For part (a), more information is needed for the open house requirement. Specifically: Is a weekend defined as Saturday and Sunday, for a total of 32 hours over 4 weekends? Can a home be open for 8 hours on either Saturday or Sunday and still have this count toward the total - i.e. can a project earn this with 32 hours over 5 or 6 weekends? Can weekdays count toward the total number of hours?
The original intent of this requirement was to have an open house on Saturday and Sunday for four weekends. However, the requirement can alternatively be met by having at least 32 hours of open house, subject to the following two conditions (in addition to those already in the credit): 1) the home must be open in blocks of at least 4 hours; 2) open house hours must be on Saturdays, Sundays, holidays, or weekday evenings.
Updated 10/1/13 for rating system applicability.