Green Roofs - Living Architecture Monitor - Winter 2017 - 25

POLICY NAME
San Francisco Better Roofs Ordinance

"SHOULD THE CURRENT
RATE OF DEVELOPMENT
CONTINUE, IT'S
ESTIMATED THAT SAN
FRANCISCO COULD SEE
AS MUCH AS 1.5 MILLION
SQUARE FEET OF NEW
LIVING ROOFS BEING
NEWLY ESTABLISHED
EACH YEAR."
- JEFF JOSLIN

Francisco Department of the Environment to
advance a holistic Better Roof Ordinance.
A detailed cost-benefit study was also conducted that tested various likely building uses and
scales, and demonstrated the cost efficacy at both
the project and the city scale. City scale benefits
were determined to include:
* $15 - 100 million of tax revenues in the first
five years from improved property and
biophilic value;
* 60,000 - 385,000 tonnes of carbon emissions
avoided or sequestered over 15 years, a critical
period for reducing the anticipated impacts of
climate change, equaling:
* the sequestration of 3,600-24,000 acres of forest
* the energy used by 400-2700 homes
* 800-5400 cars off the road
Should the current rate of development continue,
it's estimated that San Francisco could see as
much as 1.5 million square feet of living roofs
being newly established each year.

LIVINGARCHITECTUREMONITOR.COM

POLICY DESCRIPTION
The Better Roofs Ordinance requires
between 15 and 30 per cent of roof space
on most new construction to incorporate
solar, living roofs, or a combination of both.
The living roof option allows developers to
replace required solar (15 per cent) with
living roof at a rate of 2 sq.ft of living roof for
every 1 sq.ft of solar.
DATE PROPOSED, APPROVED & IMPLEMENTED
Proposed Summer/Fall 2016
Approved Planning Commission: September 15th, 2016
Approved at Board of Supervisors: October 17th, 2016
Effective January 1, 2017
CITY DETAILS
Population: 864,816 (2015)
Plant Hardiness Zone: 10B
Climate: Mediterranean climate, mild temperatures, little rainfall
Average rainfall: 23.64 inches/year
Average temperature: 57 degrees F
POLICY DRIVERS
* Efficient and best use of space in an dense urban city
* A more green and sustainable city
* Connecting people to nature & creating habitat
* Improved stormwater management
* Air quality improvements
* Biodiversity/biophilia increases
* Job creation opportunities
ANTICIPATED CHALLENGES
* The policy negatively impacting the cost of affordable housing
* Drought/lack of water creating an issue for planting
* Competing rooftop uses (urban agriculture, open space, etc.)
* Buildings becoming shaded in the future
SOLUTIONS
* Developed a Cost Benefit Analysis to show the affordable options for different green
roofs compared to normal and white roofs
* The Living Roof Manual provides recommendations for plants that are drought tolerant
* Continued coordination with sister agencies
MONITORING IMPACTS
* Track impacts using a permit tracking site
* Update living roof data base as projects are approved
* Track square feet of living roofs and square feet of solar roofs
* Data will be used to calculate stormwater runoff mitigation and air pollutants impacts
* Size and location of living roof are important when determining impacts
o Ex. A large living roof located near a freeway will have substantial
air pollutant benefits
IMPLEMENTATION TOOLS AND RESOURCES
Please visit sf-planning.org/san-francisco-better-roofs for links to the ARUP Cost Benefit
Analysis, Living Roof Manual, and the SPUR Report: Greener & Better Roofs.
LIVING ARCHITECTURE MONITOR / WINTER 2017 / 25
http://www.sf-planning.org/san-francisco-better-roofs http://www.LIVINGARCHITECTUREMONITOR.COM
Table of Contents for the Digital Edition of Green Roofs - Living Architecture Monitor - Winter 2017
