California Code of Regulations › Title 25 - Housing and Community Development › Division 1 - Housing and Community Development › Chapter 2 - Mobilehome Parks and Installations › Article 7 - MH-Unit and Commercial Modular Installations and Facilities › Section 1333 - Foundation Systems

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a)
				  Pursuant to Health and Safety Code section 18551, the requirements for MH-unit
				  and commercial modular foundation systems are applicable throughout the
				  state.
(b) The foundation system
				  and the connection of a MH-unit to the foundation system shall be designed to
				  withstand the vertical and lateral forces due to dead load, roof and floor live
				  loads, wind and seismic loads in accordance with the provisions of the
				  California Residential Code and local soil conditions. The roof live load, wind
				  and seismic loads as established for dwellings within specific local areas
				  shall apply.
(c) The foundation
				  system and the connection of a commercial modular to the foundation system
				  shall be designed to withstand the vertical and lateral forces due to dead
				  load, roof and floor live loads, wind and seismic loads in accordance with the
				  provisions of the California Building Code and local soil conditions. The roof
				  live load, wind and seismic loads as established for permanent buildings within
				  specific local areas shall apply.
(d) The vertical and lateral load resisting
				  elements shall be sized and located to resist the loads specified in the
				  manufacturer's installation instructions. The manufacturer's installation
				  instructions shall become a part of the foundation system plans. In the absence
				  of the manufacturer's installation instructions, plans and specifications
				  signed by an architect or engineer covering the installation of an individual
				  MH-unit or commercial modular shall be provided to the enforcement
				  agency.
(e) The foundation system
				  and the connection of the MH-unit or commercial modular to the foundation
				  system shall be capable of withstanding the vertical and lateral loads shown in
				  the manufacturer's installation instructions, or plans and specifications
				  signed by an architect or engineer, including locations where there are
				  concentrated loads.
(f) When an
				  MH-unit or commercial modular is installed on a foundation system, a foundation
				  system plan shall be provided to the enforcement agency. The manufacturer may
				  provide a foundation system plan in its installation instructions, or a
				  foundation system plan may accompany the installation instructions. Foundation
				  systems may be approved by the enforcement agency or the department. Foundation
				  systems approved by the department shall be accepted by every enforcement
				  agency as approved for the purpose of obtaining a construction permit when the
				  design loads and conditions are consistent for the locality. The department
				  shall require that foundation system plans and supporting data be signed by an
				  architect or engineer.
(g) Local
				  enforcement agencies shall not require the original signature or stamp of the
				  architect or engineer on a foundation plan approved by the
				  department.
(h) Foundations for
				  cabanas, porches, and stairways which are accessory to MH-units on foundation
				  systems and foundations for building components shall be subject to approval of
				  the enforcement agency. Porches and stairways which are accessory to commercial
				  modulars on a foundation system shall be subject to approval of the enforcement
				  agency.
(i) When it is necessary
				  for the department to approve plans or to make investigations of complaints
				  relating to foundation system plans, fees shall be paid in accordance with
				  section 1020.9 of article 1.
(j) A
				  standard plan approval may be obtained from the department for a plan for
				  MH-unit or commercial modular foundation systems. The requirements for
				  obtaining a standard plan approval are contained in section 1020.9 of article
				  1.
(k) Multifamily manufactured
				  homes consisting of three (3) or more dwelling units shall be installed on a
				  foundation system pursuant to Health and Safety Code section 18551(a) or
				  (b).
(l) In flood hazard areas,
				  foundation systems must be capable of resisting loads associated with flood and
				  wind events or combined wind and flood events, and homes must be anchored to
				  prevent floatation, collapse, or lateral movement.
(1) The foundation installation instructions
				  must indicate whether:
(A) The foundation
				  specifications have been designed for flood-resistant considerations, and, if
				  so, the conditions of applicability for velocities, depths, or wave action;
				  or
(B) The foundation is not
				  designed to address flood loads.