A multifamily project we are working on has relatively small units - average unit size of 900 square feet. We've found that meeting the 0.23 compartmentalization threshold is more challenging to meet as units get smaller. Because this project has small unit, can we instead meet the Midrise v2010 compartmentalization prerequisite threshold of 0.30?
Revised Ruling (Proposed changes*[]*):
Yes, multifamily buildings whose average unit size is less than 1,200 square feet (110 square meters) and single-family houses with less than 800 square feet (74 square meters) of conditioned floor area may meet the following:
For EQ prerequisite Compartmentalization and EQ prerequisite Environmental tobacco smoke control, demonstrate an allowable maximum leakage of 0.30 cfm50 per square foot of enclosure (i.e., all surfaces enclosing the apartment, including exterior and party walls, floors, and ceiling). **[For multifamily buildings whose average unit size is less than 500 square feet (46 square meters) of conditioned floor area, demonstrate an allowable minimum leakage of 0.40 cfm50 per square foot of enclosure.]**
For Midrise EQ credit Enhanced Compartmentalization, to earn all 3 points, the 0.15 cfm50 per square foot of enclosure area threshold must be met. But partial credit is available, for 1 point, demonstrate maximum leakage of 0.23 cfm50 per square foot of enclosure (i.e., all surfaces enclosing the apartment, including exterior and party walls, floors, and ceiling).
For Homes EQ credit Enhanced Compartmentalization, for 1 point, demonstrate maximum leakage of 0.23 cfm50 per square foot of enclosure (i.e., all surfaces enclosing the apartment, including exterior and party walls, floors, and ceiling).
***[Updated [insert date] to allow multifamily units less than 500 square feet to meet EQp Compartmentalization at a higher threshold.]**
Applicability: Remains the same (v4 Homes, v4 Midrise)