Fallout shelters, buildings or structures, or portions thereof constructed, designed, modified, altered, or intended for or devoted to use as a radiation fallout shelter shall meet the following requirements:
(a) Construction shall be of incombustible or Class II materials designed to withstand normally imposed loads and pressures and to provide radiation protection of the equivalent of three feet of earth (three hundred pounds per square foot).
(b) Shelters designed or used for multipurpose use shall meet all the requirements for such other use as well as the requirements of this chapter.
(c) Fallout shelters shall be used for human habitation only when necessary during a period of public emergency and shall be maintained in a condition of readiness for such use.
(d) Entrances shall incorporate a ninety degree change of direction.
(e) The occupant load shall be not less than ten square feet of floor space and eighty-five cubic feet of room volume per person.
(f) Shelters with an occupant load of more than ten shall be provided with two exits located at opposite sides of the shelter.
(g) Exit doors shall be operable from the inside without the use of a key or any special knowledge or effort.
(h) Stairways need not comply with Section 3305 of the Uniform Building Code, as mended, unless the occupant load is fifty or more persons.
(i) Ventilation providing not less than five cubic feet of air per person per minute shall be provided by a hand-operated blower or blowers.
(j) No light or heat source depleting the oxygen supply of the shelter shall be permitted.
(k) Shelters need not comply with the requirements of Chapter 38 of the building code when used for no other purpose than a fallout shelter.
(l) Group fallout shelters may be constructed upon two or more separately owned contiguous parcels of land under the following conditions:
(1) That portion of each contiguous lot encompassing the shelter and its appurtenances together with an access way not less than five feet in width connecting with a public way shall be dedicated as a "group shelter easement" for the sole purpose of locating and constructing an underground fallout shelter for the convenience and use of the property owners of all lands upon which such shelter and its access way is located and further that such shelter shall not be used for any other purpose whatsoever nor used or occupied except when necessary for protection from fallout radiation, blast, thermal or other effects of nuclear weapons.
(2) Such shelter shall be entirely below ground. Mounding of earth, or the entrance structure, vents or other appurtenances shall not be higher than thirty-six inches above the natural level of the ground.
(3) Such shelter shall be open and accessible at all times to the city of Palo Alto police, building and fire departments for inspection purposes.
(4) Construction of the shelter shall comply with subsections (a), (c), (d), (e), (f), (g), (h), (i), (j), and (k) above and with acceptable engineering standards.
(Ord. 2104 (part), 1962: prior code § 34.1001)