Project Background: Past, Present, Future

The Triehouse is the culmination of almost a decade of research and development in the realm of creative, ultra-affordable ecological housing. In 2004 Adia introduced the “$1,000 Transportable Bedroom” (JKP sleeper), and five years later gained international recognition for its “$12,000 Green Dream Home” (MCDhouse). This was followed in 2010 by a simplified, internationally transportable version of the MCDhouse (adiaHouse, $40,000).

Today we introduce the Triehouse, first in our line of luxury eco-homes—and our attempt to make "exclusive" architecture economical and more widely available. Among other projects and developments, Adia is currently developing a smaller, more affordable, 3 bedroom/2 bathroom version of the Triehouse: “The All American.” Our goal is to show that creativity doesn’t have to cost more, and that elegant, eco-friendly homes should be something every family can afford and enjoy.

Why a Triangle?

Though many contemporary buildings feature unconventional shapes and angles primarily for the sake of aesthetics and “wow factor,” the triangular shape of the Triehouse was derived primarily out of functional necessity. That’s not to say that we didn’t enjoy the challenge of fitting a traditionally rectangular floor plan into a triangular footprint—but that necessity led the way.

There were two primary driving factors in determining the shape of the Triehouse. The first was the location of the trees and the issue of how to fit such a large house footprint in a grove of closely spaced trees. Including the garage/parking, outdoor decks, and infinity pool, the house footprint is almost 7,000 square feet—while the average space between clusters of trees was only 400 square feet. And since the temperature is 20 degrees (F) cooler under the shade of the tree canopy than in direct sunlight—and the trees are critical for protecting the expansive glass walls and windows from direct sunlight—it was important to keep every tree possible. After studying more than 30 creative shapes and layouts, a triangular footprint seemed the most promising.

Of equal importance architecturally was the aspect of framing the best views on the site while hiding several nearby buildings in order to maintain the feeling of being “away from it all.” We did not want a linear building in which each room would have the same view (albeit it the best view) of the site as every other. We wanted a dynamic floor plan allowing each room to enjoy a unique experience of the site and share the best views from alternate angles.

If you were to look at the Triehouse from a satellite photo or site plan, you would notice that the three sides of the triangle correspond to the angles of the three primary views, and that the three points of the triangle are located to create blind spots in order to hide undesirable objects from view [see diagram]. From inside the house, one would never know that there are multi-story suburban homes lining the south edge of the property, an antenna tower to the east, and several neighbors’ homes to the east and west—some within a stone’s throw of the house. A carefully selected footprint was not only important for creating perfect views from the house, but for maintaining privacy—considering that so much of the house (including bathrooms and bedrooms) would be glass.

Try a Triangle | Benefits of a Triangular Footprint

In addition to taking care of the trees and framing the best views, the triangular footprint allowed for several unique benefits:

1) Minimizing Hallways and Circulation Space: A typical rectangular tract home of a comparable size wastes 10 to 12 percent (400+ square feet) of the floor area on hallways and stairwells. Our triangular floor plan required only 2 percent (90 square feet) of the floor area for circulation—meaning less house to build, less space to heat/cool every month, and less time walking from one room to another.

2) Maximizing Views From Each Room Without Compromising Privacy: If you look at the floor plan, you’ll notice that almost every room has views in two or more directions—but that no private room looks into another private room or can be seen from a public part of the house. You’ll also notice that all but one of the six bathrooms has windows, a luxury almost unheard of in a house this size. The triangular shape allowed for rooms with many windows—which was critical not only for creating views but for enabling natural ventilation and natural cooling.

3) Dividing the House into Zones: Every house has four zones: public, semi-public, semi-private, and private. Unfortunately, many tract homes do not account for this, and may place public uses directly adjacent to private ones. But the triangular shape worked perfectly in this regard. The Triehouse is divided into three primary zones: a public area for entertaining guests, a private area for children’s bedrooms, and a private area for the Master Suite. Each of these zones occupies one of the three corners (or “wings”) of the triangle. And in the center of the triangle—connecting and buffering these three zones—are the semi-public and semi-private spaces such as the Kitchen, Family Room, and Media Room. [see diagram]

4) Cost-Efficient Creativity: A triangular house makes quite a visual statement. It’s compelling, creative, and looks exotic and expensive. It’s so much more interesting than a rectangular house. Yet as complex as it may appear, a triangle is just a square (or rectangle) cut in half diagonally. If you could see the structural plan, you would see that all the beams and piers are on a repetitive rectangular grid. Though the house looks complex and expensive to build, it is actually surprisingly simple.

