Gable Home: 2009 + SD / IL
The links below will lead you to educational information on specific subjects of the Gable Home. Our team members have put in considerable amounts of work, learning all the way, in order to get the best solar home.
- Passive House
- Structural Engineering
- Mechanical Engineering
- Electrical Engineering
- Interior/Industrial Design
- House Transportation
- Future of Gable Home
The primary concept of the Gable Home is to create a synthesis between innovative technology and vernacular Midwestern architecture. This synthesis results in a synergetic relationship between the two, creating an environmentally sustainable home of the future.
The design exhibits a strong preference for reused/reclaimed materials over the production of new material. The siding of the house was reclaimed from a barn being deconstructed in Rockford, Illinois. The decking material was salvaged from a demolished grain silo in Champaign, Illinois. Restoring and repurposing material from farm structures strengthened our design emphasis on local vernacular architecture.
In order to be used for the Gable Home, the barn siding required some restoration and preparation. Each board underwent a process of paint removal, sanding, re-sizing and painting before it could be installed on the Gable Home.
SILO WALLS TO DECKING
Our decking material previously served as walls for a grain silo. The grain silo walls were made of 2x6 dimensional lumber stacked horizontally. The walls were broken up into managable pieces at which time we acquired a sufficient amount for our needs. The process of repurposed this dimensional lumber was rather labour intensive. Each board required separation, sizing, power washing, sanding, and staining before being installed into transportable decking modules.
The architectural language of farm structures allow us to design with a clean and simple aesthetic. The decking, windows, siding, and roof were each sized to relate to each other and enhance the simple aesthetic of a barn.
The Gable Home was designed to meet Passive House standards, a rigorous performance evaluation that requires optimal performance and environmentally sensitive design. The house is highly insulated and incorporates advanced window design and installation technology. Such specifications reduce air infiltrations significantly and help the home act like a thermos, maintaining a comfortable, consistent indoor temperature.
WINDOW AND DOOR SYSTEM
High-quality, energy-efficient window and door systems were required in order to meet Passive House standards and achieve certification. All windows and doors were generously donated by Optiwin. The window systems were designed to meet Passive House standards and have an approximate U value of 0.15 Btu/h·ft²·°F
The structural frame of Gable Home is made of 3/4" laminated bamboo framing elements. The laminated bamboo was generously donated by Lamboo Inc. Lamboo offers 10 times the strength of typical framing wood and in this application, the minimal thickness signficantly reduced thermal bridging, which helped us achieve the energy efficiency required for Passive House certification.
The mobility of the home and the sensitivity of the competition site (the National Mall in D.C.) required a unique foundation design. By utilizing 2’x2’x6” concrete footings reinforced with structural steel bars, the load can be transferred to the ground, maintaining less than 1500 pounds per square foot pressure. In total, the home uses 20 footings, each equipped with optional steel plates (for leveling) and a steel “WT” section that will secure the house to the footing.
The mechanical systems are located in a loft above the bathroom. From this location, the mechanical system supplies fresh, conditioned air into the spaces and returns exhaust air to the exterior of the building. The mechanical system is a compact HVAC system which combines a number of heating and cooling tasks for greater energy efficiency.
The primary component of the mechanical systems is the Energy Recovery Ventilator (ERV). This system essentially captures cool air in the summer and warm air in the winter and transfers this energy to the fresh supply air, reducing the amount of energy required to condition the air.
The solar photovoltaic (PV) power system is designed from both a power generation and an aesthetic standpoint. A minimal design would ensure that the PV system supplied all the energy needs of house, but with minimal upfront cost. The team preferred to blend the PV system into the building design without sacrifice of architectural objectives. The solar array is placed at nearly the optimal angle for solar harvest, fills the southern roof space, and provides far more than enough power to balance the building energy.
The final design is the product of many back-and-forth tradeoffs on roof size, PV peak power capability, roof pitch, cost analysis, energy analysis, PV module technology, and ease of installation. SunPower SPR-225-BLK panels are utilized in the Gable Home. These modules are very efficient, reasonably priced and furthermore, due to SunPower’s proprietary production methods, they have a nearly solid black appearance that is aesthetically pleasing compared to conventional PV modules, which tend to have visible metallization and a degree of purplish tint. While energy balance can be achieved with a 6 kW system, the available roof space allows for mounting a 9 kW array.
