Greenhouse in a Rear Yard?

Q: What are the requirements dictating the construction of a Greenhouse in a Rear Yard?

A: The below is a summary of a DOB Memo by Irving Minkin, dated 4/8/77 outlining the criteria for Greenhouses. I believe this is still in force:

1. Greenhouse & structure to which it is attached shall be non-commercial.
2. Greenhouse may project a maximum of 6' into the required Rear Yard, measured from the exterior face of the building wall.
3. Greenhouse may rest directly upon Grade level or be supported by columns.
4. No offensive dust or odors may be created by such use.
5. The Greenhouse together with its supports, is permanently constructed of non-combustible materials.
6. Glazing is with plain or wire glass.Slow-burning plastic is not permitted. A 'Greenhouse-Type glass constructed rood must be built as part of the enclosure.
7. The Greenhouse floor construction shall be capable of sustaining a minimum Live Load of 75 lbs.
8. The enclosed Greenhouse shall contribute to the Zoning Floor Area of the building.
9. The Greenhouse shall contain operable windows providing light and ventilation. 10% windows required for the combined area of the Greenhouse and any interior room being served by the windows.
10. The depth of the Greenhouse shall not be included in the maximum permitted depth of a room without a window.