# Materials **URL:** https://community.carbonleadershipforum.org/c/materials/6.md [Latest](https://community.carbonleadershipforum.org/latest.md) · [Categories](https://community.carbonleadershipforum.org/categories.md) · [Tags](https://community.carbonleadershipforum.org/tags.md) --- ## [About the Materials category](https://community.carbonleadershipforum.org/t/about-the-materials-category/31)
**Author:** [@clf-admin](https://community.carbonleadershipforum.org/u/clf-admin)\ **Replies:** 1\ **Last updated:** [February 25, 2020, 12:54pm UTC](https://community.carbonleadershipforum.org/t/about-the-materials-category/31 "2020-02-25T12:54:28Z")
This category applies to topics that relate to reducing the carbon intensity of materials, which are at the heart of embodied carbon in buildings. Although some traditional and emerging materials can offer significant e… --- ## [NRMCA Regional baselines + Type 1L](https://community.carbonleadershipforum.org/t/nrmca-regional-baselines-type-1l/9366)
**Author:** [@Kjell\_Anderson](https://community.carbonleadershipforum.org/u/Kjell_Anderson)\ **Replies:** 1\ **Last updated:** [July 20, 2026, 9:21pm UTC](https://community.carbonleadershipforum.org/t/nrmca-regional-baselines-type-1l/9366 "2026-07-20T21:21:44Z")
Hi - I’m looking at the NRMCA v3.2 regional baselines. When I look at the pages for ‘Benchmark Mix Design’ I can see the average ingredients in each mix. Portland cement, fly ash, slag cement, water, etc. I don’t see a l… --- ## [Site retaining walls (precast vs block)](https://community.carbonleadershipforum.org/t/site-retaining-walls-precast-vs-block/9034)
**Author:** [@aaron.vaden-youmans](https://community.carbonleadershipforum.org/u/aaron.vaden-youmans)\ **Replies:** 4\ **Last updated:** [June 24, 2026, 5:55pm UTC](https://community.carbonleadershipforum.org/t/site-retaining-walls-precast-vs-block/9034 "2026-06-24T17:55:19Z")
Hello Team - Quick Question: A project in Las Vegas requires a number of very long retaining walls integrated into the site. Will we be more successful reducing embodied carbon with a block wall than a precast wall (give… --- ## [PNW Building Material Reuse Working Group April Meeting- A Deconstruction Contractor's Perspective](https://community.carbonleadershipforum.org/t/pnw-building-material-reuse-working-group-april-meeting-a-deconstruction-contractors-perspective/9319)
**Author:** [@JTempleton1](https://community.carbonleadershipforum.org/u/JTempleton1)\ **Replies:** 0\ **Last updated:** [April 28, 2026, 5:53pm UTC](https://community.carbonleadershipforum.org/t/pnw-building-material-reuse-working-group-april-meeting-a-deconstruction-contractors-perspective/9319 "2026-04-28T17:53:40Z")
Are you excited about building material reuse? Have you ever wondered about the deconstruction process? Been curious about what materials are the most viable to selectively deconstruct and reuse? Please join us at our m… --- ## [Specification Requirements for Multi-Attribute products in LEEDv5 MRc4 - Building Product Selection and Procurement](https://community.carbonleadershipforum.org/t/specification-requirements-for-multi-attribute-products-in-leedv5-mrc4-building-product-selection-and-procurement/9292)
**Author:** [@andrewratzke](https://community.carbonleadershipforum.org/u/andrewratzke)\ **Replies:** 0\ **Last updated:** [March 10, 2026, 6:23pm UTC](https://community.carbonleadershipforum.org/t/specification-requirements-for-multi-attribute-products-in-leedv5-mrc4-building-product-selection-and-procurement/9292 "2026-03-10T18:23:10Z")
Hi all - How are teams thinking about specification language/requesting documentation for the new LEEDv5 MRc4 as it relates to non-structural composite wood products? Given there are so many different ways to earn points… --- ## [CLF Seattle : Low carbon concrete session](https://community.carbonleadershipforum.org/t/clf-seattle-low-carbon-concrete-session/9269)
