Nelson publishes unique guide to low-carbon building materials – Nelson Star

The City of Nelson has released a guide for home builders to help them choose low-carbon building materials.

“Its author, the city’s climate resilience planner, Natalie Douglas, says using low-carbon building materials to build energy-efficient homes could lead to substantial reductions in greenhouse gas emissions. Greenhouse.

But how to do that, and what materials to use, is an emerging science.

After a year of research, the city’s Material Carbon Emissions Guide was released in March, along with another document, the Benchmarking Report. Douglas presented them to the board at its May 24 meeting.

“It’s new and timely work,” she said. “We are one of the few communities in Canada to have conducted localized research on embodied carbon. This is a topic that is already transforming the construction industry.

The guides are intended to help builders and the city tackle the problem of embodied carbon – greenhouse gas emissions resulting from the extraction and manufacture of building materials such as concrete, foam insulation and steel.

The conventional way to measure a building’s carbon footprint is to analyze its energy efficiency after it is built and inhabited. These emissions, created by heat escaping through the building envelope, are called operational carbon emissions.

But counting these emissions misses the significant footprint in building materials or embodied carbon emissions.

Nelson Next, the city’s climate plan, makes low embodied carbon in buildings a priority. Douglas’ work is managed by the City of Nelson and funded by FortisBC.

Benchmarking report

The benchmarking report contains the results of the work carried out by Douglas last year.

She analyzed the amount of embodied carbon in 34 homes in Nelson and Castlegar, finding that these homes had, on average, 28.8 tonnes of embodied carbon emissions associated with construction before anyone had even lived in the home.

The study highlighted some of the most carbon-emitting building materials based on data from the 34 homes. These included various types of concrete, insulation and exterior cladding. The results also include details about other types of concrete, insulation and cladding that have smaller footprints.

The work was done using a specialized tool developed by the Builders for Climate Action group in Ontario.

The benchmarking report is available at https://bit.ly/38Eum8J.

Materials Carbon Emissions Guide

The Material Carbon Emissions Guide contains new work that has been done since the fall.

It offers an analysis of eight materials: concrete, insulation, siding, interior surfaces, windows, framework, roofing and structural elements (steel and wood posts and beams).

Of these materials, concrete has the highest total average carbon emissions per home at 35%, according to homes in the study. The majority of emissions associated with concrete come from the production of one of its main ingredients, cement. The report gives details of emissions related to different types of cement, including alternative low-carbon types.

Similar analyzes are applied to the seven other types of materials listed above, with product classifications.

Douglas told the council that in writing the report she engaged with around 50 builders and other building professionals in Castlegar and Nelson in the fall of last year, “and we had a great response , they responded with intrigue and enthusiasm.

Douglas said both publications are already being used by other municipalities.

“It was really exciting to see our content actually used beyond Nelson,” she said, adding that provinces and the federal government may one day regulate embodied carbon as a method of substantially reducing emissions.

“Getting ahead is really good for our construction community,” she said.

Douglas explained that embodied carbon emissions can be calculated before a building is constructed. Using the example of a house with 28 tonnes of embodied carbon, she said her work shows it would take 23 years of operational carbon emissions to equal that 28 tonnes.

“By focusing on high-emitting, high-volume materials, we can really make significant reductions today. Some builders in our community are already doing this. I’m obviously a keener and a nerd about it, but it’s good to know I’m not the only one.

The show guide is available at https://bit.ly/3MdAthL.

At the May 23 meeting, Councilor Jesse Woodward, referencing this work on embodied carbon and a presentation at the same meeting about Nelson’s collaboration with UBC to assess the profitability of promoting e-bikes as a climate solution, said: “I’m in awe that this is happening, at such a refined level, that we have people digging into this. As one city, the impact would be negligible, but if 1,000 cities were doing this kind of work, it’s really powerful.


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