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Sunroom Requirements

Requirements for the addition of a passive solar sunroom (includes greenhouse, solarium or similar room), will depend on how the room is integrated with the dwelling unit; there are two types:

Type 1 A room which has permanent, unobstructed openings (e.g., full openings without doors or windows) shall be subject to all applicable building code provisions for that occupancy. It will be considered a conditioned space and will be subject to the energy conservation standards and building code requirements in effect at the time of permit application.

Type 2 A passive solar sunroom (includes greenhouse, solarium or similar room), with a separating common wall attached to an R occupancy, shall be classified in the same R occupancy. However, not being an integrated part of the dwelling unit, it is not required to be conditioned space.

As a separate space, all the following provisions shall apply:

  1. A separation common wall must be maintained between the sunroom and the dwelling unit. Operable or non-operable openings (e.g., windows, doors) are allowed.

  2. The sunroom is considered part of the allowable floor area of Table 5, California Building Code, for R-1 or R-3 occupancies.

  3. The roof of the sunroom shall have glazed openings equal to a minimum of 25% of the floor area.
    • Exception - Roof openings may be reduced or omitted, provided that the required area is added to the exterior wall provision of 4.

  4. The glazing of exterior walls of the sunroom shall be a minimum of 65% of the longest wall or 50% of all exterior walls of the added space, whichever is greater.

  5. There shall be adequate roof vents or a mechanical ventilation system in the sunroom. Operable windows, preferably above the plate line, may satisfy this requirement.

  6. The sunroom shall not be mechanically heated or air conditioned. Therefore, the residential energy conservation standards do not apply to that space; however, the separation common wall between the sunroom and the dwelling must be in compliance with the California energy standards (i.e., insulate as necessary).

 The following general requirements shall also apply to sunroom meeting items 1 through 6 above:

  1. Where there are openings between the added space and the dwelling unit attic or crawl space for the purpose of air circulation, smoke-activated fire dampers are required.

  2. The sunroom must be constructed per the California Building Code requirements for the adjoining R-occupancy. The structural design requirements will be those in effect at the time of permit application.