Building sustainable communities the habitat for humanity of greater memphis story

High Performance Homes

Jack Cowan

cowanhouse

www.cowanhouse.com

June 27, 2013

What is a High Performance

Home?

• A home that has significantly improved

features to provide reductions in heating,

cooling and operational costs when

compared to existing housing, while

maintaining indoor comfort and health.

(cowanhouse)

Why should we build performance

homes?

• Environmental impact and ownership costs

• Our housing model is not sustainable! – Designed around the false premise that fossil fuel

would always be cheap and available in unlimited quantities

• Little or no consideration has been given to environmental impact, with NO VISION of the resulting consequences – We don’t see or feel the immediate pain of fossil

fuel energy use…only enjoy the derived benefit (see video Kilowatt Ours by Jeff Barrie)

New homes use more energy, cost

more and pollute more

• Early houses – Small size

– Small energy loads

• Newer houses – Larger size

– More of them (world population at 7.15B vs 2.56B in 1950)

– Huge energy loads • Many more appliances (phantom loads)

• Central heating and air conditioning

• Clothes dryers, dish washers, exhaust

Houses are getting bigger and

space per occupant has tripled! Source: Your Green Home, Wilson, 2007

1950 vs 2004 U.S. Housing

1000

294

2340

900

0

500

1000

1500

2000

2500

House size in ft. Feet per occupant

Sq

ua

re f

ee

t

1950

2004

Looking forward:

• Energy from burning fossil fuel will

continue to be expensive and will continue

to pollute. Therefore:

• We need a housing paradigm change that

moves us toward energy independence by

transitioning to high performance houses

So, what does a high

performance home look like?

How do we determine a home’s

performance? HERS Index

• Home Energy Rating System (HERS)

Index offers a quantified method of

determining relative performance, much

like EPA gas mileage ratings. Houses are

computer modeled, tested for

performance, and assigned a numerical

value.

What is a Net Zero Energy

Home (ZEH)?

From Wikipedia

A zero-energy building, also

known as a zero net energy

(ZNE) building, net-zero energy

building (NZEB), or net zero

building, is a building with zero

net energy consumption and zero

carbon emissions annually

http://en.wikipedia.org/wiki/Building

Net Zero Energy Home

vs Zero Energy Home

So, how do performance

houses impact?

• Environment • Total Cost of

Ownership (TCO)

Habitat Home on Pershing vs

existing home and new standard home

0

2

4

6

8

10

12

Existing New Std Habitat

Tons/Yr CO2

CO2



0

10

20

30

40

50

60

70


Sulfur Dioxide

Nitrogen Oxides

Lbs/yr



$0

$500

$1,000

$1,500

$2,000

$2,500


utitility cost

utitility cost

Increased Market Value

• EPA funded study by ICF Inc. suggested

that with every $1 reduction in annual fuel

bills, home value should increase from $10

to $25

Source: Evidence of Rational Market Valuations for Home Energy Efficiency, Nevin

and Watson, The Appraisal Journal, Oct 1998

Cowanhouse Hi-Performance Requirements

for new homes

– Informed Occupants – Imperative! Includes knowledge of sustainability and healthy indoor environments, as well as knowledge of the financial, environmental and operational impacts of high performance buildings. The ultimate QA.


for new homes

– Site Optimization – Solar & shading orientation (can save as much as 10% on htg/clg), water management, and minimal environmental impact. Identify and avoid potential pollution sources.

SunTempering

• No or Low cost

• Elongated structure with maximized southern exposure

• Minimized east/west glazing

• Dominate southern window exposure with appropriate controls for winter/summer solstice

• Designed passive gains and mass consideration

Look at sun strike on windows

Aug 8th

Think

about

March 20,

Sept, 22,

and Dec

21 Sun

strike


for new homes

– Building shell – Size to minimum needed, with design to meet functional needs. Must provide moisture protection, enhanced thermal resistance and total air sealing. Plan for change!

Houses are getting bigger and

space per occupant has tripled

1950 vs 2004 U.S. Housing

1000

294

2340

900

0

500

1000

1500

2000

2500

House size in ft. Feet per occupant

Sq

ua

re f

ee

t

1950

2004


for new homes

– Heating, Ventilation and Air Conditioning (HVAC) – Passive gains, conditioned envelope located air distribution systems, highest performing equipment that budget will support. Controlled and scrubbed fresh air intake.

Reduction in total heating and cooling load

achieved by moving ducts inside the building’s

conditioned space. 36.4%


for new homes

– Other – Daylighting, performance lighting, high performance water heating and appliances, and optimally, solar PV and solar water heating.

Do these performance features

really work? Case study: FRZEH

• Case study: FRZEH (Fats’ and Reeda’s Zero Energy Home), located in Atwood, TN, completed in January 2009

• Now (April 25, 2013) 62,397 pounds of CO2

emissions have been offset by photovoltaic (PV) energy production on this zero energy home.

Feb March

Does it work?

Thanks!

• Discussion?

Building sustainable communities the habitat for humanity of greater memphis story

Technology

Transcript of Building sustainable communities the habitat for humanity of greater memphis story