**Author:** [@Yamini\_Bhatt](https://community.carbonleadershipforum.org/u/Yamini_Bhatt)\ **Replies:** 0\ **Last updated:** [February 13, 2026, 9:44pm UTC](https://community.carbonleadershipforum.org/t/clf-seattle-low-carbon-concrete-session/9269 "2026-02-13T21:44:31Z")
Hello Seattle CLF Hub members! Please Join us online this 2026-02-18T20:00:00Z (UTC) for a Carbon Leadership Forum– SEA x PDX Hub presentation on “Implementation of low embodied carbon concrete specifications” Meeting … --- ## [Asphalt Decarbonization](https://community.carbonleadershipforum.org/t/asphalt-decarbonization/9254)
**Author:** [@jschwartzhoff](https://community.carbonleadershipforum.org/u/jschwartzhoff)\ **Replies:** 3\ **Last updated:** [February 2, 2026, 2:12pm UTC](https://community.carbonleadershipforum.org/t/asphalt-decarbonization/9254 "2026-02-02T14:12:25Z")
Does anyone have any recent guidance on asphalt reduction best practices? I’ve been doing a deep dive on the latest NAPA, US DOT, CLF resources, and they point to recycled asphalt product (RAP), recycled asphalt shingle… --- ## [MN Adopts Hempcrete and Strawbale in Residential Building Codes](https://community.carbonleadershipforum.org/t/mn-adopts-hempcrete-and-strawbale-in-residential-building-codes/9255)
**Author:** [@HempcreteQueen](https://community.carbonleadershipforum.org/u/HempcreteQueen)\ **Replies:** 0\ **Last updated:** [January 28, 2026, 12:35am UTC](https://community.carbonleadershipforum.org/t/mn-adopts-hempcrete-and-strawbale-in-residential-building-codes/9255 "2026-01-28T00:35:38Z")
Minnesota is the first US state on the path to adopting the newest official residential building codes featuring plant-based building materials after a July 15, 2025 hearing in St. Paul. The state’s Technical Advisory G… --- ## [New updates to Natural Building 2027 IRC Appendices](https://community.carbonleadershipforum.org/t/new-updates-to-natural-building-2027-irc-appendices/9218)
**Author:** [@HempcreteQueen](https://community.carbonleadershipforum.org/u/HempcreteQueen)\ **Replies:** 0\ **Last updated:** [December 2, 2025, 2:41am UTC](https://community.carbonleadershipforum.org/t/new-updates-to-natural-building-2027-irc-appendices/9218 "2025-12-02T02:41:58Z")
By Martin Hammer Natural Building code experts received two approvals and one thumbs-down for appendix updates submitted for approval at the International Residential Code Committee Week in Cleveland last month. Berkel… --- ## [Hemp Building Materials Hold Their Own at Greenbuild in Los Angeles](https://community.carbonleadershipforum.org/t/hemp-building-materials-hold-their-own-at-greenbuild-in-los-angeles/9209)
**Author:** [@HempcreteQueen](https://community.carbonleadershipforum.org/u/HempcreteQueen)\ **Replies:** 0\ **Last updated:** [November 11, 2025, 1:57am UTC](https://community.carbonleadershipforum.org/t/hemp-building-materials-hold-their-own-at-greenbuild-in-los-angeles/9209 "2025-11-11T01:57:11Z")
At this year’s Greenbuild Conference and Expo, held Nov. 4–7 in Los Angeles, bio-based building materials took the spotlight — both on the show floor and in one of the conference’s most crowded sessions. As sustainabilit… --- ## [Six Predictions for 2025 in the Hemp Building Industry](https://community.carbonleadershipforum.org/t/six-predictions-for-2025-in-the-hemp-building-industry/8516)
**Author:** [@HempcreteQueen](https://community.carbonleadershipforum.org/u/HempcreteQueen)\ **Replies:** 1\ **Last updated:** [October 29, 2025, 3:20pm UTC](https://community.carbonleadershipforum.org/t/six-predictions-for-2025-in-the-hemp-building-industry/8516 "2025-10-29T15:20:37Z")
We’re sticking out our neck at HempBuild Mag and trying to predict what will happen in the wonderful and confusing hemp building industry in the new year. What’s ahead for 2025? We’re predicting big projects, architect … --- ## [Fabric Ducts vs Galvanized](https://community.carbonleadershipforum.org/t/fabric-ducts-vs-galvanized/9179)
