By Matt Baker
This summer, the Chicago branch of the USGBC, in collaboration with the McHenry County affiliate of Habitat for Humanity, hosted the Natural Talent design competition. The charrette was open to all university level students of any discipline and level and individuals five years or less out of school.
The competition’s parameters were simple: design a home for a suburban location to LEED standards while adhering to a strict budget. The contest aimed to emphasize the need for affordable, sustainable communities that keep residents and revenue within the community, as well as to empower students and young professionals to become future leaders in the green building movement.
On August 26th, the panel of judges–Laureen Blissard of LTLB Development, Tim Heppner, Tom Jones of Habitat for Humanity McHenry County, Susan King of Harley Ellis Devereaux, Peter Landon of Landon Bone Baker Architects, Rashmi Ramaswamy of Shed Studio and John Sieck of Reservation Homes–decided the winners. The top three finalists were awarded a cash prize and the first place winner will be registered for and provided travel support to Greenbuild, USGBC’s national conference, where they will present their design to compete against other regional winners.
The winning design by Troika, dubbed the SYMbiotic house (or SYM house) attempts to overcome the traditional one-way relationship between occupant and dwelling by designing an environmentally responsible home that inspires a mutually beneficial, symbiotic relationship.
Construction begins on site with the concrete pylons and a poured concrete “wrapper,” a continuous band of concrete that contains the active systems of the house. The house rests on a poured concrete plinth, which is elevated above the ground on the concrete pylons. All concrete is sustainably produced and the pylons cause minimal disruption to the site.
Meanwhile, the fabrication of the walls begins off-site. When the walls and other prefabricated components are completed, they are assembled at the site. Prefabricated exterior panels and wall units are designed for ease of construction and deconstruction using simple, affordable materials. Interior walls use a minimal number of prefabricated wood stud walls to divide interior spaces. Inside, radiant floor heating, low emissivity double pane windows and eco rock interior finish comprise some of the home’s sustainable features.
The SYM house uses a unique butterfly roof system for maximum water conservation. Where the inclined roof planes come together, the wrapper gathers rainwater runoff and directs into a cistern within the house. The water collected from the inclined roof planes is redistributed for use in the toilet and the gardens. Greywater can also be used for the garden. The roof assembly is standing seam metal roofing overlaid with photovoltaic panels and evacuated solar tubes which provide hot water for the radiant floor heating.
The house takes advantage of passive daylighting systems such as solar gain in addition to the active solar collectors. Wood louvers block the high, hot sun of the summer but allow all light to penetrate in the winter when it is needed most.
The simple material palette was chosen for its longevity, ease of construction, and affordability. The benefits of concrete, wood, metal, and glass extend beyond budget and building. The site uses native plants, and almost all materials are porous. The concrete pavers for the driveway are recycled. These materials work well together ecologically—many are recycled, recyclable and found locally. They yield long-term savings and do not have any harmful effects on the health of the inhabitants.
Traditionally, the occupants of a house are consumers; the house gives energy and water, and after a number of years it no longer meets the owners’ needs so they leave it for the next “parasitic” residents. The SYM house attempts to change this notion by offering the occupant a reciprocal relationship with the house. With some basic education, the owner can take charge of the solar gain, natural ventilation and landscape management. In turn, the increased efficiency of the house will yield dramatically lower operating costs. By assuming an active role in the cycle of the construction, systems and landscape, the owner will have a greater sense of attachment to the house. This symbiotic relationship ultimately ensures a higher quality of life, which is a common goal of the USGBC and Habitat for Humanity.
Not every family will occupy the SYM house in the same way. Because it’s prefabricated, modular construction, the home can adapt to a variety of needs. The carport also provides flexible space for extra uses. Empty nesters may incorporate a green house, master bedroom, home office and family room or fitness room while a family with one child could manipulate the space into a master bedroom, child’s bedroom, home office and car-port.
The GreenLEEDers, comprised solely of students from The Illinois Institute of Art, began their design with site planning. Careful placement of the home took into account facilities within the surrounding mile, including public transportation, parks, cultural amenities, retail and schools.
