Extensive Green Roof (Sedum)
A lightweight extensive green roof — a shallow growing medium planted with sedum (or a biodiverse/brown-roof mix). Attenuates rainfall, cools the roof, protects the waterproofing and adds habitat. Honest note: the build-up itself (waterproofing, root barrier, drainage, substrate) carries embodied carbon — the benefit is SuDS, biodiversity and roof longevity, not carbon sequestration.
Carbon and evidence
Carbon Sink & Ecosystem Services
A living landscape element — a carbon sink and provider of ecosystem services, not a manufactured product. Its value is measured by sequestration and biodiversity, not embodied carbon, and it must never be netted against a product’s A1–A3.
Carbon Sequestration
Not sequestration-led
The primary value here is biodiversity and/or water function, not carbon storage.
Biodiversity Net Gain
sedum roofs are low; a biodiverse/substrate-varied brown roof scores medium
Source: Defra Biodiversity Metric 4.0
England requires a 10% Biodiversity Net Gain; distinctiveness is one input to the habitat unit calculation.
Water / SuDS
good — retains and slows roof runoff
Source: CIRIA SuDS Manual (C753)
Ecosystem Services
Establishment & Maintenance
the build-up (waterproofing, root barrier, drainage layer, growing medium) has real embodied carbon; sedum stores very little
Read This Honestly
- •Not a carbon sink — value is SuDS, cooling, biodiversity and roof longevity, not sequestration.
- •Biodiverse / brown-roof mixes give more habitat than sedum-only.
Image: Skasnl - groendakmaterialen.nl / Wikimedia Commons · CC BY-SA 4.0
Products in this category
2 products from 2 manufacturers. Ordered by the evidence each record holds, never by commercial standing.
Specification
- Finish
- Sedum / substrate roof
- Service life
- 40 years