**Author:** [@stan](https://community.carbonleadershipforum.org/u/stan)\ **Replies:** 2\ **Last updated:** [October 14, 2025, 7:48pm UTC](https://community.carbonleadershipforum.org/t/fabric-ducts-vs-galvanized/9179 "2025-10-14T19:48:14Z")
Has anyone looked at embodied carbon of fabric vs galvanized duct. Im super new to EPD’s and a little confused. My understanding is that the EPD’s report per unit weight of product so its a bit tricky to compare 1kg of f… --- ## [Type 1L cement - causing higher conductivity?](https://community.carbonleadershipforum.org/t/type-1l-cement-causing-higher-conductivity/9124)
**Author:** [@JLee\_SF](https://community.carbonleadershipforum.org/u/JLee_SF)\ **Replies:** 1\ **Last updated:** [September 5, 2025, 1:27am UTC](https://community.carbonleadershipforum.org/t/type-1l-cement-causing-higher-conductivity/9124 "2025-09-05T01:27:08Z")
We had a concrete slab that had some static flooring installed. The install passed as a conductive floor but failed as a dissipative floor. The mix contains type 1L cement and it was discussed that the increased amount o… --- ## [Rebar Specifications](https://community.carbonleadershipforum.org/t/rebar-specifications/9112)
**Author:** [@aaron.vaden-youmans](https://community.carbonleadershipforum.org/u/aaron.vaden-youmans)\ **Replies:** 2\ **Last updated:** [August 26, 2025, 5:44pm UTC](https://community.carbonleadershipforum.org/t/rebar-specifications/9112 "2025-08-26T17:44:11Z")
Quick Question: I have a large project in SoCal that includes the following rebar spec language: “Average recycled steel content such that the post-consumer recycled content plus one-half of the pre-consumer recycled co… --- ## [Concrete Max GWP Allowed in SoCal (Quick Check)](https://community.carbonleadershipforum.org/t/concrete-max-gwp-allowed-in-socal-quick-check/9035)
**Author:** [@aaron.vaden-youmans](https://community.carbonleadershipforum.org/u/aaron.vaden-youmans)\ **Replies:** 9\ **Last updated:** [July 29, 2025, 6:00pm UTC](https://community.carbonleadershipforum.org/t/concrete-max-gwp-allowed-in-socal-quick-check/9035 "2025-07-29T18:00:37Z")
Is there a quick way to learn if these values are the best I can do on a SoCal project without adding cost to a project?: --- ## [Mass Timber / CLT Resilient Floor Alternative to Concrete Topping Slabs](https://community.carbonleadershipforum.org/t/mass-timber-clt-resilient-floor-alternative-to-concrete-topping-slabs/5113)
**Author:** [@aaron.vaden-youmans](https://community.carbonleadershipforum.org/u/aaron.vaden-youmans)\ **Replies:** 8\ **Last updated:** [June 20, 2025, 5:37pm UTC](https://community.carbonleadershipforum.org/t/mass-timber-clt-resilient-floor-alternative-to-concrete-topping-slabs/5113 "2025-06-20T17:37:49Z")
Hello All - Can anybody suggest alternatives to lightweight concrete topping slabs for mass timber/CLT resilient floors? I will specify a raised floor system where possible for this large mixed-use technology campus, bu… --- ## [Impact of cold form shear wall sheathing (plywood vs steel sheet)](https://community.carbonleadershipforum.org/t/impact-of-cold-form-shear-wall-sheathing-plywood-vs-steel-sheet/8950)
**Author:** [@Oliviapax](https://community.carbonleadershipforum.org/u/Oliviapax)\ **Replies:** 1\ **Last updated:** [June 18, 2025, 7:09pm UTC](https://community.carbonleadershipforum.org/t/impact-of-cold-form-shear-wall-sheathing-plywood-vs-steel-sheet/8950 "2025-06-18T19:09:47Z")
I’m beginning the structural design for a building with cold form walls and shear walls. For it, the basis of design has assumed steel sheathing at the shear walls. I know that a 1:1 comparison of wood structural panel … --- ## [Embodied Carbon in Piping Materials](https://community.carbonleadershipforum.org/t/embodied-carbon-in-piping-materials/8789)
**Author:** [@Jackand](https://community.carbonleadershipforum.org/u/Jackand)\ **Replies:** 3\ **Last updated:** [May 27, 2025, 3:44pm UTC](https://community.carbonleadershipforum.org/t/embodied-carbon-in-piping-materials/8789 "2025-05-27T15:44:13Z")
Hi everyone, My jurisdiction is interested in incorporating sustainability considerations into our selection of conveyance piping materials (Ductile Iron, PVC, HDPE, Clay etc.). There are many variables that affect the … --- ## [Benchmarking Concrete for LEED](https://community.carbonleadershipforum.org/t/benchmarking-concrete-for-leed/1563)