5) Necessity Inducing Out-of-the-Box Creativity: Throughout history, rectangles and circles have been the dominant shapes employed in housing design. They’re logical, efficient, and easy to design/construct. But how do you put rectangular rooms into a triangular floor plan? What rooms do you place at the points of the triangle? How do you eliminate space wasted by sharp angles? Ultimately, we believe that having to rethink the traditional rectangular “house” and stretch our imaginations to fit all the spaces into a triangular footprint unleashed creativity and resulted in a surprisingly compelling solution—to the extent that we might ask: why not build triangular houses?

Making a Glass House "Green" | Eco-Attributes of the Triehouse

It’s not an easy task to create an environmentally-friendly glass house.

Traditionally speaking, houses with high amounts of glass consume lots of energy and are very costly to heat and cool—especially in extreme climates like Texas. Even low-E, insulated, double glazed glass is no comparison to thick, well-insulated walls. So what do you do if you have a picturesque site and want to showcase the beautiful views without paying big energy bills? How do you create the feeling of living in the trees if there’s a wall between you and them? Is it possible to make a glass house “green”?

We believe it is.

The Triehouse doesn’t have solar panels or high-tech “smart” materials. It’s built entirely of conventional materials which can be purchased anywhere. But it has a series of creative features which help to reduce energy consumption dramatically and make it environmentally responsible:

1) Saving Space by Smart Design: Many homes waste a lot of space due to poor design. One room is too small, another too big, another too wide, another not wide enough. It’s as if the designer never considered how the room would be furnished. There is also a lot of square footage dedicated exclusively to circulation (hallways, stairwells, corridors): often 10 to 12 percent of the floor area in large homes. From an environmental standpoint, this is very wasteful, and in the design of the Triehouse we sought to remedy this.

Instead of beginning with a house footprint and wedging spaces into it (as is often done with tract homes), we began by designing and dimensioning each room independently until it was perfectly suited for the client’s needs/desires. This ensured that there was no wasted space or shortage of space in each room. Then we arranged the rooms so that they fit together in a way that maximized views and privacy, minimized circulation, encouraged proper adjacencies, and fit into a footprint that wove within the trees. As a result, we were able to satisfy the entire program while reducing the size of the house by 400 square feet from the size originally requested by the client. We were also able to reduce the circulation space from 10+ percent to 2 percent of the floor area. Less building means less material, and less space to heat and cool over the life of the house—not to mention significant financial savings. Leaner = greener.

2) Making Glass “Green”: Not all square footage is created equally. A small space with solid walls on all sides can feel oppressive. But the same space—with glass walls or large windows overlooking beautiful views and bathed in soft natural light—can feel wonderful. Those who visit the Triehouse are often stunned to hear that the house is much smaller in reality than the size they would have guessed. This is largely because of the connection to nature and the expansive views from each room. Whereas a standard opaque wall creates a visual terminus in a room, a glass wall simply keeps the water and insects out. Though glass is less energy efficient as a building material than a standard wall, the visual enlarging effect it has on spaces can dramatically reduce the amount of square footage needed to make a space feel comfortable. Glass can be a real space/square footage saver. In this respect, when used carefully, glass can certainly be “green”.

3) Saving the Trees, and Being Sheltered by Them: By fitting in among the trees, the Triehouse not only protects the natural trees on the site, but also protects itself from the sun’s direct rays. Before designing the house, we measured the outdoor temperature in the direct sunlight versus in the shade of the trees, and found the temperature under the trees to be 20 degrees (F) cooler than in the direct sun. This means that on a blistering 100 degree (F) day, the temperature of the air around the house is only 80 degrees (F). That’s only a 5 to 8 degrees warmer than an average air conditioned room.

4) Light without Heat: The tree canopy not only cools the air around the house, but protects the glass walls and windows from direct sunlight. This keeps the heat from the sun’s light out of the house. The low-E glass also helps by keeping out most of the ultraviolet light.

