Architecture and building industry stories, news, and opinion from San Francisco based architecture design firm, Kwan Design Architects.

Accessory Dwelling Units

ADU, Accessory Dwelling Unit or JADU, Junior Accessory Dwelling Unit is a way to provide additional housing on the same lot. Its intention is to provide affordable housing options for renters, family members, the elderly, or caregivers. It can also help 1st time buyers to increase income to afford a new home. The following are some key points on ADU regulations:

Review period – An application for ADU or JADU for lots with a single-family dwelling shall be deemed approved, or denied, within 60 days from a completed application. The prior regulation was 120 days.
In San Francisco, if the ADU requires an expansion, neighbors within 150 feet radius and neighborhood groups will be notified for a 30-day public review period. During the 30-day period, a discretionary review process will apply.

Number of ADU allow – Under state law, you can provide (1) ADU and (1) JADU per lot, within the proposed or existing single-family dwelling, if certain conditions are met. For multi-family buildings, state law allows up to 25% of the unit count;

In San Francisco, if (4) or less legal dwelling units are on a lot, only (1) ADU is allowed. If (5) or more legal dwelling units are on a lot, then an unlimited number of ADUs are permitted under S.F. Planning Code. Then, the determination on the number of ADUs will depend on the S.F. Building Code for the abilities to provide natural light, ventilation, and two exits.

Size of the ADU – Under state law, the maximum size of a detached ADU is 1200 sq.ft. for more than one bedroom; local city requirements may vary. For example, the City of Millbrae is 1000 sq.ft. maximum for a detached ADU of more than one bedroom;

Size of the JADU – Under state law, the maximum size of a JADU within the primary dwelling is 500 sq.ft.; local city requirements may vary.

Density Limit – Adding an ADU does not change the allowable density limit of the lot.

Short-term Rentals – ADU cannot be used as short-term rentals.

Owner occupancy requirement – Owner occupancy is not required on ADUs until 2025, which means both the primary dwelling and the ADU can be rented.

For JADUs, owner occupancy is required at the primary dwelling or the JADU.

Rent Controlled – ADUs need to provide affordable rent to very low, low, or moderate-income households.

The information provided is for general reference; Every site has unique challenges, we have the training and experience to help you decide if an ADU makes sense for you from a cost, benefit & lifestyle point-of-view. If you think an ADU makes sense, we can help you to explore design options.

Americans with Disability Act

San Francisco now has a mandatory program to make all commercial business entrance accessible for wheelchair.  In 2016, Ordinance No. 51-16 was passed which requires existing buildings with a place of “public accommodation” to have all primary entrances accessible for people with disabilities.  Click here for more information and we can help you to comply with this requirement.

If you want to renovate an existing commercial space, most likely you will be obligated by the “California Building Code” and the “Americans with Disability Act” (ADA) which is a civil rights law to upgrade your accessibility features such as handicapped parking, main entry, the “Path of Travel” from main entry to the “Area of Primary Function” of the space.  As a building owner or tenant, you have been obligated to do so since 1990 when the “Americans with Disabilities Act” has been in effect.  Most commercial and civic buildings are affected by this federal law in some form or another. Continue reading Americans with Disability Act

PLANTS & FENCES

The following are general guideline regarding fences and planting in San Francisco properties.

San Francisco regulations on fences are based on the location of the fences on the property and required yards and setbacks.  All San Francisco residential districts have rear yard requirements and some districts have side yard and front setback requirements.  Some San Francisco commercial districts have rear yard requirement and in any commercial, industrial or mixed use district have residential use at the first story.  Continue reading PLANTS & FENCES

San Francisco projects without public notifications

Many projects in San Francisco require public notifications which include demolition, new construction, change in use, exterior alteration or building expansions in residential and some commercial zone areas but there are some exceptions as indicated below.

DORMERS:

Dormers can be added to the attic to create additional usable space without public notifications under the following conditions.
(1) The dormer and all other roof features combined area is less than 20% of the roof area.
(2) The maximum plan dimension of the dormer is 8 feet by 8 feet and setback minimum 3 feet from the side property line.
(3) The dormer setback 10 feet from the front building wall.
(4) The dormer cannot be higher than the peak of the roof.

