Concrete Masonry Carbon Calculator
Sustainability, LEED, Green Construction
Andrea Boddy, EMBA, PEng, Andrea Boddy Consulting
Robert Munro, PEng, Owner, Concrete Advice
Canadian Concrete Masonry Producers Association Presents: Concrete Masonry Carbon Calculator
Andrea Boddy, Robert Munro
Sustainability. LEED. Green Construction.
These words, once responded to with a “What’s that?” are now known and understood throughout the Canadian construction industry.
As such, demand for publicly accessible material ingredients and related environmental and health impact is growing. LEED v4 Materials and Resources credits move away from rewarding single product attributes to taking a life cycle approach. This is a stimulus for further transparency, exploring leading frameworks in material transparency and the benefits and challenges associated with product disclosure.
The Canadian Concrete Masonry Producers Association (CCMPA) has been leading the way in terms of Canadian construction material suppliers with their commitment to supporting this evolution in sustainable design and environmental transparency. The association produced its third-party, Canadian industry-average business-to-business Type III environmental product declaration (EPD) for concrete masonry unit (CMU) products in 2014.
CCMPA’s board of directors has taken another step exhibiting its commitment to lowering carbon and increasing environmental transparency in construction with the development and launch of the CCMPA Carbon Calculator.
For years, designers have been making the decision to specify concrete masonry wall assemblies in their designs for user comfort, safety, superior resistance to disaster/fire/mould, acoustic benefits and operational energy-efficiency – among other things.
Today, they also have the opportunity to choose concrete masonry wall assemblies for carbon transparency. CCMPA’s free, downloadable Carbon Calculator assists with estimating the carbon footprint of concrete masonry designs:
Considering Concrete’s Carbon Footprint
Portland cement itself is energy intensive to produce, but portland cement is a minor component of concrete, concrete masonry units and masonry mortar. The largest volume of these materials is the low carbon footprint aggregate, which is locally sourced.
Owners, developers, constructors and other participants in building construction will be more and more dollar-motivated to understand CO2 implications when making building envelope decisions
Many producers are also using portland-limestone cements that have 10% less clinker and are replacing some of the portland cement with supplementary cementitious materials produced from industrial byproducts such as slag or fly ash, further reducing the portland cement content and increasing the properties of already extremely resilient and durable concrete products.
Figure 1. Carbon Calculator Primary Inputs»
The most important consideration when selecting concrete masonry construction is that concrete materials can be key components of the most sustainable structures. It is the long-term performance of the resulting structure over its life cycle that determines the total impact of a building on the environment, and concrete masonry structures have proven efficiency and durability for the long run. Even at the end of their life, concrete masonry structures can be recycled and avoid the landfill.
The CCMPA cradle-to-gate Carbon Calculator provides only a part of the big picture of environmental impact, but transparency and accurate information is an important building block of a sustainable design.
What it Does
Reviewed by Athena Sustainable Materials Institute, a non-profit think tank bringing life cycle assessment to the construction sector, the CCMPA Carbon Calculator downloadable tool:
- estimates the cradle-to-gate equivalent carbon content per square metre of masonry wall;
- is based on available published environmental data on products involved in concrete masonry construction;
- comes with a simple reference, assumptions and limitations document for full environmental and technical transparency; and
- provides flexibility to input climate zone, wall size/area, material volumes and types, and to return a cradle-to-gate estimate of the CO2 footprint for that construction.
The tool simplifies many of the steps in calculating the equivalent carbon content by providing default values for many of the required inputs. In addition, the tool calculates the minimum insulation thickness required for each Energy Star climate zone, for when a more detailed energy analysis of the building is not available.
Three different wall types can be selected; two exterior insulated and an uninsulated interior fire wall. Rebar and degree of grouting are selectable. The tool ensures that, at a minimum, all rebar cavities are grouted. Both normal and light weight block are selectable and block depths of 100 to 300 mm (4" to 12") are included. There is even a provision allowing the block producer to include any carbon sequestration during production. Innovative block producers are finding ways to recycle (sequester) CO2 during block-production, creating further carbon off-sets for each block produced. Examples include Carboclave (boehmerblock.com/carboclave.asp) and CarbonCure (carboncure.com). Carbon sequestration is a process of inserting captured carbon dioxide into CMU during manufacture as a way to sequester or trap it in order to prevent it from being emitted into the atmosphere, contributing to greenhouse gas emissions.
The Carbon Economy
Very soon, the Carbon Calculator may be of interest for more than the spirit of sustainable design. The carbon economy has landed in Canada. And the dollars are real. Provinces have adapted either a Cap & Trade system (Ontario, Quebec) or a carbon fee/tax approach (British Columbia, Alberta).
According to the Quebec government1: The primary objective of the C&T system is to reduce GHG emissions in the highest emitting sectors, i.e., transportation, industry and building, by promoting energy efficiency as well as the use of energy from renewable sources. The carbon market therefore stimulates creativity as well as technological and business innovation by fostering the emergence of new low carbon drivers for economic development.