5) Carefully Placed Windows: Windows are not all bad. They can provide natural light for the house and natural ventilation for cooling and circulating the air inside. Natural light is richer than artificial light—and it’s free. It also reduces the heat load on the building by reducing the need for artificial lights which produce heat. Thanks to many carefully placed windows—including clerestory windows in most rooms—it is possible to live and work in the Triehouse during daylight hours with little or no artificial light.

6) Natural Cooling: Sitting in a car in the hot sun with the windows rolled up is certainly unpleasant. Parking the car in the shade helps, but being able to roll down the windows so that the air can flow makes all the difference. Much in the same way, the Triehouse was designed not only to take advantage of the shade from the trees, but to be completely open-able to allow for natural cooling and ventilation. Every room has at least two operable windows (or sliding glass doors) placed on different sides of the room to allow/induce breezes to flow through the space. During Spring and Fall—as well as temperate mornings or evenings in the Summer—it is possible to turn off the central air conditioning, open up the house, and enjoy the natural breeze.

7) Evaporative Cooling: As a supplemental form of cooling in the hot summers, the Triehouse has an infinity pool carefully integrated into its design. Sure, the pool is great for cooling off with a swim in the summer. And it certainly enhances the view from inside the house. But the pool serves another critical function: cooling by evaporation. If you look at the floor plan, you’ll notice that the pool is centrally located so that the entire house wraps around it. You’ll also notice that the pool lies to the southwest of the house. This is because the prevailing summer breezes in this region come from the southwest. By placing the pool where it is, the outdoor air is cooled naturally through the process of evaporation before it ever enters the house. Not only does the shade from the trees reduce the temperature of the air (e.g., from 100 F to 80 F), but evaporation reduces it even more. Evaporative cooling is an ancient trick used frequently in India, but is often overlooked in Western architecture today.

8) Ultra-Efficient Air Conditioning: Though the house is flexibly designed with natural cooling in mind, there are times when air conditioning is necessary. But even the A/C system on the Triehouse is designed with efficiency and environmentalism in mind. Instead of running the A/C ducts through a hot attic (often 120+ degrees F), the ducts are run beneath the house where the temperature rarely exceeds 80 degrees F. This saves a lot of energy, and also allows for shorter duct runs which increases efficiency. Thanks to the shade of the trees and the house itself, it also means that the intake air is much cooler, which reduces the work the A/C unit has to do to chill the air.

9) Zoning: Another way the Triehouse reduces its energy consumption is by separating the house into zones for air conditioning/heating. Each zone is separated physically by hidden pocket doors, and has its own A/C system and thermostat. That way the owners only have to heat/cool the part of the house that is being used. The formal living room, dining room, and guest bathrooms—which are primarily used for entertaining—can be closed off from the rest of the house and kept at a higher temperature. The children’s bedroom “wing” is also separable from the rest of the house and on its own system, for when the children are away. In addition, the thermostats are all mobile/wireless and can be moved around the house as necessary to improve accuracy of measurement. They are also designed to recognize and respond to daily patterns of use (as well as motion) so they automatically know when to turn up/down or on/off.

10) Tankless Water Heaters: In order to reduce the energy required for heating water, the entire house runs on tankless water heaters, each located adjacent to the primary source(s) of use. Instead of heating a tank of water 24/7 as traditional water heaters do, the tankless water heaters heat water on demand only. The short runs from the water heaters to the source(s) of use also increases efficiency and means that the water stays hot as it flows through the pipe.

In the end, it’s not simply a sum of energy-saving ideas and systems that make the Triehouse “green”. It’s what the house stands for—and what it says to all who see it. This is a house literally built around the trees, designed to tread lightly on the land and not only preserve the natural environment, but showcase it. It’s a luxury home that proves that living and cooperating with nature is not only conducive with a luxurious lifestyle, but enhances it. Why conquer nature when we can simply cooperate with it?

"Less Gravity, More Green" | Structural Innovations

There are many structural innovations that work together to make the Triehouse not only feasible, but economical.

Foundation:
The soil in the Dallas region is very unstable, and almost every slab is doomed to crack. Pier and beam foundations are a good alternative, but with piers, bad soil means drilling 15 to 25 feet—which can be very costly. We realized that pier and beam was the only way to maintain the natural slope of the site, keep the trees, and protect the house (which lies near a floor plain) from flooding. But with so much drilling and pouring necessary for each pier, how could we make a pier and beam foundation economical? The house’s triangular footprint only made things more challenging.