The 1,200 ft2 home begins with insulated concrete walls, including 100% recyclable material, no CFCs and non-toxic resources. Despite employing only standard parts, the walls use less waste than traditional framing, are rated between R-22 and R-40 and offer a continuous thermal envelope. The walls are fireproof and provide stable temperatures, quick installation, increased interior floor space and reduce heating and cooling costs.
Topping the structure is a green roof with superior span and load-bearing capabilities that lacks elements that can be damaged by moisture. The system can be installed flat or at an angle to aid drainage. The roof’s vegetation offers stable roof temperatures, which results in lower heating and cooling costs. The system also reduces roof deterioration caused by extreme temperature change and improves storm management.
Outside, permeable pavers reduce installation costs of drainage systems, increase water quality, reduce stormwater runoff and flooding and reduce erosion. Water catchment systems and rain gardens also reduce stormwater runoff, reducing the demand for city water. A white cement concrete driveway has a high solar reflectance that helps abate the urban heat island effect. A compost machine provides fertilizer for the gardens and aids soil health.
Brise soleil helps shelter the kitchen doors and patio area from the summer sun, keeping the interior temperature low. In addition, a trellis system made from recycled content helps provide shading and insulation by promoting foliage growth.
Quad-Lock insulated concrete walls have great insulation properties, control noise, reduce heating and cooling costs and have a longer lifecycle than traditional framing methods. Ultratouch Natural Fiber insulation is made from 85% post-industrial cotton fiber and is 100% recyclable. Gorilla Wrap house wrap is made without formaldehyde and contains 25% recycled glass. Recycled content drywall is made using synthetic gypsum, a by-product of a pollution-control process employed by coal plants.
Several systems are employed to conserve water. The Trispa showerhead by Oxygenics saves up to 30% on water, and is ADA compliant. Caroma’s dual-flush toilet allows the user to select a small (0.8 gallons) or a larger flush (1.6 gallons). An on-demand water heater helps lower energy costs by not continuously heating water in a reserved tank.
Energy Star fans are 50% more efficient than standard fans, aid air flow, help control temperature and contribute to utility bill savings. Choosing other Energy Star appliances can save about 35% less energy than their non-rated counterparts. Energy costs are further offset by using GE residential solar modules which supplement the electricity coming in off the grid. The Solatube Solar Star attic fan is an environmentally friendly attic ventilation solution that requires no electricity.
The GreenLEEDers team chose several sustainable finishes, such as the zero VOC Benjamin Moore Natura paint. Two types of tile employing different resources were chosen: Showercork Mosaic Tiles are made from rapidly renewable, post-industrial wine corks and Sandhill glass tiles are made using 100% recycled glass. Glass is also recycled into the Vetrazzo countertop surfaces, set in cement. Other surfaces come from Ecotop Surfaces, comprised of 50% FSC certified post-consumer recycled paper and rapidly renewable bamboo fiber.
A number of green flooring and wall covering options were also designed into the house. Teragren bamboo panels have greater hardness, durability and stability than maple and are manufactured with formaldehyde-free adhesives. InterfaceFlor’s Fresh Start carpet line is made using a commercial plastic derived from corn, and is backed with recycled material and post-consumer recycled content. Finally, the American Barn Company recycles lumber from old barns to create custom furniture and flooring.
[3rd Place ]
Perhaps the most novel aspect of the Sergeant Funkhouser house is the detached wind tower. Directional vents at the top of the “Windcatcher” cooling tower can be adjusted to allow for optimal reception of McHenry County’s prevailing west winds, which is cooled in an underground tunnel and fed to the center of the house where it is distributed to each space.
Sheathed to match the house, the wind tower’s support structure doesn’t appear out of place with its surroundings. Wood-grain decking made of a recycled plastic material is another sustainable technology that blends in nicely with the rest of the house. An entire wall of standard sliding glass doors further combine sustainability with aesthetics and create an open indoor/outdoor living space with the back yard in summer months. Awning transom windows provide ample natural daylight and ventilation in every room in combination with secure views through full-height windows.
The gable roofs on the house and detached garage allow solar hot water panels or photovoltaic panels to be mounted directly to the habitat house for on-site power generation. Both the solar panels and wind tower are designed with the flexibility to accommodate the final siting of the house and its orientation for optimal solar and wind gain.
