resilient design - cdn.ymaws.com · principal / multifamily housing team leader resilient design....
TRANSCRIPT
Rachelle MacurSenior Sustainability Advisor
Michael LevinsonPrincipal / Multifamily Housing Team Leader
RESILIENT DESIGN
Building and Operating for the next 50 years
Impacts of Climate Change
Drought25-50% increase in water withdrawal over next 50 years
Flooding Flash flooding expected to triple over the next 100 years in Rocky Mountain range
Severe Winter StormsSevere storms can cause power outages and closures of streets, schools, and businesses
Hail StormsMore than $5 billion in damage in CO in past decade
Extreme HeatAve temperature expected to rise 2-5 degrees F in next 50 years
WildfireFire frequency and intensity increases with rising greenhouse gas emissions
Average temperature is likely to increase by 2-5 °F by 2050
Vulnerable PopulationsExtreme heat episodes in much of the region disproportionately threaten the health and well-being of individuals and populationswho are especially vulnerable… Communicable diseases, ground-level ozone air pollution, dust storms, and allergens can combine with temperature and precipitation extremes to generate multiple disease burdens. US Fourth National Climate Assessment – 2018
Mortality rates expected to increase to annual average of 13,000 by 2050. – Natural Resources Defense Council
DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
Heat is one of the biggest climate-related public health threats, according to the CDC
Contributors to Heat Vulnerability
• “Heat Island” effect• Shading vegetation• Neighborhood
demography• Vehicle ownership• Income levels
DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
US Water Demand in 2050DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
Effects of Drought on the Built Environment
- Water scarcity- Sinking and shifting of land- Expanding and shrinking soil- Flash floods
CO River Compact allocated water rights based on river flow from 1897 -1922
Recent river flow has been 1/3 of the 17 million acre feet allocated
Likelihood of a “megadrought” happening before 2100 at 70% (35 yrs)
DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEAT DROUGHT
Wildfire and Air Quality
“In the last few years, we’ve seen enormous spikes in episodes where wildfires contribute to pollution,” said Janice Nolen [American Lung Association]. “It doesn’t have to be a continuous problem every day to be unhealthy. It can be that a spike happens for a few days of difficult breathing that shorten lives.”
DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEAT WILDFIRES
FLOODDROUGHT WILDFIRES SEVERE STORMSEXTREME HEAT
DENVER
FLOODDROUGHT WILDFIRES SEVERE STORMSEXTREME HEAT
DENVER17%of homes hit by the 2013
floods were outside of the mapped floodplain
• FEMA flood maps based on historical data only
• Takes 2-3 years to update a region
• Study shows actual risk is 3x higher than what is shown in FEMA flood maps
DROUGHT WILDFIRESEXTREME HEAT
70% of Major Power Outages Caused by Severe StormsFLOOD SEVERE STORMS
Fresh air that doesn’t impede lung function
Space temperatures within safe parameters
Access to potable water
Ability to evacuate to safety
Critical Mission Risks
Real Estate Risk Factors• Catastrophes
• Increased Insurance Premiums• Capital Expenditures• Higher Operating Costs• Decrease in liquidity and value of
buildings
• Transitional Risks• Locational decrease in value• Obsolescence of assets
“Investors acknowledge that using insurance as the main protection for asset value is not an effective solution to mitigate the risk of devaluation, particularly because premiums currently are largely based on historical analysis and are not likely to consider future climate risk.”
“A plus-4-degree C world is not insurable”
– ULI, Climate Risk and Real Estate Investment Decision-Making
Redundancy and diversity Simple, passive, flexible Durability Locally available, renewable,
and reclaimed Social equity and community
Resiliency Principles
DESIGN STRATEGIES
Heat IntensityHeat Waves, Heat Intensity, Extreme Temperatures
Insulation• Continuous insulation around building’s envelope.• Air handler and ductwork also be within the thermal
envelope.
Windows • Small windows that minimize the heat gain, particularly on
the west side of a building. • The main windows of a building, for both light and
ventilation, should face north and south. • Double pane argon filled in non-metal framing.
Shading• Shading over windows subject to heat gain. Awning works
well on east and west-facing windows where the sun strikes lower. Overhangs are effective on the southern face with the sun is at its highest.
• Install exterior shades, interior blinds and curtains, and provide shade near windows with vegetation.
EnvelopeDROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
• Consider sizing cooling systems with higher design temperatures in mind• Portable evaporative cooling systems may be a good back-up solution,
especially for vulnerable populations
Cooling SystemsDROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
Providing control for residents of their home so that they can be comfortable even during power outage, extreme heat, and peak energy use times. Strategies include:• Ceiling fans: Moving air evaporates
moisture from our skin, cooling the skin surface
• Interior shading and drapes – black out shades
• Operable windows to provide for natural ventilation – consider cross ventilation through unit layout and building shape.
In-Unit ControlDROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
• Spaces in building for heatwave respite and survival. Highly insulated, well-shaded cool rooms with little window areas and effective cooling system –preferably with backup electricity supply.
Spaces of RespiteDROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEATEXTREME HEAT
DROUGHT
Drought Mitigation: Water Efficiency
Reduce indoor water consumption
Greywater reuse
Rainwater harvesting & on-site water storage Install low-flow equipment
Low flow faucets & showers Low flow or composting toilets Waterless urinals Water efficient appliances
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DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEAT DROUGHT
WILDFIRES SEVERE STORMSEXTREME HEAT
Site Water ManagementFLOOD
Green infrastructure to allow stormwater to replenish ground water
Xeriscape to reduce need for watering landscape
Plant drought-tolerant native plants and trees to provide shade
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Permeable paving allows
precipitation to replenish ground
water supply instead of being
funneled into storm sewer.