In order to reduce the number of concrete piers in the foundation and increase the allowable spans of the foundation beams, we cantilevered both ends of every beam. This reduced the number of piers necessary to support the house by 40 percent—which not only cut the cost, but increased the elegance and "hovering" appearance of the structure. But with such long spans and cantilevers, the size of the beams required to support this became excessive and expensive. So we developed a creative new composite beam that cost only ¼ the price of standard beams. This not only reduced the material cost dramatically, but reduced the labor cost by eliminating the need for heavy machinery to lift the foundation beams in place onto the tall concrete piers, since the composite beams could be assembled in place from standard lightweight lumber. It also saved time and risk by eliminating the need for special order beams.

Shear Walls:
Glass has no lateral strength, and a house built exclusively with walls of glass would certainly collapse in a strong wind/hurricane. Most glass houses do not have this problem because they are built of steel, with steel columns, steel beams, and steel cables or X-bracing for lateral support. Steel is exponentially stronger and more rigid than wood. In fact, a steel cable can outperform an entire wall of wood. This is why a glass house with a steel frame can be so strong yet have almost no visible structure. But creating an “invisible structure” with wood is a challenging proposition.

Building Code requires that a house in the Dallas region withstand winds of 90mph, but the Triehouse was designed to withstand winds of 120+ mph. In order to satisfy the need for shear walls, extra strength plywood was used for the exterior walls, and many interior walls were sheathed with plywood as well. The rigid roof and floor diaphragms also add resistance. Fortunately, a triangle is the strongest shape in nature, and the triangular house footprint once again came in handy in terms of increasing lateral stability.

Windows:
Framing the large glass walls and picture windows in wood (instead of steel) was also a challenge. Large beams are necessary to support the roof across long spans. But they’re also expensive and unattractive. In order to increase the elegance and contemporary, gravity-defying appearance of the house—and to increase the allowable spans using smaller beams—many of the beams supporting windows were cantilevered in a fashion similar to the foundation beams.

Decks:
In order to allow trees to penetrate through the outdoor decks and to enhance the gravity-defying appearance of the house, the decks were all designed to cantilever from the house. Thankfully, the composite beams we developed allowed for the deck portion of the beams (subject to rain/weather) to be built with treated lumber, while the main span of the beams (protected by the house) were not. Since treated lumber is much more expensive than regular lumber and standard beams come either entirely treated or entirely non-treated (i.e., not half/half), this resulted in significant savings.

More structural explanations can be found in the FAQ section (below).

Creative Ideas for Cutting Costs

Where there is creativity, there are always ways to cut costs. We’ve listed a few ways we reduced costs below:

1) Conventional Materials, Used Creatively: Many architectural homes rely on grandness of size or exotic materials and finishes to make spaces elegant. The Triehouse is different. It relies almost entirely on nature for beauty, and simply nestles in the natural environment, frames the views, and accommodates the sun, wind, and trees in a way that makes otherwise standard spaces feel spectacular. It is built entirely of conventional materials, used in creative ways for increased efficiency and elegance.

2) Creative Engineering: There is no limit to how much creative thinking can cut costs. By cantilevering the foundation beams, we reduced the number of concrete piers required by 40 percent. By inventing our own composite beams (instead of using standard beams specified by the engineer), we cut the cost of the beams from $40,000 to $12,000 and eliminated the need for heavy machinery to put the beams in place. By designing the entire home under a small, simple, single-sloping roof, we cut the cost of the metal roof from $46,000 (for similarly sized homes in the neighborhood) to $19,000. By raising the house off the ground and running the HVAC ducts beneath the house, we shortened the lengths of ducts necessary, reduced the ambient temperature around the ducts, and increased ease of installation. By using a thick dual-layer water runoff system beneath the stucco (to prevent rot or mold), we reduced the amount of stucco necessary to cover the house by more than 30 percent. These are a few examples of how creative engineering kept the cost in check.

3) Efficient Floor Plan: By minimizing circulation space and unusable square footage, we were able to shrink the house footprint by 400 square feet and reduce the dedicated circulation space from 10+ percent to only 2 percent. So while the Triehouse costs slightly more per square foot to build than a standard tract home, it also reduces the buildable square footage by eliminating wasted space.

