# How to find emission factors for recycled concrete aggregate **URL:** \ **Category:** Construction\ **Tags:** concrete\ **Created:** [May 14, 2025, 4:05pm UTC](https://community.carbonleadershipforum.org/t/how-to-find-emission-factors-for-recycled-concrete-aggregate/8897 "2025-05-14T16:05:42Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![candacep](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@candacep](https://community.carbonleadershipforum.org/u/candacep)\ **Post date:** [May 14, 2025, 4:05pm UTC](https://community.carbonleadershipforum.org/t/how-to-find-emission-factors-for-recycled-concrete-aggregate/8897/1 "2025-05-14T16:05:42Z")
Hi everyone, I am trying to learn how to compare the embodied carbon of concrete with natural aggregate vs concrete with onsite recycled aggregate. I found [CarbonStar](https://www.csagroup.org/store/standards-support-tools/environment/carbon-star/), which provides the methodology. But I don’t know where to source the emissions factor for recycled aggregate. Would a custom EPD need to be generated? Probably a silly question but I’m more familiar with the vertical building world where recycling concrete onsite for aggregate isn’t common. I’m hoping the contractors have more context from horizonal infrastructure projects. ---
**Author:** ![Sadie\_Adeline](https://sea1.discourse-cdn.com/flex015/user_avatar/community.carbonleadershipforum.org/sadie_adeline/32/3014_2.png) [@Sadie\_Adeline](https://community.carbonleadershipforum.org/u/Sadie_Adeline)\ **Post date:** [July 11, 2025, 5:57pm UTC](https://community.carbonleadershipforum.org/t/how-to-find-emission-factors-for-recycled-concrete-aggregate/8897/2 "2025-07-11T17:57:40Z")
**“Not a silly question at all - for recycled aggregate, emissions factors can vary widely by location and processing method. If a generic EPD isn’t available, a custom EPD or data from local recyclers might be your best bet. Contractors working on roads or civil projects may definitely have more insight.”**