This new house was designed and hand built entirely by the owner as his first major project after graduating with a Master in Architecture degree from the Harvard Graduate School of Design. It is located in the Mojave Desert near Joshua Tree, California. As a result of its passive solar design, the house is able to heat and cool itself year-round, with no external energy input from traditional HVAC systems. In many ways, this house is the antithesis of Le Corbusier’s concept of a house as a “machine for living in”, as it is highly site-specific, extremely energy efficient, does not rely upon HVAC systems for temperature control, and nearly every element was designed and hand crafted specifically for this house. The project took nearly eight years to complete as all of the construction was done by the owner/architect himself. No contractors, sub-contractors, or daily helpers were involved.
Identifying the Design Problem What attracted me to this location was the dramatic landscape, the inexpensive land, and the climate. I felt that these qualities would provide an ideal spot to build a house that would serve as a laboratory, or test case, for a variety of ideas and emerging technologies that I wished to explore. Principle among my many interests was a desire to investigate the potential of passive solar design. In addition, while I am passionate about architecture, it pains me to witness the despoliation of the landscape and the resulting ecological costs, both short and long term, that o# en result from new construction. I enjoy tough design problems, so all of this seemed to be fertile ground for investigation. Upon moving to California in 2003 one such problem that presented itself was the fact the fact that most houses in the Mojave Desert rely upon traditional HVAC systems for heating and cooling throughout the year. ! e annual energy and " nancial expense required to operate such systems can be astounding when outside temperatures seasonally % uctuate between 15-120 degrees fahrenheit. I wanted to investigate whether it would be possible to design and build a house for this extreme environment that would passively self-regulate, so that a comfortable interior temperature would be maintained year round without relying on traditional HVAC systems at all. If successful, the bene" ts of such a design would be many: • ! ere would be no operating expenses for heating or cooling for the life of the house. • ! ere would be no mechanical equipment to maintain, service, or replace. • Such a reduction in energy consumption would reduce the carbon footprint of the building. • All of the above would result in drastically reduced life-cycle costs of the building. • ! e money saved through such increased e$ ciency could result in an increased standard of living for the bene" ciaries. • If the design principles were employed on a large scale, say that of a town or city, it would reduce local energy consumption, much of which still comes from non-renewable resources. How the design problem was solved ! e design challenge was met by employing a passive solar design strategy. While I had studied the topic for some time, this was the " rst time that I was actually able to put the principles into practice. As I designed the house, I was able to test the e$ cacy of each decision by running the design through EnergyPro energy analysis so# ware. ! e design works extremely well, and neither air conditioning nor heating are needed in any but the most extreme of temperatures. ! e passive solar principles employed are: proper geometry and orientation of the building; high thermal mass; proper insulation; solar control through calculated eave depth; tactical placement of glazing; an evaporative cooling pool; and an earth berm on north side of the house. An active solar hot water system provides domestic hot water and supplies water for radiant % oor heat. In the event of no sun there is an on-demand hot water heater. In brief, the aforementioned principles were applied as follows:
• Proper Geometry and Orientation ! e house is narrow and long, with the long axis oriented east-west. ! ese properties serve to maximize solar gain in the winter and minimize it in the summer. • High ! ermal Mass Material and the “! ermal Flywheel E" ect.” A key to e& ective passive solar design in the desert is utilization of materials that are high in thermal mass, like concrete. ! ese materials support a phenomenon known as the “thermal % ywheel e& ect.” With the thermal % ywheel a& ect, material of high thermal mass acts as a storage medium for thermal energy. When called for, thermal energy is automatically stored or released from the thermal mass, helping to keep interior temperatures stable • Tactical Placement of Insulation Because a majority of thermal energy transfer tends to occur through the roof plane, this roof has been insulated to R-42. ! is dramatically cuts the amount of unwanted heat gain in the summer and heat loss during the winter. • Solar Control ! rough Calculated Eave Depth ! e eaves of the roof plane play an important role in controlling solar gain. ! e depth of the eaves are calculated to maximize solar gain during the winter and minimize solar gain during the summer. ! e eaves allow sunshine to penetrate the entire living space during the winter, yet keep the same space fully shaded during the summer. • Tactical Placement of Glazing ! e majority of the windows in the house are situated on the south elevation and glazing is minimized elsewhere. ! is placement optimizes solar gain and minimizes thermal loss in winter. Skylights are not employed anywhere, as they are notoriously ine$ cient. • Tactical Placement of the Garage Volume ! e volume that contains the garage is placed at the far western edge of the building. ! is placement allows the garage facade to take the brunt of the a# ernoon sunshine during long summer a# ernoons, rather than the living space of the house proper. ! is e& ectively insulates the western edge of the house from the deleterious e& ects of the summer sun, such as unwanted solar gain. • Evaporative Cooling Pool ! e swimming pool functions as a large evaporative cooler in the summer months. As south westerly breezes wa# across the surface of the swimming pool, a pleasant micro climate is created in the patio area. On summer evenings, the patio doors are opened and this cool breeze helps to lower interior temperatures. • Earth Bermed North Facade ! e house is built into the side of a hill. E& ectively, the north elevation of the house is bermed. ! is earthen berm adds both insulation value and thermal mass to the north facade of the house, thereby reducing thermal energy loss or transfer and air in" ltration. Notable Design Details and Use of Space, Materials, and Technology Notable Design Details • ! e key to the high e$ ciency of this home is it’s passive solar design (i.e., geometry, orientation, arrangement of spaces, materials, glazing, pool, earth berm). Inexpensive materials, coupled with thoughtful passive solar design, result in drastically reduced power bills. Even with all of the glass, the house exceeded