This document summarizes a presentation about passive design strategies for homes in hot humid climates like Texas. It provides examples of over a dozen case studies of homes designed by the presenter to utilize passive strategies like shading, ventilation, thermal mass, and daylighting to reduce energy usage and increase comfort. Owners of these passive homes reported rarely needing to use mechanical cooling or heating except when entertaining guests. The presentation aimed to teach architects the importance of passive design and demonstrate that approaches beyond conventional wood frame construction can create sustainable, resilient homes.

1. Residential Case Studies of
Passive Strategies
for Texas Gulf Coast and nearby areas
by
LaVerne Williams, AIA, LEED AP
Houston American Institute of
Architects
GULF COAST GREEN 2013

2. ENVIRONMENT ASSOCIATES
Architects & Consultants
is a Registered Provider with The American Institute of Architects
Continuing Education Systems (AIA/CES). Credit(s) earned on
completion of this program will be reported to AIA/CES for AIA
members. Certificates of Completion for both AIA members and non-
AIA members are available upon request.
This program is registered with AIA/CES for continuing professional
education. As such, it does not include content that may be deemed
or construed to be an approval or endorsement by the AIA of any
material of construction or any method or manner of handling, using,
distributing, or dealing in any material or product.
Questions related to specific materials, methods, and services will be
addressed at the conclusion of this presentation.

3. Course Description
• Since the mid 1970’s, hundreds of Texas homes designed by the presenter
have incorporated cost efficient passive design and construction strategies
to lower their owners’ overall living cost of while increasing occupant
comfort and health and improving overall building performance and
durability. Unlike active mechanical systems, for example “active” solar
systems that mainly perform only one function – to generate electricity or
to heat water or air, passive strategies are building integrated to provide
multiple benefits. These building and site integrated passive strategies
developed or improved by the presenter combine to enhance overall
project performance. Some add very little cost, if any, to construction. Even
in the Houston’s Hot Humid climate and in less humid inland Texas regions,
numerous owners of passive homes designed by Environment Associates
proclaim: “We rarely have to use our home’s mechanical cooling or heating
system unless we have guests.”

4. Learning Objectives
At the end of this program, participants will be able to:
1. Learn about the importance of using various passive strategies for improving the
performance of homes located in hot humid climates and the importance of these
systems for improving quality of life.
2. Learn how passive strategies provide natural cooling and heating, enhance and
extend comfort, reduce exterior maintenance, create highly day lighted interiors,
encourage porch and outdoor space use, moderate interior temperature
fluctuations, provide thermal cooling and heating storage, etc.
3. Demonstrate the importance of using passive building construction technologies
besides insulated wood frame as we strive for building resilience and sustainable
lifestyles.
4. Understand the hierarchy of passive design strategies such as shading, ventilation,
building orientation, interior mass, and air-tight envelopes.

5. • Cupola Stack &
Venturi
Ventilation
• AAC Exterior &
Interior Mass
• Healthy Bldg
Materials
• Daylighting
Healthy AGBP 5 Star Shapatyavedic,
2000 Austin

6. We don’t usually don’t use our
Mechanical Cooling or
Heating systems unless we have
visitors
Healthy AGBP 5 Star Shapatyavedic,
2000 Austin

7. Sleeping Porch Home,
2000 Wallis
Humidity,
more than
heat ,drives
Mechanical
Cooling use
• Library Cupola Room stack & Venturi
ventilation
• Deep overhangs for shading open
windows
• Main living area above ground humidity
plus up in breezes
• Screened sleeping porch

8. West Facing Water Front Home,
1982 Kemah
• Dog Run and breeze capture
• Interior mass
• Daylighting
• Shaded windows and outdoor
living spaces
• View without sun load
• Low cooling load for running a/c
• 1/3 Neighbors bills
• Private balconies
• Vent Skinned exterior walls