**Author:** [@prateek.jain](https://community.carbonleadershipforum.org/u/prateek.jain)\ **Replies:** 12\ **Last updated:** [May 5, 2025, 6:17pm UTC](https://community.carbonleadershipforum.org/t/benchmarking-concrete-for-leed/1563 "2025-05-05T18:17:43Z")
Hi all, Curious to know how folks have been creating baselines for concrete, against which you calculation the impact reductions in your project’s concrete mixes. The NRMCA 2016 and 2019 benchmarks are great resources, … --- ## [Accounting For EC During B1-B7 Use Stage](https://community.carbonleadershipforum.org/t/accounting-for-ec-during-b1-b7-use-stage/8831)
**Author:** [@bbornhurst](https://community.carbonleadershipforum.org/u/bbornhurst)\ **Replies:** 0\ **Last updated:** [April 24, 2025, 3:40pm UTC](https://community.carbonleadershipforum.org/t/accounting-for-ec-during-b1-b7-use-stage/8831 "2025-04-24T15:40:23Z")
I have been randomly polling peeps on where we account for EC within the LCA stages for actual building material replacement that has a life expectancy of less than 60 years? The most common response seems to be, B1-B7 … --- ## [EPDs for masonry mortar/grout?](https://community.carbonleadershipforum.org/t/epds-for-masonry-mortar-grout/8752)
**Author:** [@jshiman](https://community.carbonleadershipforum.org/u/jshiman)\ **Replies:** 3\ **Last updated:** [April 20, 2025, 10:46pm UTC](https://community.carbonleadershipforum.org/t/epds-for-masonry-mortar-grout/8752 "2025-04-20T22:46:35Z")
I’m trying to track down some embodied carbon information on grout & mortar for masonry (brick & CMU) applications. I’m not finding anything in any of the usual locations (EC3, CLF baselines, etc) but hoping I’m just not… --- ## [Low Embodied Carbon CMU (North Atlantic Region)](https://community.carbonleadershipforum.org/t/low-embodied-carbon-cmu-north-atlantic-region/8804)
**Author:** [@aaron.vaden-youmans](https://community.carbonleadershipforum.org/u/aaron.vaden-youmans)\ **Replies:** 4\ **Last updated:** [April 17, 2025, 7:10pm UTC](https://community.carbonleadershipforum.org/t/low-embodied-carbon-cmu-north-atlantic-region/8804 "2025-04-17T19:10:36Z")
Hello CLF Team - What is the lowest embodied carbon CMU block available in the North Atlantic region with and without a cost premium? This is for a NYC project. Thank you (again), Aaron --- ## [Actual Volume of material for modeled masses](https://community.carbonleadershipforum.org/t/actual-volume-of-material-for-modeled-masses/8780)
**Author:** [@LO\_Diane](https://community.carbonleadershipforum.org/u/LO_Diane)\ **Replies:** 2\ **Last updated:** [April 7, 2025, 7:20pm UTC](https://community.carbonleadershipforum.org/t/actual-volume-of-material-for-modeled-masses/8780 "2025-04-07T19:20:09Z")
I am trying to do LCA on revit projects and our walls, floor and roofs are modeled as masses, the correct thickness, but it’s a solid mass. So when i’m running a material takeoff of the model it has a lot more material t… --- ## [Sustainable Material Sourcing in Portland Oregon](https://community.carbonleadershipforum.org/t/sustainable-material-sourcing-in-portland-oregon/8781)
**Author:** [@joannacatley](https://community.carbonleadershipforum.org/u/joannacatley)\ **Replies:** 0\ **Last updated:** [April 2, 2025, 5:38pm UTC](https://community.carbonleadershipforum.org/t/sustainable-material-sourcing-in-portland-oregon/8781 "2025-04-02T17:38:26Z")
Hi there, I am new to the Portland OR Architecture industry. I am in charge of Lunch and Learns at my firm and I am looking for local/regional companies with a sustainability focus to come present to my team, providing C… --- ## [Reduction requirements in bidding](https://community.carbonleadershipforum.org/t/reduction-requirements-in-bidding/8766)