California’s Title 24 energy e$ ciency requirements by over 50%. • ! e house is nestled into the hillside landscape, it is not set atop the hill. Construction of a more conventional home would have necessitated an enormous amount of cut and " ll to create a %at pad upon which to build. ! is would have destroyed the intrinsic beauty of the site. ! e bermed design allows for preservation of much of the landscape. • ! e house is designed to be disassembled to allow for eventual re-use/recycling of materials. For example, the slate shingles are attached with stainless streel screws, not copper nails. • ! e low concrete retaining wall that surrounds the patio and pool area functions as a cropping device. Whenever occupants are sitting at chair height, whether inside or outside, the wall crops the entire foreground from view. ! is cropping action makes neighboring houses disappear from view, giving the illusion of being very isolated. • ! e swimming pool functions as a large evaporative cooler. ! e presence of a large body of water creates a micro-climate in the patio area, helping to lower interior temperatures in the summer. When the prevailing southwesterly summer breeze passes over the pool, the temperature of the air is lowered by evaporation. As this cool breeze wa# s through the open patio doors in the evening, the temperature in the house slowly drops, hour by hour as the concrete % oor slab gives up the heat that it has absorbed over the course of the day. In the morning, all the doors are closed. ! e house remains cool, but gradually warms up by the end of the day, when the doors will be reopened and the cycle will begin again. • Even though a lot of concrete and glass are utilized in the build, the house is still perceptually warm, not cool, due to sensitive manipulation of these materials as well as the selection of contrasting, but complimentary materials. • ! ere is a focus on furniture-grade wooden case work and cabinetry throughout the home. ! e warmth, re" nement, and relative so# ness of these built-in elements provides welcome contrast to the cool, raw, and hard surfaces of the un" nished concrete and slate. • ! is house was designed speci" cally for it’s particular context for numerous reasons: increased energy e$ ciency; decreased maintenance; and greater harmony with the natural environment. • ! is project best represents my current interests and abilities as a designer and builder: • A preference for residential work, due to the intimate scale. • Design problems that are clearly stated and design solutions that are clear, simple, well thought-out, and well-detailed. • A preference for experimentation and for the practical application of theoretical knowledge. • Design solutions that are driven largely by the immediate context. • A preference for a modernism that is warm and tactile, rather than cool and sterile. • A preference for a modernism that is modest in scale, cost, and material, but rich in aesthetic appeal, energy e$ ciency, and comfort. • A strong interest in sustainability and the thoughtful application of passive solar design principles. • A passion for cra# smanship; for constructing work that is extremely well built. Notable Spatial Features • ! e house has a very spacious and open % oor plan. ! ere are no doors, except for the bath rooms. • ! e house feels much larger than it’s actual square footage due to the abundant glass which connects each interior space to an adjacent outdoor space. • A movable kitchen island provides for a % exible kitchen/dining/living plan. ! e island can be arranged in a linear fashion, like a bu& et, which allows the dining table to be placed between the kitchen and the living room area (as shown in the photos). Alternatively, the island can be arranged in either a square or L-shape, with the dining table placed between the kitchen island and the sliding glass doors to the south. ! is results in a larger living room area and an eat-in bar at the island. • A disappearing Shoji screen pocket door provides % exibility for the center room. When the Shoji screen divider is concealed within an adjacent wall, the room is entirely open in plan. When the Shoji screen has been slid out from it’s concealed pocket, the center room is closed o& , allowing it to act as a more private space, such as a bedroom. • ! e entire north wall is a series of side-by-side closets. ! is wall of closets enables the adjacent hallway to act as a multi-functional space. In addition to providing pedestrian circulation, the hallway space also provides abundant storage and conceals a roll-away o$ ce, laundry facilities, clothes and linen closets, a library, and a mechanical closet. ! is compact arrangement helps to declutter and organize the interior and the vast expanse of wooden casework warms the entire space. Incidentally, this closet wall also serves as a concealed HVAC plenum for the back-up air conditioning system and it also increases the R-value of the north wall. Notable Use of Materials • Most materials are common and utilitarian but they have been cra# ed with the greatest care and attention to detail. ! is makes a great di& erence in the energy e$ ciency of the building and in the perceived quality of the build. • ! e hardy nature of the materials used, both inside and out, result in a house that requires virtually no maintenance. • Slate roo" ng shingles are employed as exterior wall cladding and this cladding is carried inside to be used as an interior wall " nish. ! is strategy eliminates the need for painting, adds thermal mass to the interior, and aids in blurring the distinction between inside and outside. • Drywall is largely eliminated. Instead, " ne casework of Vertical Grain Douglas Fir lumber is employed. • ! e majority of " nishes used throughout are of the no/low VOC and water-based variety. • ! e concrete counter tops are made of 75% recycled content/blast slag. • As the house is in a seismic IV zone, earthquake resistant design principles were employed; high-mass material is kept low to ground, lighter materials above. A simple wooden roof diaphragm and shear walls are inexpensive and e& ective means of resisting seismic forces. • Materials were selected on the basis of cost, availability, durability, aesthetics, and thermal properties. • Inexpensive concrete dominates as it provides excellent thermal mass, which is key to the passive solar design. • Stained concrete % oors throughout provide radiant heating and cooling for the house. ! is is quiet, comfortable, and e$ cient. Notable Use of Technology • Hot water is provided by an active solar hot water system with a propane on-demand hot water heater as back-up. • Low-e insulated glass is employed throughout. • High e$ cacy lighting (LED and % uorescent) is used for a majority of the house. • Occupancy sensors are used for bath lighting; dimmers are used on any incandescent lighting. •Wooden I-beam (TJI) and Timberstrand framing members. • Hydrophobic glass coating on shower doors makes them very easy to clean. • ! e passive solar design principles employed are low-tech, but very e& ective at reducing energy use.