Outside, ornamental prairie grass, found natively across the plains of Illinois, requires little water and will naturally grow to form a dense screen. Sedum, periwinkle and galliard are hardy plants that will add texture and interest to the landscape.
Open grid pavers allow rain water to soak and filter through while providing a cooler hard surface area. The rain garden provides further stormwater runoff abatement and drains into an underground cistern.
Kitchen countertops are made from recycled paper, pressed with cashew oil resin into a smooth surface that the resident can use like any other countertop surface. Cabinetry is made with a formaldehyde-free substrate and sustainably harvested wood veneers. All appliances are high-efficiency.
Two sustainable options are presented for flooring. The carpet is made from 100% recycled content, while hardwood flooring is of rapidly renewable, durable and abundant bamboo. In the bathroom, the accessible walk-in shower is outfitted in slip-resistant etched recycled glass tile.
Hinged glass breezeway walls connect the main structure to the detached garage. The insulated double wall system can be locked in the open position for more air circulation in the summer, or closed for an enclosed winter space.
Along with the breezeway and “Windcatcher,” operable windows alleviate HVAC needs by drawing in cooler fresh air down low, while upper clerestory windows circulate warm air back out at the roof peak via a stack effect.
To NWBR, Habitat for Humanity is uniquely positioned at the forefront of the effort to provide affordable and sustainable housing to people in need. Designing a sustainable home which is also affordable is not impossible. Environmentally responsible design does not need to rely on expensive technologies to be sustainable. Sustainability in its purest form uses simple, responsible, money-saving design techniques to build a more efficient and economical home.
Sustainability begins on the outside of the house. Native grasses and native vegetation require little to no maintenance or watering. Permeable pavers in walkways and driveways reduce the heat island effect and aid in stormwater management. The land drains stormwater towards the rear of the property where a rain garden allows the water to dissipate into the earth naturally. Rain garden fauna provide natural habitats for local species and a beautiful backdrop for a rear yard. Low-water sod, reclaimed wood decking and shade and fruit trees finish off the open space.
Rainwater is harvested from the roof, stored in a cistern and can be used for garden or lawn irrigation. A simple system that runs off a residential water heater can provide in-floor radiant heat at low cost and further water saving. This system is modular and simple to install, a key component to NWBR’s designs as this is a proposed Habitat for Humanity house and would be erected largely by volunteers.
Several systems are in place to maximize utility conservation. The spatial design of the home divides it into a public zone and a private zone, which can be controlled separately for more efficient mechanical heating. The house is heated by a radiant floor system which is comprised of plex tubing laid in a pre-routed plywood subfloor.
The home’s form is also designed to exploit natural ventilation, drawing cool air from the low windows while driving warm air out the high windows. The home’s design makes mechanical air conditioning irrelevant.
Shade trees to the south of the property, along with shading devices on the south facade windows reduce solar gain in summer. Clearstory windows with a roof overhang allow enough indirect light in to naturally illuminate the space while shading the house from the brunt of the sun’s summer force. But the overhang is designed to let direct light in for necessary solar gain in winter. Trellis plants along exterior walls also passively cool the home in the summer.
It’s the insulation that really make the heating and cooling of the house so efficient. R-20 extruded polystyrene wraps the outside of the frame while four inches of R-19 batt insulation fills the stud cavities. Two-stud corners with drywall clips increase economy of material and decrease air penetration at the corners—one of the worst heat leaks for any house. Insulated concrete forms not only add to the house’s efficiency, they make building foundations volunteer-friendly.
Building materials were selected for recycled content and recyclability. The design also features reclaimed wood and engineered wood floor with recycled content. Stone found on-site was incorporated into the design. A fly-ash concrete foundation wall uses recycles industrial by-products, but the material has also been shown to strengthen concrete and increase durability. The house was also designed to reduce construction waste, especially considering the volunteer work.
