14-1014 v2.X Distances to Operable Windows and Daylight


Our project contains a Trades Electrical Lab (see attached) that faces west and has daylight through clerestory windows. The features of the current space include the following: - The space has a long tool crib on the west side for tool storage. The tool crib is located where it is in order to allow access from all 3 labs to a single tool crib – necessary for functional efficiency. - The north and south walls of the lab will house full height equipment which is required for lab functions and incorporating eye level windows would be difficult without compromising the functionality of the spaces 


A row of clerestory windows are located on the west and south side specifically:o lab T105 has clerestory glazing on the west wall and a full height window on the west wallo lab T103 has clerestory glazing on the west wallo lab T101 has clerestory glazing on the west & south walls and a full height window on the west wall - The clerestory glazing is continuous on the elevations you have noted (including above the tool crib on the west elevation) - There are also 4 light tubes skylights in each lab - The entrance doors to the labs at the east end have full height glazing and allow views out to the daylit atrium space and main entrance areaWould the inclusion of the clerestory windows along this space be viewed as meeting the intent for access to daylight – or is a direct line of sight required to meet the daylighting intent?This is a unique program and as such, requires a classroom layout which would exceed the maximum distances to operable windows and reconfiguration of the desks is not possible.


Clerestory windows can meet the need for daylight but not the view requirement established in the LBC Dialogue Post entitled 'Window Requirements' on November 8, 2008 


1. There shall be at least one window-wall in each occupied space.

2. Window-walls are defined as exterior walls that contain at least 10% glazing area.

3. A minimum of 5% of this glazing must be direct view windows, placed such that the sill(s) is no higher than 5 feet above the finished floor.

4. There is no set maximum glass area, since the project will be limited by the demands of the Energy Petal. Please note that a component of the audit process will include daylight measurements. We encourage project teams to take into account the acceptable range for daylight factors based on the function of the space.The project team must include at least one small view window in each lab to comply with these requirements. The full height windows in labs T101 & T105 may be sufficient to meet the view requirement for those spaces. Views to the outside through doors can meet the view requirement, but views to an atrium cannot. The team must also ensure each space has operable openings (typically windows) to meet the operable window requirement.

Post ID 2041

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