**Author:** [@scott\_waddell](https://community.carbonleadershipforum.org/u/scott_waddell)\ **Replies:** 1\ **Last updated:** [March 30, 2025, 2:19pm UTC](https://community.carbonleadershipforum.org/t/reduction-requirements-in-bidding/8766 "2025-03-30T14:19:15Z")
My firm has focused on specifying GWP limits by individual concrete strengths, steel types, and other materials, but I see the many advantages of instead setting minimum GWP reductions for the project, based on quantity,… --- ## [MA Hempcrete Duplex Development Ready to Welcome Residents](https://community.carbonleadershipforum.org/t/ma-hempcrete-duplex-development-ready-to-welcome-residents/8618)
**Author:** [@HempcreteQueen](https://community.carbonleadershipforum.org/u/HempcreteQueen)\ **Replies:** 0\ **Last updated:** [February 11, 2025, 5:05pm UTC](https://community.carbonleadershipforum.org/t/ma-hempcrete-duplex-development-ready-to-welcome-residents/8618 "2025-02-11T17:05:20Z")
The largest hemp project in the United States consisting of 12 duplex units in Newburyport, MA will open to residents this month. Builder David Hall and architect Keith Moskow of Hall and Moskow Corporation have been wor… --- ## [Best Practice for Low Embodied Carbon Decorative Concrete Exterior Paving](https://community.carbonleadershipforum.org/t/best-practice-for-low-embodied-carbon-decorative-concrete-exterior-paving/8607)
**Author:** [@aaron.vaden-youmans](https://community.carbonleadershipforum.org/u/aaron.vaden-youmans)\ **Replies:** 1\ **Last updated:** [February 7, 2025, 3:03pm UTC](https://community.carbonleadershipforum.org/t/best-practice-for-low-embodied-carbon-decorative-concrete-exterior-paving/8607 "2025-02-07T15:03:34Z")
Hello Team - Could someone point me to current best practice guidance for specifying low embodied carbon decorative concrete exterior paving? I am also interested in relevant products that support the low-embodied concre… --- ## [Carbon math fights - biogenic and fossil and LUC!](https://community.carbonleadershipforum.org/t/carbon-math-fights-biogenic-and-fossil-and-luc/8473)
**Author:** [@stuart.s](https://community.carbonleadershipforum.org/u/stuart.s)\ **Replies:** 2\ **Last updated:** [January 3, 2025, 6:21am UTC](https://community.carbonleadershipforum.org/t/carbon-math-fights-biogenic-and-fossil-and-luc/8473 "2025-01-03T06:21:17Z")
I love wood, but are we subtracting biogenic GWP from fossil GWP when presenting climate impacts? Practice seems to be maturing fast, helped by EN 15804 +A2. But I’ve become a bit cynical of long-term biogenic landfill s… --- ## [Embodied Carbon of Shading v MEP](https://community.carbonleadershipforum.org/t/embodied-carbon-of-shading-v-mep/8401)
**Author:** [@Kjell\_Anderson](https://community.carbonleadershipforum.org/u/Kjell_Anderson)\ **Replies:** 4\ **Last updated:** [December 12, 2024, 6:39pm UTC](https://community.carbonleadershipforum.org/t/embodied-carbon-of-shading-v-mep/8401 "2024-12-12T18:39:37Z")
Shading of fenestration is often made of metals, including additional structure, and thus have high embodied carbon. However, shading can reduce the size, cost, and embodied carbon of HVAC systems and supporting electric… --- ## [A few day left to apply to One Click LCA's Low-Carbon Manufacturing Awards](https://community.carbonleadershipforum.org/t/a-few-day-left-to-apply-to-one-click-lcas-low-carbon-manufacturing-awards/8409)
**Author:** [@Mel](https://community.carbonleadershipforum.org/u/Mel)\ **Replies:** 0\ **Last updated:** [November 28, 2024, 2:30pm UTC](https://community.carbonleadershipforum.org/t/a-few-day-left-to-apply-to-one-click-lcas-low-carbon-manufacturing-awards/8409 "2024-11-28T14:30:23Z")
Manufacturers of building materials such as: cement & concrete, metals & alloys, wood & fiber, ceramics & glass, insulation, and MEP have a few more days to apply to One Click LCA’s Low-Carbon Manufacturing Awards. Winne… [Next page](https://community.carbonleadershipforum.org/c/materials/6.md?page=1)