Sustainable Design Achievements

Our mission is to be a catalyst for positive and lasting change leading to healthier environments and communities.

Sustainable Design Achievements

Building Placement and Siting

The Guest House building was positioned on the campus in such a way as to shield it from harsh predominantly north and west winds of the winter, ultimately resulting in reduced energy consumption. Maintaining close proximity to the office building, The House and Wingspread reduces the amount of service circulation necessary to support routine daily building function and minimize utility connections and infrastructure extensions.

Proper Building Configuration

The segmented-angular configuration of the Guest House building avoids a direct north-south orientation, which reduces extreme thermal differentials in the building mass/volume, thus reducing fluctuations in energy demands from one end of the building to the other. This ultimately results in greater internal environmental control and reduced energy consumption. The orientation toward the pond takes advantage of cool breezes in the summer and provides wonderful views of this prairie environment from the majority of the guest units and public spaces.

Sustainable Building Materials

The Guest House building utilizes as many "natural" materials as possible (for example, wood, stone, brick, ceramic tile, etc.) in the structural frame, the exterior of the building and the final interior finishes. Laminated wood products were employed for the primary beams in the Great Room and LVL's (laminated veneer lumber members) were utilized as supports throughout the framing system. Wood framing (including 2" x 6" studs, I-joists and trusses) and wood sheathing make up the entire super-structure of the building. Natural stone (slate) was used in the lobby, at the west entry porch, at the east terrace and as part of the pedestrian path system (granite cobbles). Slate has also been employed in the public restrooms as both flooring material and lavatory counter surfaces. Ceramic tile was used in the guest bathrooms. Wood flooring and ceilings were employed in the Great Room and bamboo flooring was used in the pantries in the guest wings. Operable casement and fixed window units were made with wood products as were most of the interior and exterior doors. Natural wood materials (as opposed to plastic laminates) were utilized for the trim and casework elements throughout the facility.

Healthy Building Materials

Efforts were made to consider and select building products made locally (to avoid energy consumption through transportation), made from recycled materials (such as the I-joists and LVL's, and the sub-base for asphalt pavements), or made with non-polluting processes in their manufacture. Most of the building materials originate from the state of Wisconsin. Only a few specialty items were ordered out-of-state.

Tightly Constructed Building Shell

The exterior envelope of the building consists of six-inch deep wood studs fully insulated with R-21 fiberglass blankets along with wood sheathing and a Tyvek wrap to prevent air infiltration. A moisture barrier prevents condensation. The lower portion of the building utilizes a four-inch brick face while the upper portion utilizes a Portland cement plaster (stucco) treatment. Each cladding material serves to further enhance the airtight and watertight integrity of the building envelope, thus reducing energy consumption and moisture penetration. The concrete roof tiles, while providing a complimentary aesthetic appeal, also serve to reduce the heat loss and cooling load in winter and summer seasons. The attic of the hipped roof building is insulated with 10-inch thick R-30 fiberglass batts and a moisture barrier. Surface glass area was held to less than 17 percent of the total vertical envelope, thus reducing heat gain/loss and overall building energy consumption.

Abundant Natural Light in the Building

The use of insulated (thermally broken) double pane clerestory windows employed extensively throughout the building serve to admit generous amounts of natural light into guest units, operational spaces, circulation paths and gathering areas, which help reduce the need for additional artificial lighting and energy consumption. Large amounts of insulated double pane glass units along the east facade at the Great Room provide both dramatic views of the pond and the surrounding natural habitat, as well as abundant natural light.

Energy Efficiency

In addition to the energy efficient building envelope and HVAC systems employed throughout the building, the design includes broad roof overhangs that serve to cut down summer heat gain, solar glare and reduce the overall cooling load required in the summer, which results in reduced energy consumption. Other factors, such as the low flow toilets, urinals and shower heads, along with the high efficiency condensing water heater, help to reduce the amount of water usage and energy consumption throughout the plumbing distribution system. The absorption dual effect gas fired chiller serves to reduce energy consumption in the cooling season. The total heat recovery of exhaust air, along with the radiant coil heating system in the guest unit floors, contribute greatly toward reduced energy consumption in the heating mode. Control mechanisms, such as the variable frequency drive (VFD) pumps (for hot water radiant heating circulation) combined with the direct digital control (DOC) computer system, serve to reduce the overall energy consumption by automatically controlling plant operation and eliminating wasteful consumption in unoccupied spaces. High efficiency ballasts and lamps, LED lamps in egress lighting, low mercury lamps and automated lighting controls all serve to reduce the amount of electrical power consumption through the facility.

A Building that is Whole Systems Designed

The design of this facility was undertaken with an "integrated systems" philosophy. Each of the design, engineering and construction disciplines participated in the early conceptual planning phases of both the building and site design to produce a facility that: 1) respected the environment, 2) capitalized on available amenities, 3) satisfied the functional and operational requirements, 4) targeted energy efficiency and 5) reduced/eliminated waste. Opportunities for sustainable design and the use of renewable resources were examined early on so that alternative solutions could be considered, evaluated, adopted or dismissed depending upon their ability to satisfy the criteria set forth above. Optimal value engineering occurred early in the planning and design phase to help reduce and compact the overall building footprint, consolidate building functions and minimize the impact of the facility on the campus. A variety of mechanical system options were considered and evaluated for life cycle cost as well as comfort, acoustics, maintenance and efficiency prior to selecting the final designed system.