Finally, the NWBR team did not design in a vacuum. While fully recognizing that the work would be completed by volunteers of varying skills, they also fully integrated their design into a community. Pedestrian-oriented neighborhoods have a discernable center, whether it’s a main street, a public park or a downtown. The neighborhood’s density is also important; NWBR’s ideal neighborhood is compact enough for local businesses to flourish and for public transportation to run frequently. Mixed incomes and mixed uses ensure that businesses, schools, parks and residences are all located within proximity of all. And plenty of parks and open spaces mean there is an abundance of public spaces for meeting and recreation.
It was the out-of-the-box thinking that garnered Contain Yourself an honorable mention. Well, almost out of the box; this project makes judicious use of recycled steel shipping containers in conjunction with a collection of conventional stick frame construction and prefabricated assemblies. These materials result in an end product that is affordable and nearly indestructible. The modified containers are mold proof, fire proof, termite proof, structurally superior to wood framing and along with various other components come together to create a system that is predicated on cost savings, construction time savings and energy conscious priorities. Sixty percent of the building is efficiently assembled in a controlled shop environment.
The house is oriented favorably on site, with the greenhouse facing south whereby its heat flows into the interior simply by opening the sliding doors. Stack affect is achieved by compactly modeling the double-storied living and sleeping space. The containers are further subdivided into separate temperature zones, thus reducing the energy requirement significantly.
The metal roofs are pitched predominantly less than thirty degrees in order to retain snow build-up while the PV panes are oriented forty-five degrees for desired solar gain. In the winter, the snow acts as insulation, while promoting efficient drainage to the water collection zone. Increased roof insulation is used in order to reduce heat loss.
Very little artificial lighting is needed during the day; natural light is plentiful due to window placement and open floor design. All windows are double-glazed. Operable windows are placed low and high in the bedrooms in order to ventilate optimally for multiple temperature conditions.
Another unique feature to this home is the glass bottle walls. Glass bottles are easily recycled, but the light they emit as a wall element can be breathtaking. These unfinished “breathing walls” naturally diffuse air and water between the interior and exterior. The units are constructed of concrete form made from mineralized wood chips and Portland cement, making walls that are healthy, environmental, durable, easy to construct and cost-effective. The small ends of the bottles are placed outward and capped to prevent moisture accumulation and are given a slightly downward slant.
The glass bottle walls work in concert with radiant floors. There are small pores at foot level, called floor air channels, as vents for the passive cooling system. The holes are disguised as they follow the pattern of the glass bottle gridded units on the outside of the house, letting cool air into the crawl space located beneath the house.
The modular green roof system is a cost competitive alternative to traditional built-in-place green roofs. The roof is composed of a series of preplanted modules made of recycled plastics that can easily be placed directly on a roof. Traditional built-in-place systems, which often require new roof surfaces, protection mats, drainage sheets, etc., are frequently more expensive.
Green screens act as shading devices and privacy barriers, in conjunction with a readily available found building material: shipping pallets. The pallets have been reinvented as horizontal shading devices at the south-facing container glazing.
The house employs radiant concrete flooring. One benefit of under-floor radiant heating is that temperatures are higher at floor level and decrease toward the ceiling, resulting in more comfort at lower temperature settings. The designers also recognize the ceremonial place a wood-burning fireplace can have in the home, and have included an EPA “clean burn” approved high-efficiency stove in the central gathering space.
Semi-permeable, recycled bricks create less stormwater runoff. The bricks are arranged for efficient shoveling of snow in the winter months. The line of bricks are filled in at high-traffic zones to accommodate wheelchairs better than other natural paving options.
Most ground temperature variation occurs in the upper two feet of earth, so the top two to four feet of the foundation is insulated with rigid foam along the perimeter to disconnect it from fluctuating upper soil temperatures. The lower part of the foundation is not insulated. This system allows the home’s thermal mass glass bottle walls to dissipate heat during the summer and absorb and retain heat when it is cool.
Domestic hot water is the second highest energy cost in a typical household. A solar hot water production system is used to provide energy to meet seventy percent of hot water needs, even during the winter months. Tankless hot water heaters also reduce energy consumption.
By combining passive planning with construction techniques, the total heating energy requirement of this house is reduced by about forty percent when compared to standard house construction. In a well-insulated house, the size of the heating system can be smaller than
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