BUILDING, REMODELING OR ENLARGING YOUR HOME
New single family residence or commercial facility
Building additions which add square footage to conditioned space of a
Building remodels that either do not add square footage to conditioned
space of a pre-existing structure or involve accessory structures such as
garage, workshop, storage buildings
If your parcel is within the jurisdiction of the Stinson Beach County Water District
(SBCWD), the Application for Building Permit must be reviewed and endorsed by District
staff. Please review the following to avoid unnecessary delays to your project.
Prior to release of the Application for Building Permit, the following requirements must be
New single family residence or commercial facility:
The property owner must obtain a construction and discharge permit for an onsite system
from the Stinson Beach County Water District. Contact the District for the appropriate
forms and fee schedule.
Building additions which add square footage to the conditioned space of a pre-
The District defines this a new construction (see definition below) and requires that the
onsite wastewater disposal system meet current
District Code (SBCWD Ordinance WW2000-01).
Variances to this provision can be applied for if the current system is an engineered
system, is in excellent operating condition, and if the residence will not exceed the square
footage limitations defined by the size of the current system. The variance procedure is
outlined in Chapter 4.13
and requires San Francisco Regional Water Quality Control Board
review and SBCWD Board approval. If a variance is granted, the applicant must
demonstrate that the system is functioning as designed.
4.03.252 New Construction.
"New construction" shall mean the construction
of a new building, or the construction of an addition to, the alteration of, or
the remodeling of an existing building which results in an increase in
habitable space or other heated or otherwise conditioned space within the
building. Further, the construction of any new structure within a setback from
a component of a wastewater disposal system required at the time the
system was installed shall be deemed to be "new construction."
Building remodels that either do not add square footage to the conditioned space
of a pre-existing structure or involve accessory structures such as - garage,
workshop, storage buildings:
The District defines this as alterations and additions that do not constitute new
construction (see definition below) and requires that the septic system must be found to
be adequate for the residence, to be in good working condition, and not jeopardize public
health or safety. An evaluation of the onsite wastewater disposal system will be required.
This evaluation must be conducted by a qualified professional, usually a civil engineer or
registered environmental health specialist.
4.01.410 Alterations and Additions to Buildings.
Whenever any person makes application to the County of Marin for a building permit
for the purpose of making any alterations to, or enlargement of any structure which meets
the definition of "New Construction" as set forth in
said applicant must demonstrate that the existing septic system meets the requirement set forth in this
If District staff is required to go to the county offices for sign-off of plans, a Plan Check fee
will be appended to the applicants next water bill (this sign-off fee is included in the
construction permit fee).
An applicant may be exempt from this requirement if s/he can demonstrate that there is
currently a septic on the subject property that substantially complies with this code, that
Determination of whether or not a system substantially complies with this code is within
the joint discretion of the District Engineer and the General Manager.
- An engineered gravity flow system in an area of appropriate percolation
rate and ground water depth for such a system; or
- A sand filtration system that incorporates timed dosing and provides a
means to purge all laterals.