Tonalacalli

"House of Sun and Water"
 Austin, Texas

The Official First Certified LEED^® Platinum Project
is also
The Official First Certified LEED^® Home
in the
Birthplace of U.S. Green Building Programs, Austin Texas

Awarded a Platinum level rating (The U. S. Green Building Council's highest possible rating)
and
a Five Star level rating (The Austin Green Building Program's highest possible rating)

Description

Being a one & one-half story house designed on an elongated East-West axis only begins to describe the sustainability of this high performance home. Extensive porches along both the South and West sides serve to shade the structure from summers' heat gain, while allowing winters' warmth through the numerous windows. Designed with many flex-space areas, two of the four-bedrooms will be used by current owners as Office and Studio space, yet the two and a half baths are more than enough to accommodate a larger family. The home is specifically designed for the terrain and microclimate of the site and constructed to provide low energy consumption and healthy living conditions with low-maintenance while using as many durable natural materials as possible within the original owner's budget.

The concrete slab-on-grade house uses highly insulative Aerated Autoclave Concrete block for the ground floor walls which also offer excellent defense against termite damage. Walls are mud plastered on the interior with a stucco exterior. The partial second floor and two story vaulted spaces are constructed using 2x6 foam filled walls having textured and painted sheetrock interior walls and stained fiber cement exterior wall finish. All roofing is standing seam metal on foam insulated wood framing. House finishes include wood flooring milled from reclaimed long leaf pine along with stained concrete, clay tile, and linoleum flooring. Extensive stone walkways and garden walls were partially constructed using the stone from foundation and other construction excavations on site, with the balance trucked from a nearby quarry. Most of the interior wood trim, columns and exposed beams are made from Central Texas woods and Master Bath cabinets are Texas mesquite, all having a no VOC finish.

A separate Carport/Greenhouse/Workshop structure (connected to the house by covered stone walkway) consists of an oversized two vehicle Carport, a 200 sf passive designed Greenhouse with a 400 sf Workshop (both passive designed to be have wind assisted thermal chimney natural ventilative cooling, passive solar wintertime heating and exceptional year round natural daylighting). This structure has standing seam metal roofing to match house with stained fiber cement clad wood framed walls on a concrete slab foundation with painted sheetrock interior. Minimal disturbance of the site was amended by a native landscape incorporated into the native stone-walled front courtyard.

Passive Sustainability (sometimes referred to as passive survivability)

This home is intentionally designed for Passive Sustainability... i.e., to have the ability to naturally maintain relatively comfortable livable conditions for the occupants during times when there may not be power or water or food available from off-site sources.

Along with direct gain passive solar heating for wintertime heating, one of the principle features is the Venturi effect-assisted passive thermal stack ventilative cooling systems designed into both the house and the greenhouse/workshop building for the overheated months.

For this house, the house design itself is the primary cooling/heating system which also incorporates thermal capacity, i.e., the ability to store heating and cooling, in the exterior walls and foundation. The electric powered cooling and heating system is the back-up cooling and heating system, not the primary cooling and heating system.

Other Passive Sustainability design features that assist the performance of the house and greenhouse/workshop are: the calculated roof overhangs and strategically placed shading porches; the window locations (along with their sizes and types) and their placement for cross ventilation and design for natural daylighting; and an air-tight envelope. All of the water supply for the house and the gardens is supplied by the rain water harvesting systems. The owners' intent is to grow all their vegetables and fruits from a kitchen garden (between kitchen and greenhouse) and from fruit trees scattered around the property The gardens along with fruit trees will be able to supply most, if not all, of the owners fruit and vegetables, should this become necessary. Easy accessibility to the gardens from the house is another Passive Sustainability and Permaculture design feature. And the solar water heating system can supply their hot water needs. (Note: A home must be intentionally designed, or redesigned, for Passive Sustainability. It doesn't happen by chance or by addition. And it is not something that can be bought and added on, like an appliance.)

Green Building Features

Water Supply

• Rainwater harvesting: 100% rainwater for both indoor and outdoor water consumption; no well or municipal water connection

Water Heating
Solar water heating system with 80 gallon storage
Efficient Energy Performance achieved by

• Passive Survivability & Passive Solar architectural design features (Awarded Innovative/Regional Design Credit): orientation, overhangs/porches, window locations, thermal chimney (effective cross and stack ventilation)
• High efficiency building system (AAC block walls and spray foam at roof rafters)
• Very high efficiency HVAC system with variable speed air handler (non-HCFC refrigerant) and ductwork within thermal envelope
• Energy Star labeled appliances and use of CFL bulbs for lighting
• Porches designed and positioned for summertime breezes for extended usability & provide building and occupant shading
• Operable Windows positioned and sized to augment natural ventilation during overheated season and to provide views, natural daylighting, passive solar heating (in winter only)
• Mass effect of mud plastered AAC walls, stained concrete and tiled floors, and adobe hearth provide additional thermal capacity storage for reducing cooling and heating loads

Site Plan (click to enlarge)

Location/Sustainable Sites

• Site Selection met all requirements for sustainable site designation (NOT within a flood plane, wetlands, prime farmland, public parkland, or habitat for endangered species)
• Development included limited turf, native (drought tolerant) plants, permeable sites with permanent erosion controls (retaining walls and storm water management)

Building Durability

Durability does not mean just the use of durable materials like stone. Durability must be designed and built into the home so that design features and their correct execution during construction don't contribute to premature aging and failure.