4) Energy Efficiency: We’re not interested in lowest first cost (i.e., lowest construction cost). We’re interested in lowest cost of living and highest long-term value. Many people do not consider that if energy bills cost $300 per month, then that’s an additional $108,000 paid over the course of the 30 year loan. An extra $5,000 upfront—or a creative strategy for natural lighting and cooling—might save $50,000 over 30 years. There’s so much money and energy to be saved in designing for lowest monthly cost, not lowest first cost.

5) Saving Dollars, Not Skimping Pennies: The largest savings in home construction occur in the early stages of design with big picture creativity—not by cutting corners or skimping on materials once the floor plan is developed. Too often designers and developers speed through the design process, then try to cut costs by changing materials and finishes during bidding. Instead of asking whether a particular room is even necessary, they’re asking for a lower price on the tile for the room. Instead of reducing the area of the roof by 30 percent with smart design, or adding insulation to save $1,000s each year in energy costs, they’re arguing pennies off the price of shingles. Thorough design at the right time pays for itself many times over.

6) Good Construction Manager & Clients: We owe a lot of the cost savings in the Triehouse to our Construction Manager (Luis Ospina, Yellowstone Builders, Inc.), who consistently brought in bids below market rates and kept everything on track. His creative solutions also saved a lot of money. We also owe a lot of the savings to our clients, who spent countless hours researching and sourcing the best materials at the lowest prices.

Frequently Asked Questions (FAQs)

Why does the house sit so high off the ground? What is a cantilever? Can I visit the Triehouse? Below are answers to a few of the most frequently asked questions:

Where is the Triehouse located?

The Triehouse is located in Parker, Texas, a small town in the greater Dallas metroplex. It is approximately 20 minutes north of downtown Dallas, which gives the client the benefit of “living in the country” while working in the city.

Can I visit the Triehouse?

The Triehouse is a private residence, and unfortunately, is not visible from any public thoroughfare.

If you would like to visit the Triehouse, please do not disturb the owners. You may direct your requests to us at Adia, and we will let you know if there is a tour scheduled in the near future. If you have an urgent or particular request, we will contact the owners on your behalf.

Why is the Triehouse so high off of the ground?

There are many reasons we chose to raise the Triehouse off of the ground. These are the main ones:

1) Privacy: A glass house only works if it satisfies the human need for privacy. We’ve all seen examples of buildings with curtains permanently drawn over the windows, or worse: foil or newspaper. Though the Triehouse appears to be alone in a forest, there are neighboring homes within close proximity on each side: close enough to overhear cell phone conversations. Most of the private areas of the house are 6’ to 10’ off the ground, meaning that the windows are 9’ to 15’ off the ground. In rooms with sliding glass doors which open onto private decks, the deck railing is an average of 12’ off the ground. This was done to allow the residents to enjoy expansive views without any concern about being seen from the outside. The high windows and deck railings limit the viewing angle from the outside, so that anyone walking near to the house cannot see in. If someone were to look from afar (at a point where the viewing angle was not obstructed by height), they would be too far to see anything with the naked eye, and there were would be too many trees blocking the view as well. By meeting the need for privacy, the residents can enjoy large windows and sliding glass doors in their bedrooms and even in their bathrooms—without fear of being seen.

2) Being “in the trees”: The client’s dream was to be surrounded by trees—and the entire house was designed for that. Although the view of trees on ground level is nice, it cannot compare with the view from above “within” the trees. On the ground you see many roots, tree trunks, weeds, dirt, etc. Up in the air you cannot see the ground: you only see branches, tree canopies, and sky. Gravity is gone, and it’s hard to tell whether you’re 5’ off the ground or 15’. Being up in the air makes all the difference.

3) Honoring the Natural Landscape: The site has a natural slope of about 9’ from one end of the house to the other. Rather than re-grade and flatten the land—which is not only costly, but changes the natural flow of water, requires uprooting trees, and damages root systems—we decided to leave the land as is and build the house as a single level plane above it.

4) Space for Systems and Storage: Most of the Triehouse does not have an attic. The roof and the ceiling are one plane, which allows for high ceilings, clerestory windows, and less labor/material to construct. So instead of placing ducts and systems in the attic, everything was placed below the house. By raising the house high enough that a person can walk beneath most of it, there is room for all the necessary mechanical equipment—as well as extra storage space. In a hail storm (very common in Dallas), it is possible to park half a dozen vehicles beneath the house for protection.

