sectors using the “Avoid-Shift-Improve” strategies.

CANADA

Dominant materials:

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Concrete and steel (commercial)

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timber (residential)

Current status:

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Canada has one of the cleanest grids for global manufacturing (82 per cent emissions-free) and uses more than 70 per cent less carbon than the global average for steel and aluminium (Environment and Climate Change Canada 2022). However, the electricity is mostly from hydropower, and further proposed expansion of dams is being challenged for degrading environmental and indigenous rights.

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Timber is re-emerging to replace concrete and steel in the residential sector, and there are world-first demonstrations for massive timber use in high-rise construction, but further development of sustainable binders is necessary.

Policy recommendations:

AVOID primary materials and move to a circular economy

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Construction represents a core sector for advancing the circular economy in Canada due to its economic importance, high material necessity and large quantities of waste (Council of Canadian Academies 2021).

SHIFT to bio-based materials

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Improve sustainable forestry practices if wood resources are to be more in demand.

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Use a mix of timber species to avoid a monoculture in forestry (for example, white spruce monocultures have replaced Acadian forest, leading to reduced biodiversity, diminished ecosystem function and negative cultural impacts for Indigenous people (Government of Canada 2021).

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Mandate increased use of agricultural cover crops and by-products for building materials.

IMPROVE conventional materials and processes

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Establish a Clean Infrastructure Challenge Fund to promote public procurement and demonstration of decarbonisation practices.

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Promote local, Canadian-made products such as Portland limestone cement, which contains up to 10 per cent less embodied carbon than imported cement and would avoid more than 1 million tons of carbon pollution each year.

FINLAND

Dominant materials:

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Concrete

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Timber and wood (residential)

Current status:

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Has reduced its emissions at a faster pace than the European Union average since 2005, with the largest reductions in manufacturing industries and construction. The sector’s share of total emissions fell from 16 per cent in 2005 to 11 per cent in 2019 (Jensen 2021).

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Has some of the world’s most ambitious building codes that support the transition to bio-based materials and net zero urban emissions.

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Initiated the use of neighbourhood-level carbon planning tools (AVA).

Policy recommendations:

AVOID primary materials and move to a circular economy

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Adopt policies and targets at the municipal and national levels for integrated decarbonisation across multiple scales of infrastructure and buildings.

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Use carbon tracking tools at the level of urban planning and regional ecosystems.

SHIFT to more sustainable bio-based materials

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Further develop sustainable forestry practices, as wood resources are in high demand, but overharvesting of raw timber needs to be replaced with more sustainable practices.

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Scale up the development and use of agricultural cover crops and by-products for building materials.

IMPROVE conventional materials and processes

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Improve data collection methods for building materials and processes, especially to promote re-use of materials.

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Build systems to collect data on operational energy costs and create platforms for users to track energy costs of material decisions.

GHANA

Dominant materials:

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Concrete masonry

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Metals (roofing)

Current status:

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The share of concrete masonry used for external wall construction has risen from 39 per cent to 64 per cent since 2000 (Ghana Statistical Service 2021).

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Metal sheets comprise 80 per cent of all housing roofing applications (Ghana Statistical Service 2021).

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Use of low-carbon earth masonry for wall construction declined 50 to 30 per cent since 2000 (Ghana Statistical Service 2021).

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Timber logging is an estimated two to three times above the legal annual allowable cuts set by the Ghana Forestry Commission (Oduro 2016).

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The electricity sector has shifted sharply from 64 per cent hydropower in 2015 to 66 per cent fossil fuel-based in 2020 (Ritchie, Roser and Rosado 2020).

Policy recommendations:

AVOID primary materials and move to a circular economy

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Invest in and market local building materials, with a focus on the partial or full substitution of concrete masonry products as well as improved infrastructure to recover high rates of local material waste in the timber and agricultural sectors.

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Provide research support and industrial incentives to encourage the use of locally available and low-carbon alternatives to Portland cement binders in concrete masonry products.

SHIFT to bio-based materials

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Progressively revise local building codes and standards to include near-term installation and performance guidelines for low-carbon, bio-based and earth masonry materials.

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Revise the building permit process to require mandatory minimum values for roofing insulation.

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Provide professional training and upskilling in the use of low-carbon, bio-based and earth building materials across the agriculture, manufacturing, design, construction, artisanal and waste management sectors.

IMPROVE conventional materials and processes

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Progressively revise local building standards and codes to include material specifications for embodied carbon and climate performance.

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Enact green procurement policies that support the use of low-carbon and locally available bio-based alternatives as aggregates, binders, reinforcing components or additives across masonry and timber products.

GUATEMALA

Dominant materials:

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Concrete block and steel

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Earth-based and biomass materials (vernacular traditions)

Current status:

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In Guatemala’s booming residential construction sector, between 2002 and 2018, the use of cement block increased 96 per cent, concrete 215 per cent and metal 191 per cent; meanwhile, the use of traditional mud declined 38 per cent and the use of agricultural and forest by-product materials (straw, sticks, or canes) fell 29 per cent (Guatemala INE 2002).

Policy recommendations:

AVOID primary materials and move to a circular economy

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Establish national building codes with regional compliance, and progressively revise local building standards and codes to include embodied carbon and climate performance.

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Support national and regional schools in architecture, engineering and industrial design to focus on the transition to circular principles for modular pre-fabricated concrete components, and encourage design for disassembly and re-use of components.

SHIFT to bio-based materials

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Develop standards and conduct certifications of regional and traditional earth-based and bio-based structural and additive materials based on local species, to engender confidence in these materials for multi-storey construction among builders who need to densify urban settlements.