• Installed stainless steel mesh to address termite risk in lieu of soil poisoning
• All exterior envelope penetrations thoroughly sealed to prevent critter entry
• Extended roof eves to reduce wall, window & door exposure to wear by the sun and rain
• Roof design kept simple to prevent leaks due to water and debris accumulation

Environmentally Preferred Product Use
(Awarded 3 additional Innovation Design credits beyond the maximum of 8 credits available in the program)

• Used many local materials: eastern aromatic cedar used for 100% of interior trim; Central Texas mesquite stair treads; Eastern Cedar Logs from Central Texas for exposed columns
• On-site mountain juniper used for stair railing, fencing and exterior deck
• Local clay plaster interior walls for all first floor walls
• Exterior stone is quarried locally (30% quarried onsite)
• AAC block manufactured within 500 miles of jobsite
• Foundation aggregates quarried locally
• 200 year old long-leaf pine flooring from reclaimed timber from projects within 500 miles of jobsite
• Metal roof is manufactured locally
• Adobe hearth made from local sourced materials

Recycled/Renewable Content

• Fly ash over 30% content in concrete foundation cement
• Over 90% of flooring in made from products having reclaimed content, including linoleum, cork, reclaimed long-leaf pine wood, and sealed concrete

Indoor Air Quality Matters

• Detached carport
• Low-VOC emissions specs:
  • All interior trim has no added urea-formaldehyde resin
  • Roof, floor and wall insulation complies with California testing for VOC's from building materials
  • Adhesives and sealants are all low-VOC or materials were installed without adhesives or sealants
  • Interior wall, ceilings and millwork paint complies with Green Seal Standard GS-11
  • No carpet in home.

Construction Waste Reduction

• Over 38% waste reduction from selection of building systems with minimal waste and recycling efforts made as well as recycling done by the homeowners

Renewable Energy

• Solar Photovoltaic (PV) System:16 panel roof mounted array supplying 3.3 DC KW (being easily expandable to achieve 'net zero' energy use when desired by adding additional PV panels due to ideally designed roofs having more than adequate area to expand system)
• Wood-burning stove meets EPA requirements for combustion safety

Other Features

• Water permeable all-weather gravel driveway
• An outdoor shower
• Lots of natural daylighting
• Site made adobe for wood stove hearth

Gardening/Landscaping

• Minimal turf and extensive use of native plants
• Innovative fencing concept to possibly keep deer out of vegetable garden adjacent to house

Building Stats

House

• 3082 sf total enclosed living area
• 139 sf mech. room
• 902 sf of roofed 1st & 2nd floor porches & walkway

Carport/Greenhouse/Workshop

• 1272 sf roofed floor area

Project Location

SW Austin. Site Visits by appointment only (see "Contact Info" below). Also, please ask to be added to list for notification about possible tours.

The Building Team

Architect:
   Environment Associates, Architects & Consultants
   Houston, Texas
   Fostering Sustainable Living Concepts & Practices since 1975
   www.environmentassoc.com

   Project Architect & Design: LaVerne Williams, AIA, LEED^® AP
   Support Team leader: Shawn McFarland, AIA, LEED^® AP
   For information, or call 713.528.0000.

Building Contractor:
   Custom Building, Inc.
   Austin, Texas
   Owners: Taylor King & Bill Kelley

LEED^® for Homes Provider:
   (providing rating services for independent 3rd party verification of rating requirements)
   Contects, Consultants & Architects
   San Antonio, Texas
   LEED-H Project Manager/Rater: Miki Cook

What else makes this home so special?

Aside from the owners loving to live in it, the green features and the artistic touches, its extraordinary comfort, its design for Passive Sustainability and aesthetic appeal, what makes this house so especially significant are the "firsts" that it has achieved:

• It is the first LEED home to be certified in the U.S. birthplace for green building programs, Austin Texas.
• It has achieved the highest possible green building certification ratings from the top two premier green building programs in the entire U.S.: On the National level, the Platinum certification from the U.S. Green Building Council's (USGBC) LEED^® for Homes program; and on a Local or Municipal level, the Five Star certification from the Austin Green Building Program.
• It is the very First Platinum LEED project of any type completed anywhere on the Planet by a Houston-based entity of any type.
• All of these firsts have been verified.

Contact Info:

Requesting Information and visiting the house

Visiting the house site is by invitation only, except for announced tours.

For information about the project or to receive announcements about possible tours or visits, please call 713.528.0000 or .

To Construction Photos