LIGHWELLS INFILL:

When the lightwell at the property line is against your neighbor’s wall and the lightwell is not visible from any offsite location, and the lightwell is not higher than 10 feet above the neighbor’s ground, then the lightwell infill can be approve without public notification. The Planning Department will need a set of reduced drawings signed by the adjacent owner or tenant. If the proposed lightwell infill is visible from any off-site location, then the public notification is required.

ADDITION BELOW:

When you have a floor supported by columns and the open space below does not exceed one story or twelve feet, you can enclose the open space below without public notifications assuming that the floor above is legal.

DECKS:

An open deck can be built without notifications in RH and RM districts under the following conditions:
(1) The deck does not encroach into the required rear yard.
(2) When the deck is less than 10 feet above ground.
(3) If the building code requires a one hour fire wall, then the one hour fire wall needs to be less than 10 feet in height for the deck or stair leading to the deck.

STAIR REPLACEMENT:

Older building may have the Building Code required egress stair located in the required open space. If the replacement stair is within the same footprint and height of the old stair or minimum required by the current Building Code, then the replacement stair can be exempt from notification. The exemption does not apply to new fire wall when the original stair did not have a fire wall, unless the entire firewall is located next to a blank wall of the adjacent neighbor.

The above 5 exceptions summarizes most but not all the rules, for a complete list of rules and regulations please see San Francisco Planning Department Zoning Administrator Bulletin Number 4.

Urban Landscape, San Francisco, California

Nihonmachi Terrace is a high density Japanese senior housing complex in San Francisco Japan Center. The existing courtyard consisted of a lawn and a few trees that provided open space for the tenants and visitors. Kwan Design Architect (in association with Robert La Rocca Landscape Architect) revitalizes the courtyard in response to Japanese garden design principals, natural features and sustainable design solutions. The new courtyard included rock garden with raked gravel, pathways and wooden bridges over a dry creek, plants indigenous to the mountains, water scriptural feature, community vegetable garden, windbreak elements and gathering opportunities.

The Clarendon house, San Francisco, California

The Clarendon house is a 25 foot wide zero lot line property situated on the northern slope of Twin Peaks. The back of the house slopes down and has views from Golden Gate Bridge to downtown and the Bay Bridge. In an effort to preserve these views for the neighboring properties, the expansion was created below the existing house. The program required a 3 bedroom house with large living areas and contemporary style.

The design process was not the “traditional project delivery process” where the owner hires an architect to prepare drawings, then the owner hires a general contractor to bid and build the project. The traditional process creates communication problems and has higher chance of cost increase during construction. In the “traditional project delivery process”, the architect and contractor boundaries are more restricted.

Clarendon was designed under an “integrated project delivery process” where the owner requires a level of sophistication and a willingness to get involved. Contractor and suppliers were appointed from the beginning. The architect issued drawings in a collaborative relationship with the owner, contractor and suppliers. Decisions are made when they need to be made to eliminate redundant work. Contractor and suppliers are able to share their knowledge and expertise when it is most valuable in the design process.

stair at 1st Floor

Rotunda House, Millbrae, California

This project is located within the 65 CNEL Aircraft Noise Footprints based upon the Federal Aviation Administration (“FAA”) 1983 CNEL Noise Exposure Map.  If the properties within this map is constructed after Jan. 1st 1983, or is renovated at a cost equal to 25% or more of the current market value of the home, it must be insulated against aircraft noise to meet FAA noise insulation program standards.  This means that the windows must have a Sound Transmission Class (or STC) rating of 35.  A typical interior wall with one layer of 1/2″ gypsum board on each side of wood stud at 16” on center has an STC of approximately 33.

The window manufacturer we selected cannot provide STC 35 certification as a whole window assembly but the glass itself will perform the STC rating of 30 – 35.  We explained the situation with the building official and were able to obtain approval with the glass specification.

Click here for list of homes in the noise exposure area.

Click here for project images