Figure 2. Canadian Building Code Climate Zones»
In a Cap & Trade system2:
Government puts a firm limit, or cap, on the overall level of carbon pollution from industry and reduces that cap year after year to reach a set pollution target. As the cap decreases each year, it cuts industry’s total greenhouse gas emissions to the limit set by regulation, and then forces polluters that exceed their emissions quota to buy unused quota from other companies.
With a carbon fee/tax approach2:
A carbon fee is a charge placed on greenhouse gas pollution mainly from burning fossil fuels. This can be done by placing a surcharge on carbon-based fuels and other sources of pollution such as industrial processes… Under this system, the price to pollute sets the strength of the economic signal and determines the extent to which green choices are encouraged.
By the Numbers3
- Carbon tax rates in British Columbia have been C$30/MT (C$27.2/short ton) since 2012 and the system has been in place since 2008 at C$10/MT (C$9.1/short ton) followed by C$5/MT (C$4.5/short ton) annual increases.
- Quebec Cap & Trade came in to being January 1, 2013 and the following year was joined by markets in California. Emission allowance sales occur four times per year. The first floor price was C$10.75/MT (C$9.75/short ton) in 2013. At an auction in February 2016, C$17.64/MT (C$16.00/short ton) was realized.
- Alberta’s carbon tax will started at C$20/MT (C$18.1/short ton) in 2017, will move to C$30/MT (C$27.2/short ton) in 2018, with price increase for future years set at 2% plus inflation.
- Ontario’s Cap & Trade took effect January 2017.
- Most provinces have systems involving free allocations and rebates back to industry to support reduction implementation, ensure competitiveness, and other rationales during the transition years, but these freebies will not last forever if climate change commitments and targets are to be reached.
- Furthermore, these carbon values are forecast to increase exponentially. It makes sense that as the volume of emissions to be reduced increases, it will cost more per metric tonne to do so. As projected by Ivey Business School3, if it costs C$21/MT (C$19.1/short ton) to reduce 100MT (110 short tons), it is likely to cost C$175/MT (C$159/short ton) to reduce 290MT (320 short tons).
- No provincial jurisdiction will be carbon economy free4: In October 2016, Prime Minister Trudeau announced the Liberal government’s plan to setup a C$50 per tonne (C$45.4/short ton) of carbon dioxide equivalent as a floor price by 2022. Any province that does not meet or exceed that price through a direct price on carbon or cap-and-trade system will have that imposed upon them.
The Canadian carbon economy will continue to evolve. Owners, developers, constructors and other participants in building construction will all be more and more dollar-motivated to understand the CO2-implications when making building envelope decisions. And CCMPA will be ready, with transparent, validated product information and proven tools to assist with carbon-estimating.
Crossing the Border
For the American readers, never fear. Benefits of this carbon calculator are not remaining north of the border. Forwarding-thinking California block producer Angelus Block is working with Andrea Boddy Consulting and Concrete Advice to develop a carbon calculator specific to concrete masonry construction with their products and California building and energy codes. The company sees the investment in this carbon estimating tool as both a service they need to offer to their valued design community, as well as the responsibility of an environmentally-transparent building materials producer and supplier. See sidebar
- mddelcc.gouv.qc.ca/changements/carbone/Systeme-plafonnement-droits-GES-en.htm, Gouvernement de Quebec, 2016.
- Carbon tax or cap-and-trade? David Suziki Foundation. davidsuzuki.org/what-you-can-do/carbon-tax-cap-trade/
- Squaring the Circle: Canadian GHG Emissions. Booth, Paul; Boudreault, Felix; Frankel, Christopher. Lawrence National Centre for Policy and Management – Ivey Business School at Western University. 2016 (ghg-emissions-report-sqauring-the-circle.pdf)
- thestar.com/news/canada/2016/10/04/justin-trudeau-defends-carbon-tax-strategy.html, Oct 4, 2016, Bruce Campion- Smith, Globe & Mail.
The carbon calculator allows for transparency in concrete block material useage»
Andrea Boddy, EMBA, PEng, is the founder of Andrea Boddy Consulting, a boutique advisory firm focused on the Canadian concrete construction industry with expertise in marketing, strategy, sales, coaching and advisory services.
With more than 16 years of technical, sales and operational leadership in Canada and the United States for North America's largest building materials producer, Boddy brings a unique cross-section of knowledge and skills to her clients’ benefit and profitability. A published author, Boddy has written nine technical papers for various industry research journals.In addition to her consulting practice, Boddy is a senior advisor for Bridge Check Canada, an innovative concrete inspection, testing and forensics firm in Toronto. She is a past board member of ACI Ontario and Concrete Ontario. Boddy holds a BASc and MASc from the University of Toronto and an MBA from Queen’s University. firstname.lastname@example.org | 647.302.3852
Robert Munro, PEng, owner of Concrete Advice, a company dedicated to improving concrete performance and quality through consulting, training and education. After graduating in Civil Engineering at the University of Toronto and four years with the Canadian Home Builders’ Association as a technical expert on the R-2000 Super Energy Efficient Housing Program, Munro spent over 27 years with Lafarge in technical service roles. Responsibilities included troubleshooting problems with all types of concrete and developing new applications and products, culminating in work on the main concrete specifications. He has also travelled to Western and Eastern Canada and the US, troubleshooting, promoting and visiting significant projects and applications.