How much of the area inside the LEED boundary must be included?

Hi Lawrence, There are a couple things to consider here: 1) With respect to the area that will be planted with prairie grasses - if this area is equal to or greater than a) 20% of the total site area, or b) 50% of the site area minus the building footprint, you may be eligible to pursue SSc5.1 Protect or Restore Habitat. As long as the prairie is not a monoculture, it should contribute to the credit. 2) With respect to the vegetated, non-irrigated area, there are two ways to treat this: A) Exclude the non-irrigated area. Simply provide a narrative indicating that it is typical in the locale to not irrigate portions of the property, and the irrigation water use calculations have been run to examine only the area that is irrigated, hence why the total area shown in the calculations does not match the area noted in the project information forms. The total area for the base and design case must be the same; OR B) Include the non-irrigated area. If the introduction of the prairie is an approach the team is using to reduce the amount of water used for irrigation, then you can include the area that is not irrigated and assign it a Ks of 0. In the description of the vegetation type, just label it as 'non-irrigated vegetation'. The total area must still be the same for the base and design case, but your design case will have some portion shown that is non-irrigated, while your base case will not. It should be noted, however, that any existing/natural/undisturbed vegetation should be excluded from the calculation altogether. You would just note this area in your narrative.