Providing shade, especially for
riparian areas, helps reduce the
rate of evapo-transpiration.
Use water-efficient, native species of trees.
Install bioswalesto collect and
filter stormwaterfrom impervious
areas and gutters, allowing
stormwater to recharge the groundwater
supply.
DROUGHT
When soil undergoes dramatic changes in moisture, such as extended periods of dryness followed by a period of moisture, the shrinking and expanding of the soil can cause foundations to shift, crack, and sink.
Some smart decisions can help minimize the effects:1. Plant trees a safe distance away from foundation, to
reduce unevenness of the ground due to future tree root systems.
2. Plant smaller plants, such as flowers and shrubs, around the base of the foundation to help retain moisture and keep the area shaded.
3. Avoid building on areas with a high slope or known to have shifting land. High clay content soils are also more susceptible to shifting due to moisture loss.
4. Inspect the foundation regularly for damage.5. Investigate non-traditional foundation options that are
more resilient to shifting soil.
DROUGHT WILDFIRES SEVERE STORMSFLOODEXTREME HEAT DROUGHT
Foundation Considerations
WILDFIRE & AIR QUALITY
DROUGHT SEVERE STORMSEXTREME HEAT
Wildfire MitigationFLOODWILDFIRES
MITIGATION EFFORTS
Primary determinants of a home’s ability to survive a fire are roofing material and surrounding defensible space.
- Break up continuity of horizontal and vertical fuel sources
- Replace wood shingled roofs with non-combustible material
- Prescribed fire control (burns)
Homes with 30’ defensible space and non-combustible roofs have a 85% survival rate in the event of a wildfire.
DROUGHT SEVERE STORMSEXTREME HEAT
Indoor Air QualityFLOODWILDFIRES
• Check filters for dust and debris buildup at least every month during heavy smoke seasons, consider pre-filter.
• Mechanical Supply or Balanced Ventilation with minimum MERV 8 filters
• Educate occupants about when to use natural ventilation in emergency situations –run AC with fresh air intake closed off, keep windows and doors closed, close fireplace dampers
DROUGHT SEVERE STORMSEXTREME HEAT
Indoor Air QualityFLOODWILDFIRES
DROUGHT SEVERE STORMSEXTREME HEAT
CommissioningFLOODWILDFIRES
Floods
FLOODDROUGHT WILDFIRES SEVERE STORMSEXTREME HEAT
Flood Mitigation
Dry floodproofing: Seals buildings to keep water out
Wet floodproofing: Allows unoccupied portions of building to be flooded
FLOODDROUGHT WILDFIRES SEVERE STORMSEXTREME HEAT
Elevate mechanical equipmentBoilers, furnaces, water heaters, fuel storage tanks, elevator machine rooms, ductwork, electrical systems.
If not on roof, on raised platform.
Elevate living spacesReserve sub-DFE for parking, storage, entryways
Stormwater managementPermeable paving, green roofs and bioswales infiltrate excess stormwater
Floodwater ventsAllow water to flood lower levels
Wet Floodproofing for New Construction
FLOODDROUGHT WILDFIRES SEVERE STORMSEXTREME HEAT
Backwater valvesPrevent sewage backflow
Sump pumpsRemove water that accumulates at lowest point in building
Low-cost Retrofit Floodproofing Measures
Protect mechanical equipmentBuild barrier around critical systems if it can’t be elevated
FLOODDROUGHT WILDFIRES SEVERE STORMSEXTREME HEAT
Flood risk measures = lower insurance premiums
25% DISCOUNT
15% DISCOUNT
Winter Storms
DROUGHT WILDFIRESEXTREME HEAT
Passive Survivability FLOOD SEVERE STORMS
Backup power + disaster preparedness planFuel-fired backup generators, solar with battery storage, micro-gridSnow removal plan for building ingress/egress
High performance building enclosure in case of power outagePassive solar strategies (orientation, thermal mass, high SHGC windows)Tighter, higher performance envelopes (durability for hailstorms)
Provide access to potable waterRooftop storage, gravity-fed
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3 Strategies to address winter storm occurrences:
EMERGENCY MANAGEMENT MANUAL
• Site details• Vulnerabilities assessment• Contacts and Communication plan• Emergency procedures• Roles & Responsibilities
CREATING COMMUNITY RESILIENCEPrepare for anticipated hazards, adapt to changing conditions, and withstand and recover rapidly from disruptions
Resident Education & Engagement
Stakeholder Incentives to Invest in Resilience Measures
Home / Building Owner: Reduced insurance premium, tax reduction, later building owners may pay more for resilient buildings. Reduced repair costs, accelerated recovery, reduced chance of mortgage default
Occupant: Enhanced safetyBuilder: Increased market value of buildingInsurer: Reduced portfolio riskLoan Provider / Financer: Increased loan security, increased financing
opportunities, asset risk reduction
Benefit-Cost Ratio of Mitigation Strategies
Resilient Design in Green Building Certification Standards
• LEED ReLi credits• Passive House Institute• Army Corps of Engineers• Enterprise Green
Communities• International Green
Construction Code (IgCC)
Resilience starts with strong, regularly updated, and properly implemented building codes.- International Code Council (ICC)
Q & A
Michael LevinsonPrincipal
Group14 Engineering, PBC(720) 221-1077
Rachelle MacurSenior Sustainability AdvisorGroup14 Engineering, PBC
(720) [email protected]