The basic idea? The chosen materials and landscape components sequester carbon to balance out the carbon it took to create it, all within five to 20 years. (Five for greener projects like parks, gardens, campuses and mixed-use developments, with up to 20 years for more urban projects.)
The important new development is that they’ve run the numbers: it is possible with reasonable changes to make landscape architecture carbon-positive within these short timeframes and without making everything grass and wood.
As part of a NZGBC project, I managed to introduce permeable paving into some hardscape design and recall how hard it was to make that one simple, invisible change. The sooner these design techniques can become standard practice the better.
It is awesome to see all these new groups jumping up to make their impacts zero-carbon. I’d like to see a more system-level approach someday, but this is great.