Our project involves the renovation of 5 existing historic, residence halls. We were somewhat surprised to find out that student rooms with large existing windows (4\'x6\')with 8\'6" head height, were coming up short of the 2% daylight level using the LEED calculator. So, we composed a daylighting computer model to study the rooms. In the model, there are small areas of each room that do not meet the 2% requirement. In most cases, this area is the doorway entry area adjacent to a closet. Our question is: In modeling this, does 100% of each student room need to meet the 2% factor? (Realizing that the doorway will not be used for critical tasks such as reading or studying.) In other words, can a small percentage of each room fall below the 2% factor as long as the total 2% daylight area totals more than 75% of the total occupied spaces?
The LEED v2.0 Calculator (also usable for v2.1) is designed for simple geometries and provides default data to support a simplified analysis. For a more detailed analysis, a daylight simulation such as the one undertaken is an appropriate means to demonstrate meeting the credit\'s requirements. This credit can be approached so that 100% of each room does not have to meet the 2% daylight factor. In order to do so, the portion of the room with a 2% (or higher) daylight factor would count towards the 75% of all space occupied for critical visual tasks. The portion of the room not meeting the 2% daylight factor would not count towards the 75%. In using the LEED v2.0 Calculator, the two portions of the room (the one meeting the 2% daylight factor and the one not meeting the 2% daylight factor) would be counted as separate spaces. The square footage of all compliant spaces is tallied and then divided over the total square footage of all regularly occupied spaces. If the percentage is greater than 75%, then the building qualifies for this credit. Applicable internationally.