9 ways in which One Click LCA Planetary can reduce embodied carbon in cities

Lessons from the City Policy Framework

“Embodied carbon contributes about 11 % of all global carbon emissions and as a consequence of urbanization, practically all of it is caused by demand in cities. Unless the construction sector’s embodied carbon intensity is drastically cut, embodied carbon from new buildings, renovations and infrastructure until 2060 may exceed 230 gigatons – more than six years of today’s global fuel combustion carbon emissions..”

City Policy Framework for Dramatically Reducing Embodied Carbon

This was the stark warning contained in City Policy Framework for Dramatically Reducing Embodied Carbon, published recently by the Carbon Neutral Cities Alliance and One Click LCA, in cooperation with Architecture 2030.

The report contains 52 policies that cities can adopt in an effort to reduce embodied carbon. Many have already been applied in projects in cities across the world, including New York, Vancouver, London, Stockholm, Dubai, Singapore.

The policies are grouped into seven categories from zoning and land use to infrastructureEach policy is scored on its performance in the following categories so cities can evaluate them: carbon impact, cost-efficiency, implementability, and enforceability.

In the past, cost and implementability have been barriers to large-scale adoption of the life-cycle assessment approach to reducing carbon impacts. Now there’s a free, easy-to-use tool that helps everyone, everywhere decarbonize their materials design: One Click LCA Planetary.

With more cities implementing new policies to achieve their embodied carbon targets, this article outlines how One Click LCA Planetary can be used to implement nine of the City Embodied Carbon policies.

Zoning and land use policies

1: Declare carbon impacts of tender proposals

When a city is selling land or granting long term leases on a competitive basis, it can apply life-cycle carbon (comprising materials and energy) efficiency of the proposed project as a scoring factor to the bids with a 30% weighting, or another significant weighting as appropriate. Bidders must calculate and declare the carbon impact of their proposal.

(Policy Z3: Carbon-scored Land Sales Competitions, City Policy Framework for Dramatically Reducing Embodied Carbon, page 47)

Use One Click LCA Planetary to:

Declare carbon impacts of tender proposals

With Planetary, you can calculate the cradle-to-gate embodied carbon impacts (A1-A3) and materials efficiency of your building design. This early life-cycle stage is the most critical phase for embodied carbon. Demonstrating higher measured carbon efficiency with One Click LCA Planetary may help you in the tender process, and allow you to discover the cost-optimal carbon reductions for projects.

In addition, One Click LCA Planetary allows you to compare designs and their carbon impacts. Demonstrating further reductions of embodied carbon against a proposed project may also be advantageous for your project bid.

Building regulation and supervision policies

2: Comply with maximum life-cycle carbon limits

Set limits on the maximum life-cycle carbon that new buildings can emit during their defined lifetime. This can be for whole life-cycle carbon (including operational carbon) or embodied carbon.

(Policy R1: Life-cycle Carbon Limits For New Buildings, City Policy Framework for Dramatically Reducing Embodied Carbon, page 59)

Use One Click LCA Planetary to:

Check whether you’re within your GWP limit

Results for GWP (Global Warming Potential) in One Click LCA Planetary are given in tons of CO2 and kg of CO2 per m2 for life-cycle stages A1-A3. They are broken down by materials category and given as a total for your design. These results will show you if you are above or below the maximum limit set for the project.

If you are above the limit, you will be able to use Planetary to identify hotspots for carbon emissions and optimize your design to reduce those impacts.

3: Apply performance-based concrete requirements, with carbon performance limits

Implement a comprehensive low carbon cement and concrete policy that shall:

  • Permit performance-based concrete requirements to be always used
  • Replace water to cement ratios with durability and shrinkage requirements, eliminating nonperformance-based requirements that lead to increased use of cement
  • Set maximum carbon performance limits for concrete by strength classes

Encourage applying strength evaluation time at 90d not 28d to enable broader use of secondary binders (e.g. fly ash or blast furnace slag).

(Policy R2: Low Carbon Cement And Concrete Policy, City Policy Framework for Dramatically Reducing Embodied Carbon, page 62)

Use One Click LCA Planetary to:

Find the optimal balance between the use of cement and concrete and other materials

Using the extensive library of EPDs, local/regional and generic datasets in One Click LCA Planetary will allow you to choose materials and products in line with project specifications. You can then find the optimal balance between the use of cement and concrete and other materials categories such as steel and wood.

If a resource isn’t available, you can use Planetary to make a request directly to a manufacturer to create an EPD for their product. The resulting EPD will be included in the database and can then be used for your calculations.

4: Declare key materials mass for planning applications

Require declaration of key material mass per m2/square foot of building to be filed for the planning permit process at the occupancy permit application stage for new buildings and extensions of at least 300 m2 (3,300 square feet), or as appropriate considering building sizes within the city.