CONTROL SYSTEM AND LIGHTING SYSTEM DESIGN
The design goal is to monitor and control the energy use in real time. Automated control of individual receptacles and switches will be provided. Additionally, the ability to monitor the power draw of every circuit in the house is also provided. LED light fixtures are employed due to their high efficiency. However, the amount of control we have on these light fixtures is limited considering dimming LED light fixtures is difficult. As a result, the controller for the lights is limited to switching them on and off. The switching is controlled by a series of INSTEON relay switches, which function as on/off switches. A touch-screen computer provides an easy to use graphical user interface to control the switches remotely.
The major determining factor behind the interiors scheme was to maximize the use of the limited interior space by achieving maximum functionality with minimum visual and physical intrusion. It was considered imperative to use compact appliances with good energy efficiency, consistent with the regular demands of the two likely occupants, but also with the requirements of the competition. The kitchen/living room area occupies a large proportion of the overall floor plan, but feels bigger because of the the high ceiling and large south facing windows.
KITCHEN AND LIVING
The kitchen/living room area occupies a large proportion of the overall floor plan, but feels bigger because of the the high ceiling and large south facing windows. The Gable Home is divided into three distinct zones; work space along the north wall, circulation along the center, and a leisure zone with seating to the south. Minimizing visual obstructions and hallway space allows the home to feel larger than it really is. Overall, the plan remains a simple exhibit of comfortable living within a very small footprint. All the furniture and fittings were donated by Crate and Barrel from their CB2.
In the living area, the TV is a rear- projection model donated by Samsung, a display technology which is more efficient than Plasma or LCD, in a slightly bigger cabinet. This display technology is now obsolete, driven off the market by the more compact flat-screens. The main speakers use drive units from the English company Lowther which produce 95dB/watt of electrical power, enabling realistic sound levels for movie viewing with a Class-D amplifier of only 15 watts output. All cabinetry comes as a subsidized donation from Valcucine, an Italian company with a long record of using durable and ecologically responsible materials and construction processes, as well as an inventive approach to kitchen ergonomics.
COFFEE TABLE = CHAIR
It was determined early on in the design that the required 8 seating places for the entertainment competition crowd the space in the dining area. As such, we built a coffee table that can "transform" into two extra dining chairs.
The bathroom is designed as a wet-room, enabling us to provide a wheelchair accessible shower and toilet in a 25 sq ft space. All bathroom fittings were donated by Kohler. The room has a shower wand for use by a wheelchair occupant seated on the toilet, or for hair washing at the sink, whilst the main shower is on the opposing wall. The room uses the best components in Kohlers range. The natural wood slatted floor enables water drainage into a tray below, whilst providing non-slip properties when showering.
The bed and nightstands were designed and built by students. The design intent was to create a simple and spacious design. The bed has a 12" cantilever to give the effect that it is floating and the underside of the bed is reserved for storage. Laminated bamboo donated by Lamboo Inc. was used to construct all furniture in the bedroom.
A major design component of the Solar Decathlon is the need to transport the Gable Home and all components to the National Mall in Washington D.C. There is a limited amount of time to assemble all the various systems and components, so much of the design took into consideration speed of assembly. The home will ship in three major components, the main module, the roof cap and accessories. The video of the home placement can be viewed at the video gallery page.
The main module of the home will transport as a single, enclosed unit, measuring 15’ 6” wide x 53’ long and 11’-10” tall. The home will be placed on a low-bed trailer supplied by our home manufacturer, Homeway Homes, which has a 16’ wide and 70 feet long capacity. The home will be placed on the truck using either a large crane or a series of pneumatic lifts, depending on the terrain and situation. By constraining our home to fit within the dimensions transportable by truck, the home can ship with all windows, drywall, fixtures, electrical siding and finishes in place. This will allow the team more time to concentrate on site-work, furniture and solar panels.
Due to our need to fit beneath bridges and federal shipping regulations, the maximum height of the home must remain below 14’-6” while on the truck. With a height of 30” for the trailer supplied by Homeway Homes, we had to design accordingly. This lead to the unique structural rib and frame section described earlier. Each roof cap will measure 14’ x 8’, allowing for easy transport on the back of the main module truck and simple installation. A crane will lift each section off the truck, place it on the roof and a rigging crew will secure it to place with large, 6” screws.
Future of House
The team is currently in discussion with a developer interested in placing the Gable Home at a permanent location. The planned location will be near the University where it can be studied and used by the community and students.