Net-Zero Energy in Single Family
Residential Projects: Leveraging
Sefaira Concept™ to Design High
Efficiency Affordable Housing
Sefaira Concept™ helped The Miller Hull Partnership perform energy
simulation modeling on a pro-bono project for Habitat for Humanity
Seattle-King County
C A S E S T U DY: M I L L E R H U L L
The Customer
The Miller Hull Partnership, established in 1977 by David Miller and
Robert Hull, is an architecture firm based in Seattle and San Diego. The
firm is recognized as a national leader in sustainable architecture and was
awarded the American Institute of Architects Firm Award in 2003.
In 35 years and with hundreds of millions worth of completed projects,
Miller Hull’s work base is composed of a diverse assortment of project
types — from neighborhood park structures to a $577 million border
crossing. Miller Hull specializes in projects such as schools, higher
education facilities, nature centers, community centers, mixed-use
buildings, laboratories, and corporate offices. In addition, the firm is noted
for the design of innovative and affordable residences.
The Project:
House of the Immediate Future
The Miller Hull Partnership, Habitat for Humanity Seattle-King County,
and the Seattle Center Foundation Next 50 partnered to design and
build the 2012 House of the Immediate Future. The house was meant to
be a counterpart to the House of the Immediate Future Exhibit held at
the 1962 World’s Fair in Seattle. Construction of the house at its initial
display location in the shadow of the Space Needle began last April.
Upon the close of the Next 50 celebration, the house was disassembled
and is now being reconstructed at its permanent home in New Rainier
Vista, a transit-oriented neighborhood in Rainier Valley. Both phases of
construction utilized Habitat’s methodology of community engagement
and volunteer labor.
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C A S E S T U DY: M I L L E R H U L L
The Challenges
The House of the Immediate Future’s program required long-term
operational affordability, which could be achieved by designing for netzero annual energy consumption. Due to the non-profit nature of the
undertaking, all project participants worked on a pro-bono basis. As such,
the design directives were determined via fast-paced, collaborative “Think
Tank” workshops, where over 60 local experts could have maximum
input in a short amount of time.
The team generated strategies that could
be universally applied to other nearterm Habitat projects by focusing on the
“immediate” component of the design
challenge, and seeking the right blend of
established but forward-looking building
systems and construction techniques.
The result of this collaborative process
produced a number of potential strategies
that then had to be analyzed, validated,
and prioritized – at a negligible cost –
before they could be worked into the
design drawings.
The Project In Situ
C A S E S T U DY: M I L L E R H U L L
The Solution – Sefaira Concept™ for
Real-Time Sustainability Analysis
Miller Hull used Sefaira Concept™ to rapidly model heating and cooling
loads for four distinct design cases:
1.
2.
3.
4.
Compliance with the local residential building code
Improved envelope performance above and beyond code compliance
High-efficiency HVAC added to an improved envelope
Rooftop photovoltaic panels added to high efficiency HVAC and an
improved envelope
To execute the four models, Miller Hull was required to enter into Sefaira
Concept™ only three global inputs: the project’s location, the house’s
usage profile, and a simple SketchUp® model of the building itself. Next,
the architects created individual concepts for the design cases, each one
a slight derivation from its predecessor.
As displayed in Sefaira Concept’s comparison report on page 5, Miller
Hull modeled Design Case #2 (named HP Envelope Load Calc) by adding
the following to the Design Case #1 (Code Baseline); improved glazing via
reduced thermal transmittance (U-factor), a tighter building envelope
via lower structural leakage, and improved thermal resistance (R-value)
in the walls, roof, and ground floor. The Design Case #3 (Design Case)
enhanced sustainability even further by improving the HVAC system from
electric resistance space heating with a coefficient of performance (COP)
of 1, to an air to water heat pump with a COP of 4.6.
The addition of photovoltaic panels to 86% of the roof is projected to
contribute 3,678 kBTUs to the house’s primary electricity needs. Add the
28,445 kBTU that could be exported back to the grid, and the design for the
house can be confidently considered net-zero.
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C A S E S T U DY: M I L L E R H U L L
Sefaira Concept’s Comparison Report
Code Baseline
HP Envelope Loads Calc
Design Case
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C A S E S T U DY: M I L L E R H U L L
The Result
By limiting the heating load through tightening of the envelope, and then
satisfying that load with high efficiency HVAC equipment, Miller Hull was
able to reduce the House of the Immediate Future’s energy use intensity by
(EUI) 38%, from the base concept to the final design.
With the most efficient design identified and verified in Sefaira Concept™,
the continued design process produced a buildable result that was first
constructed for display by both professionals and volunteers in the shadow
of Seattle’s Space Needle. The house’s reconstruction in a transit-oriented
development in South Seattle is currently under way, under the auspices of
Habitat for Humanity Seattle-King County. With photovoltaic panels added
to the roof, the project has the potential to become a net energy generator
for the new owners.
“
- Jim Hanford
AIA, LEED AP | Energy Specialist at
The Miller Hull Partnership
KEY BENEFITS
• Sefaira Concept’s detailed building physics data validated the
project design
• Sefaira Concept’s robust analysis engine enabled the calculation
of multiple strategy combinations
• Sefaira Concept’s cloud-based technology facilitated a quick cycle
per iteration, limiting Miller Hull’s energy modeling expense on
the project
C A S E S T U DY: M I L L E R H U L L
About Sefaira
Sefaira was founded in 2009 with a mission to promote more sustainable
buildings by helping the building industry design, build, operate, maintain
and transform all facets of the built environment.
Sefaira’s proprietary cloud-based technology, built upon deep building
physics expertise, offers an integrated approach to sustainable design
analysis, knowledge management, and decision support. Sefaira helps
designers analyze and compare sustainable building strategies for new
build or retrofit projects in a fraction of the time and cost previously
required. By providing sophisticated analysis via an intuitive web
interface, Sefaira helps users define, quantify and optimize the energy,
water, carbon and financial benefits of relevant design strategies.
Sefaira’s offices in London and New York have supported projects across
the US, Europe, the Middle East and Asia.
CONTACT SEFAIRA
+1 855 SEFAIRA (US)
+44 (0)203 427 6565 (UK)
[email protected]
www.sefaira.com
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Copyright © 2013 Sefaira Ltd.
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