Adding Value with Green Roofs by Kirstin Weeks
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1 Adding Value with Green Roofs Kirstin Weeks, Arup Green Roof Professional, LEED AP, CEM
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Adding Value with Green Roofs by Kirstin Weeks
Transcript of Adding Value with Green Roofs by Kirstin Weeks
1
Adding Value with Green Roofs
Kirstin Weeks, Arup
Green Roof Professional, LEED AP, CEM
Sir Ove Arup founded his practice in 1946 based on a belief in ‘total architecture’ integration and interdependence, innovation and the social purpose of design.
We shape a better world.
Photo Credit Lisa Lee Benjamin
Image: safeguardchem.co.za
Image Credit: Kay Cheng, SF Planning
Photo Credit Lisa Lee Benjamin
6
7
Photo: Curran House Roof, Credit Brian Rose
Photo Credit Laura Tam, SPUR
Benefits and Uses of Green Roofs
Building Energy Savings,
Improved PV Production Acoustic Insulation
Stormwater Management Habitat and Biodiversity
Aesthetics and Quality of Life Job Generation
Roof Longevity
Urban Agriculture
Urban Heat Island Reduction
Air Quality Improvement
Accessible Open Space Property Value Increase
$
Stormwater Performance
• Retains 30% - 100% over the duration of a storm (up to 3.5”)
• Reduces runoff rate by up to 85% (avg 65%) • Deeper soil, low slope, retention features and
large roofs improve performance.
Heat Island & Energy
• Annual energy savings ~$0.17 per square foot of roof (varies widely by climate and building characteristics)
• Community wide energy and peak load reduction
Biodiversity and Habitat
• Governments developing ways to value natural ecosystems, i.e., Australia’s BushBroker scheme ($0.42 - $1.46/sf)
Photo Credit Laura Tam, SPUR
Quality of Life and Real Estate
• A study showed that access to views of greenery has increased productivity 2.9%
• Potential real estate value of ~$13 per square foot national (rents, expenses, vacancy, discount rates, absorption and lease lengths)
• Green roofs increase premiums of a building (i.e., green buildings) - ~2.5% nationally
age: IRS Kansas City, GSA
Photo: Denver EPA, Credit EPA
Photo: olpos.com
Photo: olpos.com
Green roof costs
• Maintenance costs: $0.04 to $0.30/sf/yr
3” extensive
6” semi-intensive
• Installation costs ($ per square foot): $20
$18 $16 $14 $12 $10
5,000 10,000 50,000
22
($20)
($10)
$0
$10
$20
$30
Installation, Replacement & Maintenance
Stormwater Energy CO2e (Emissions, Sequestration &
Absorption)
Initial Real Estate Effect (Value, Rent
Absorption & Vacancy)
Community Benefits (Biodiv, Air
Quality, Heat Island, etc.)
Net
Pre
sent
Val
ue ($
/ft2 )
GSA Study Results – 30 yr NPV
-$17.5
$14
$7
$3
$13
$30
NPV = $2.70/ft2 IRR = 5.2% Payback = 6.2 years (Simple 15 yrs)
cost of green roof – cost of alternative = true green roof premium
Stormwater Management
Ordinance
83-10 May 2010
stormwaterdesignguidelines SAN FRANCISCO
Image Credit: SFPUC
True green roof cost = max $6/sf, min $0/sf
$3/sf!
min
Looking ahead…
www.spur.org\greenroofs
Roadmap for Green Roof Policy in SF
Image Credit: Kay Cheng, SF Planning
Image: 201 Folsom, Spinnakersf.com Image: Transbay Terminal
Image: Foundry Square IV
Kirstin Weeks, Arup 560 Mission Street, Seventh Floor San Francisco, CA 94105 direct 415 946 0746 mobile 415 730 6444 [email protected] GSA Report Link: http://www.gsa.gov/portal/category/104999
SPUR Roadmap for SF: www.spur.org\greenroofs
Contact Info and Links