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Facilitate cooperation among small, local and large-scale cement industry players and regional agricultural producers in developing novel (bio-based) concrete admixtures to reduce binder requirements, while also capitalising on and upcycling problematic biowaste from regional agriculture.

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Develop standards for production and regulation of regional bamboo, forest by-products and biomass.

IMPROVE conventional materials and processes

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Facilitate domestic partnerships with multinational producers towards establishing net zero cement production based on best available technologies by electrifying with renewables.

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Capitalise on the regional momentum of CEMEX and others towards further research and demonstration of carbon capture and storage at cement manufacturing plants, with renewable electrification.

India

Dominant materials:

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Bricks, concrete and steel

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Rammed earth and mud brick (rural areas)

Current status:

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India’s buildings sector is expected to grow 20 million square metres between 2015-2030, (Global Buildings Performance Network 2014).

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Bricks and traditional materials still play a significant role in rural areas, but with rapid urbanisation, cement and concrete have become commonly used construction materials in India (Venkatarama Reddy et. al 2003, Praseeda et. al 2016).

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The Indian government has launched several initiatives to promote sustainable and eco-friendly building materials, in order to use secondary cementitious materials such as fly ash in bricks and green concrete.

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Women comprise only 12 per cent of the building sector workforce, mostly in the least desirable jobs in the informal sector, with a gender pay gap of between 30 and 40 per cent (Primus Partners, 2023).

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The use of pre-fabricated construction materials is gaining popularity in the country due to the higher material efficiencies and lower on-site emissions and disruption.

Policy recommendations:

AVOID primary materials and move to a circular economy

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Establish enforced policies that require companies to use recycled materials in their production processes and to design products for re-use or recycling, which would reduce waste and resource consumption.

SHIFT to bio-based materials

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Address supply chain challenges by promoting upcycling of waste from food crops that can be used as bio-based materials and by encouraging investment in the processing and manufacturing infrastructure for biomaterials

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Focus on local needs by supporting research and development of bio-based materials that address specific challenges faced by communities in India; address negative perceptions through design and marketing.

IMPROVE conventional materials and processes

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Strengthen environmental regulations to reduce greenhouse gas emissions and resource consumption in the manufacturing sector using regulations on energy efficiency, water use and waste disposal.

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Peru

Dominant materials:

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Concrete and steel (urban housing)

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Earth-based materials and bio-based materials (rural housing)

Current status:

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In urban and rural areas, there is a shift towards concrete and steel construction, replacing traditional adobe, mudwall, wood and cane buildings. These new construction techniques often do not respond to local climate and building traditions. Seismic construction is a crucial consideration.

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Around 66 per cent of residential construction in Peru is in the informal sector (Espinoza and Fort 2020), which in the consolidation phase employs mineral-based materials.

Policy recommendations:

AVOID primary materials and move to a circular economy

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Incentivise the adaptive re-use of existing buildings and use of circular materials with better credit systems and labels.

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For the informal housing sector, support the participation of architects and engineers and the training of local populations in topics such as design for disassembly and the use of low-impact and local materials.

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Support digitalisation as an opportunity to reduce waste production (currently used mainly in large projects).

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Local governments should prioritise the research and development of design for disassembly strategies for structural elements.

SHIFT to bio-based materials

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Promote sustainable construction practices by employing biodegradable biomaterials and prioritizing sourcing raw biomaterials while preserving vernacular architecture in rural areas.

IMPROVE conventional materials and processes

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Encourage research and development to transition traditional seismic materials towards lower emissions and re-evaluate local construction techniques through technology transfer.

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Support job creation opportunities at the end-of-use phase, from formalising existing recyclers to creating new, formal jobs related to the construction industry.

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Implement more transfer plants in cities and allow urban landfills to receive construction, renovation and demolition materials, to prevent illegal dumping sites.

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Improve certifications, credits and labels.

Senegal

Dominant materials:

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Concrete masonry

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Metal (roofing)

Current status:

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Concrete masonry in Senegal accounts for nearly 70 per cent of wall construction and 71 per cent of roofing materials (PEEB 2021b).

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Metal sheets (38 per cent) are slightly more prevalent than concrete masonry (32 per cent) in rural roofing assemblies (ANSD 2021).

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Only 5 percent of local timber demand is met by local production, from threatened tree species (Berthome, Silvertre and Kouame 2013).

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Although fossil fuels supply 86 percent of electricity, the supply from renewable sources has increased (6 percent hydropower, 6 percent solar, 0.33 per cent wind and other renewables) (Ritchie, Roser and Rosado 2020).

Policy recommendations:

AVOID primary materials and move to a circular economy

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Progressively revise local building standards and codes to include embodied carbon and climate performance.

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Provide research support and industrial incentives to encourage the use of locally available and low-carbon alternatives to Portland cement binders, including supplementary cementitious materials to improve the stabilisation and hygrothermal performance of masonry products.

SHIFT to bio-based materials

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Invest in locally available low-carbon fuels for cement production

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Enact government mandates promoting the use of local bio-based and earth masonry in green public procurement projects.

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Educate finance and insurance companies working in the building sector about the positive impacts of low-carbon buildings, and pro-actively incentivise building owners who adopt such technologies, in association with standards such as the Africa Research and Standards Organisation’s recently ratified compressed earth block standard (ARSO 2018).

IMPROVE conventional materials and processes

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Promote finance and industrial investment in the research and development of technological innovation of cement, metal and timber products that are consistent with low greenhouse gas emissions and resilient local building material sectors.