(Policy R6: Construction Materials Efficiency Declaration, City Policy Framework for Dramatically Reducing Embodied Carbon, page 72)

Use One Click LCA Planetary to:

Report the materials mass for your design

The mass of materials for your design is one of the key elements of the results report in One Click LCA Planetary. It is displayed per materials category and as a total for your design in tons and kg per m2. Planetary covers the 10 most carbon-intensive materials categories. Limiting their mass will result in both carbon savings and cost savings.

5: Use standardised measures to report life-cycle carbon emissions

Require all projects to calculate and report their life-cycle carbon emissions using a standardized measure, separating embodied and operational carbon.

(Policy R9: Life-cycle Carbon Calculation And Reporting, City Policy Framework for Dramatically Reducing Embodied Carbon, page 78)

Use One Click LCA Planetary to:

Model, measure and communicate carbon impacts of your project

For “upfront” carbon reporting requirements, One Click LCA Planetary can be used to measure and communicate the A1-A3 impacts of your design. You can use Planetary to quickly and easily model different designs and report the emissions for each option in a standard format allowing direct comparison.

Procurement policies

6: Limit carbon intensity for major materials groups

Set carbon intensity limits for key materials for the major construction material groups for all city projects and implement in public procurement. Ensure the same requirements are enforceable also for construction projects where the city is buying or long-term leasing the building. These can be demonstrated using Environmental Product Declarations for example. These would be required when a project is bid, and then completed, so that the purchase is verifiable.

(Policy P1: Carbon Limits For Key Building Materials For City Projects, City Policy Framework for Dramatically Reducing Embodied Carbon, page 80)

Use One Click LCA Planetary to:

Ensure key materials comply with carbon intensity limits

Planetary is built on One Click LCA, the world’s leading life-cycle assessment software. It includes all local EPDs as well as regional and generic datasets. These resources can be used to select materials with specified carbon limits. In fact, the intuitive software allows filtering materials based on their carbon emissions, from very high to very low, making it even easier to choose sustainable options.

Infrastructure policies

7: Reduce materials use and carbon in early design phase

Infrastructure projects can reduce both materials use and carbon significantly. As projects vary, targets must be set on a project by project basis. They can be set as part of early design. The later design and construction must then meet these auditable targets. This can be started with accounting requirement if needed. This requirement can also apply to municipal funding requests.

(Policy I1: Early Design Carbon Targets For Infrastructure, City Policy Framework for Dramatically Reducing Embodied Carbon, page 92)

Use One Click LCA Planetary to:

Optimise materials used in infrastructure projects

While infrastructure projects cannot be modelled in Planetary per se, you can use the materials resources to find and choose what you use in your project. The volume of materials used in infrastructure projects can be so vast that even small changes in the environmental performance of the materials you use or specify can have significant impacts on your embodied carbon emissions. And if a material you want to use isn’t in our database, you can request that the manufacturer creates an EPD from within the software.

Municipal building policies

8: Implement an embodied carbon cap for a building’s life-cycle

New and long term leased city buildings can be subject to a cap on the embodied carbon they can emit during their life cycle. Alternatively, the implementation can set a reduction percentage based on a reference building that considers the site conditions and building type.

(Policy M2: Embodied Carbon Limits For New and Leased Buildings, City Policy Framework for Dramatically Reducing Embodied Carbon, page 119)

Use One Click LCA Planetary to:

 Identify materials and elements responsible for excessive emissions

Planetary allows you to calculate the cradle-to-gate embodied carbon impacts of your building, as well as allowing you to compare it directly with a reference building. If your design exceeds the cap set for the project, you can easily identify the materials category or building element that is responsible for excessive emissions and make adjustments to reduce those impacts.

9: Set carbon as design competition award criterion

Setting carbon as an award criterion for design competitions and design & build competitions for city building can improve the proposals and help to find innovative solutions without having to prescribe measures, by encouraging the market to offer them.

(Policy M3: Use Carbon As A Criterion For Design Competitions, City Policy Framework for Dramatically Reducing Embodied Carbon, page 121)

Use One Click LCA Planetary to:

Optimise embodied carbon performance in the early life-cycle stages

Displaying positive results for embodied carbon performance in the early life-cycle stages will set your project up for success throughout its life. With One Click LCA Planetary you can iterate your design and material selection to find the optimal solution to meet your project objectives as well as reducing carbon emissions. Choosing low carbon materials while also considering the quantity of materials you use is key to unlocking carbon reductions. The results report in Planetary will provide evidence of both carbon performance and materials efficiency for your design.

What’s next?

These are just some of the ways in which Planetary can help you decarbonize your building materials. To learn more about embodied carbon, review all 52 policies, and find out what other resources are available, please visit www.embodiedcarbonpolicies.com. If you don’t already have an account with One Click LCA Planetary, you can set one up free today at www.oneclicklca.com/planetary and see how you can start reducing the embodied carbon impacts of your projects.

One Click LCA is running a free Introduction to Planetary webinar on Wednesday 29th July at 2pm BST. Places are limited so register today.

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