I have a project, under the current condition, say there are 20% building, 50% of pavement for road and parking, and only 25% left for open space (greenfield) and 5% for wetland (excluding from greenfield for calculation?). Under the proposed condition, a parking garage will be built at one of the existing parking lot.
Since there is only 25% greenfield on site right now, before seeking option #1 or #2, we have to preserve and protect at least 40% of the greenfield, say keeping at least 25% x 40% = 10% preserved and protected. Would you please let me know if my understanding is correct?
If we go for option #2, I understood that the financial support is calculated for $0.40/SF for the entire area within the LEED boundary. This is one-time contribution. Am I right?
If we go for option #1, then we have to restore 30% of 20%+50% (previously disturbed area), in other word, reducing the proposed impervious area to less than 49% of the site. Would you please let me know if my understanding is correct? Of course, we have to meet all the soil criteria.
Calie Gihl
Design EngineerLEEDuser Expert
19 thumbs up
December 17, 2017 - 5:36 pm
Hi John,
I think you're almost on track with your first assumption. You still need to preserve 40% of the greenfield area, regardless of the percentage of the total lot that it occupies. You are right that the area you're preserving will be 10% - but it will be 10% of the TOTAL lot, not just 10% of the greenfield space.
For option 2 - This is correct, it is a one time contribution. Just so you know, there is also an alternative compliance pilot credit available for this option: https://www.usgbc.org/node/5052535?return=/pilotcredits/New-Construction/v4
For option 1 - you need to restore 30% of everything previously disturbed. So, if that 70% is all that was previously disturbed, 30% of that is 21% of your TOTAL Lot. So your total restored area is 21 + 10 = 31% of your total lot.
I think the credit documentation on USGBC.org (https://www.usgbc.org/node/2758192?view=guide&return=#) might help you understand the finer details of this credit as well!