9. West Facing Water Front Home,
1982 Kemah
Humidity, more than heat,
drives Mechanical Cooling
use

10. • 100% Passive Solar heated & cooled
integrated greenhouse
• ICF Thermal mass
• Separate Natural Ventilation for
Greenhouse and for House
• 2000 sf/ton a/c when originally built
• HARC Research Project
• Passive design year-round porch
The Orchid House,
2004 Magnolia

11. The Orchid House,
2004 Magnolia
Humidity, more than heat,
drives Mechanical Cooling use

12. Green House on the Prairie,
2004 Navasota
Humidity, more than heat, drives
Mechanical Cooling use
• Clerestory ventilation/daylighting
• Deep Shading Eaves & Porches
• Passive solar heat

13. The Farm House,
1994 Dobbin• Screened Porch for shading
• Clerestory Ventilation & Daylighting
• Cross ventilation
• Roof Monitor

14. The Farm House,
1994 Dobbin
We never turn on the Cool/Heat
system unless we have visitors

15. Cypress Platinum,
2011 CypressHumidity, more than
heat, drives Mechanical
Cooling use

16. Cypress Platinum,
2011 Cypress
• ICF Thermal Mass with Concrete
roofing tile
• Integrated Aviary is 100% passive
solar heated & cooled
• Tower Ventilative Cooling
• Rainwater Harvesting
• PV Solar System
• Mini-split A/C

17. The Green Blue Hue Home,
2009 Houston• Insulated closed conditioned A/C'd
crawl space (flood plain)
• Clerestory vent & daylighting
• PV solar system located atop 2 story roof for
security and tree shading avoidance
• Urban location
Humidity, more than
heat, drives Mechanical
Cooling use

18. The Green Blue Hue Home,
2009 Houston

19. Texas Country Greenhouse Home,
1982 Chappel Hill• 1200 sf 100% Passive solar cooled &
heated integrated greenhouse,
3500 sf house
• Internal thermal mass walls
• Shading roofs and porches
• Daylighting

20. Tonalacalli Platinum, House of Sun &
Water, 2007 Austin

21. Tonalacalli Platinum, House of Sun &
Water, 2007 Austin• Shading eves and porches
• 100% Passive cooled and heated Greenhouse
• 100% Rainwater. No well or municipal
connection
• Clerestory daylighting and ventilation
• PV and Solar water heating systems
• Non-vented attics
• Stack ventilation
• AAC walls, 1st floor

22. SSEC Houston Passive Solar
Demonstration Home,
1979-80 Houston

23. SSEC Houston Passive Solar
Demonstration Home,
1979-80 Houston• This home launched the green
building movement in Texas in 1979-80
with 30,000+ visitors
• Built-in Passive solar water heating system
• Interior mass walls
• Adjustable shading & fixed shading
• Clerestory daylighting/Venturi ventilation
• Vent-skinned west wall

24. The Wareloft,
2008 Houston
We never turn on the Cool/Heat
systems unless we have visitors

25. The Wareloft,
2008 Houston• Has interior volume equivalent to 5800 sf
home with 9 ft ceilings
• Fiber Cement clad insul. 2x6 wood frame
• All roofs slope optimally South
• Metal roofs

26. • Added Family Room & Sleeping Loft
with vent skin roof & walls
• Attic ventilation & radiant barrier
• Passive batch type solar water heater
• Added attic insulation
• Replaced windows
What wasn't done
probably more
important than
what was done
Passive Design Solar Addition,
1982 Bellaire

27. We doubled the interior
volume and use half the
energy than before the
addition
Passive Design Addition,
1982 Bellaire

28. Earth Embraced Home,
1980 Manvel

29. This concludes The American Institute of Architects
Continuing Education Systems Course
QUESTIONS ????
EcoArchitect LaVerne A. Williams, AIA, LEED AP
architect & bioneer, building ecologist, ceo & founder
ENVIRONMENT ASSOCIATES
Architects & Consultants Houston Texas
LaVerne@EnvironmentAssoc.com
713.528.0000
Established 1975