Authorities Having Jurisdiction: DC

Some key things to remember:

DC requires 15% (!) of units to be Type A ANSI accessible. This is fraught with different interpretations. 15% of units on the accessible route? 15% of units for the entire building/project? It is only clear that new construction in an elevatored building has 15% HC units, due to the fact that every unit is on an accessible route. Woodson Heights demonstrated that the same agency can have 2 different interpretations of this during the permitting process, and no clear answer.

DCRA website.

DC Building Code Supplement of 2008.

DC Building Code Supplement of 2003 (now defunct, but still enforced for buildings with permit submissions prior to December 2008)

Roof ventilation - different types of roof vents

"Roof jacks" aka shed roof vents for situations where ridge or gable venting is not possible. This assumes that soffit venting is in place; this vent draws air through the higher portion of the roof.

Energy efficient roof designs are starting to look into not ventilating the roof at all and considering the roof membrane as a portion of the insulated building envelope.