5) Elegant Elevations: A typical slab on grade foundation is not compatible with trees and roots—or hills for that matter. So we chose to use a pier and beam foundation…with a few improvements. Though building the foundation platform high off the ground is more difficult than building it 2’ off the ground (as in typical pier and beam construction), the cost of concrete and rebar to gain the extra height is minimal. It’s the drilling and the pouring 15’ to 25’ beneath the ground level that is complex/costly—not adding a few feet to the pier height above grade. At most it cost an extra $1.00 per square foot to add some height to the piers in order to raise the house high off the ground. But this paid for itself many times over in the extra space for storage and mechanical systems, the increased ease of plumbing/HVAC installation and repair, the reduced risk of flood or termite damage, the privacy and views gained by being high off the ground, and the elegant appearance of the house from the outside.

What it a cantilever, and why were they critical in the design?

A cantilever is a projecting structure (in this case a beam) that is supported only on one side. A diving board is a good example. Whereas most beams used in construction are supported on both ends, the majority of the beams in the Triehouse are supported only on one end (i.e., cantilevered).

If you look at the concrete piers holding up the house, you’ll notice that they are all pulled back about 3’ from the face of the building. You’ll also notice that many of the windows and glass walls in the Triehouse have corners with no column. Instead of stopping, the glass just turns the corner.

Though this was done partly to enhance the appearance and make it look as if nothing but glass is holding up the roof, it was primarily done to cut costs in a creative way. By cantilevering the beams above the windows, it was possible to reduce the size and deflection of the beams—which cut costs and allowed for more stylish, slender beams. Most houses with large walls of glass and long spanning beams are built of steel, which is stronger but significantly more expensive than wood. Cantilevering allowed us to achieve the elegance of an expensive steel home within the economical budget of a wooden one.

Cantilevering the foundation had two important benefits. The first is that it allowed for the house to be very close to the trees without harming the trunks and roots. You’ll notice that there are places in the house where large trees come through decks, or pierce the roof, or come within 2’ of the walls. If the foundation piers were directly in line with the walls of the house, this would not be possible. But by pulling them away from the outer edge of the house, we were able to sneak in as close as possible to the trees without harming them.

The second benefit is that by cantilevering the beams, we were able to reduce the number of concrete piers necessary to support the house by 40 percent. This is difficult to explain without diagrams, but it was a critical innovation in making the house affordable by cutting the cost of a standard pier and beam foundation almost in half.

Is it possible to build a smaller version of the Triehouse?

Yes, absolutely. We are actually in the process of developing a smaller (3 bedroom, 2 bath) version of the Triehouse, which we’ve tentatively dubbed “The All American.” The structural and architectural system developed for the Triehouse can be used for houses of any size. Our goal is to make elegant, eco-friendly architecture available to everyone.

Acknowledgements

We would like to thank the following people for their invaluable contributions:

The clients (who have requested their name be kept confidential): There could not have been more perfect clients to work with on a project like this. Tired of living in an uninspired tract home with large energy bills in a treeless subdivision, they wanted something different but weren’t exactly sure what. They were open-minded, excited about innovation, willing to try something unconventional, trusting, appreciative, and have such refined and elegant tastes. Innovation requires the right team, and we could not have done it without them. They were dedicated researchers and fellow out-of-the-box thinkers all along the way.

G. Goetz Schierle, Ph.D., FAIA: Structures professor, mentor, and friend, who preached cantilevers and taught that an understanding of structures & construction is the key for enabling architects to break barriers and dream/design outside the box.

Luis Ospina (Owner of Yellowstone Builders, Inc.), our faithful construction manager who embraced the unique/challenging design, helped us through the high learning curve, and saved $10,000s along the way.

Haleigh & Randall Stallworth, fellow entrepreneurs & visionaries, and faithful supporters & friends.

Jeff Cross, building systems & sustainability consultant, whose vast knowledge and experience helped to guide the Triehouse vision into reality—as well as the adiaHouse and MCDhouse before it.

And last, but certainly not least, we would like to thank the many talented builders whose dedication transformed concept into reality.