Site Work

Site Preparation

Site surface water run-off was secured with silt fencing. Erosion control methods conformed to the Wisconsin Best Management Practices.
Significant efforts were made to locate and protect existing trees and native plants.
Clearing/grubbing of existing vegetation was limited to specific utility and driveway paths.
Natural land forms were respected and/or restored to assist in natural drainage toward the pond. Drainage swales and overland flow paths were utilized to the maximum extent practical. The final grading plan minimized the amount of disturbed soil and vegetation by maintaining existing grade contours to the extent possible, preserving vegetation and root structure for large tree and shrub specimens.
Minimal numbers of substantial trees were removed to accommodate new construction/site circulation.
An existing tree remained while the foot bridge was built around it for pedestrian circulation.
On-site storage areas were utilized for excavated materials to avoid transportation energy usage.
Existing utilities were abandoned in place, minimizing waste and unnecessary excavation.

Site Design

Existing asphalt pavement was pulverized for re-use as base under new pavements.
Topsoil was stripped and re-used on site.
Surface water management was accomplished through very limited use of drainage structures or pipe. Creation of a drainage swale extension that appeared as a small ravine and landscape feature. The ravine returns this part of the site to a pre-development drainage pattern that allows water to flow through the ravine to the pond. Areas in the ravine flatten out to encourage water infiltration. Native vegetation in the ravine and swales will help water quality.
The majority of the pedestrian and light service vehicle paths were constructed of unit concrete pavers and stone, which have a much longer life than cast-in-place concrete or bituminous asphalt pavements.
Portions of the site were restored to natural native grasses, reducing water and chemical usage. Replacing traditional high maintenance bluegrass turf with Fescue turf and prairie plantings reduces the amount of mowing necessary (to once a year) and needs no fertilization or watering.
Parking areas were minimized and surrounded with natural landscape and trees for shading.
Extensive additional plantings to the site are native. This provides habitat, increases diversity and perpetuates continuation of native genetic material, all of which are factors in a sustainable environment.

Building Assemblies

Concrete and Stone

The use of cast-in-place concrete with fly ash as an additive reduced the overall material cost, along with the embodied energy to produce the concrete and its raw material content.
Utilized naturally quarried stones (limestone, granite, slate, etc.) for the pedestrian pathways, porch entry, east terrace, lobby flooring, brick wall capstones, lavatory counters and fireplace cladding. Most of this material was quarried within the region and available through local yards.
Precast concrete planks were utilized in long span areas where the load/span and structural member depth precluded the use of traditional wood framing. This was considered a more energy efficient choice over structural steel, composite metal deck and concrete fill because of the reduced embodied energy required to solve the span problem, along with the ability to erect precast members regardless of weather conditions.

Wood

Used pre-assembled wood roof joists, LVL (laminated veneered lumber) floor beams and wood truss joists. The truss joists, in particular, are seen as an efficient use of less desirable lumber or "weed trees" in the industry.
Use laminated wood beams for Great Room roof support and at foot bridges and service bridge.
Bamboo flooring material was employed in the guest pantries. Bamboo is considered a highly renewable wood resource.

Glass

The building was designed specifically to take advantage of natural daylight through the extensive use of clerestory glazing. The clerestory glass is generally positioned under broad roof overhangs to reduce solar gain and glare, yet admit generous amounts of natural light. Operable casement window units provide natural light, views and an opportunity for fresh air exchange. Glazing areas were organized to capitalize on views, reinforce architectural themes, and at the same time, minimized to reduce heat loss/heat gain. The total glazed area of the building (including all fixed and operable window units and all glass doors) is less then 17 percent of the total vertical wall surface area of the building envelope. This design achievement helps reduce energy consumption throughout the facility.
Used aluminum clad wood windows with thermally broken double pane glass and good insulation value.
Specified windows with low shade coefficients (low emissivity) and high visible light transmission.
Used operable casement windows at guest units and reading alcoves.

FURNISHINGS

Furniture and Fabrics

Significant elements of the guest room furnishings are manufactured by Harden, a company that owns its own woodlands and sawmill operations, including the bed headboard and footboard, the TV armoire, and the writing desk. Harden's woodlands are intensively managed and harvested on a rotational 15-20 year cycle. They are active members of the National American Tree Farm System. The forest is a renewable resource, and with proper management, can continually supply high-quality forest products. Fabrics utilized on the furnishings consist predominantly of natural materials: wool, silk, cotton, linen and/or leather. Very minor amounts of synthetic materials were used for fabric stability.

Floor Coverings

All of the oriental rugs are made from natural wool and silks using only natural organic vegetable dyes as opposed to synthetic dyes.
The walk-off mat at the main entry employs a natural material known as "coir" made of sisal-like fiber.
Natural cherry and bamboo floor coverings were used in the Great Room and pantries respectively.

MECHANICAL AND ELECTRICAL SYSTEMS

Plumbing

Specified low flow fixtures for toilets (1.6 GPF), urinals (1.0 GPF) and shower heads (2 GPM).
Employed drift control cooling tower. This prevents water evaporation when no cooling is required.
Specified high efficiency condensing water heater (96 percent efficient).

HVAC

Utilized absorption dual effect gas fired chiller. Utilized a gas fired chiller versus electric allows reduction of CO2 production, as well as reduction of the operating costs (and energy consumption). “Dual effect” means that the chiller has heat exchangers that improve cooling generation efficiency almost twice that of a single stage chiller. In addition, the gas fired chiller is CFC or HCHC free refrigerant.
Specified total heat recovery system for exhaust air. Outside air is pre-heated during heating cycles and pre-cooled during cooling cycles by exhaust air at heat exchangers. Heat exchangers selected for the project are "fixed plate" type so there is no risk of potential re-circulation and they have up to 80 percent efficiency.
De-coupled the outside air system in the guest unit wing. This provides space ventilation and tempering without the need to run heating and cooling equipment at individual rooms, which reduces noise, improves comfort and saves on energy consumption.
Provided compensating hood (for exhaust) in the kitchen. This minimizes the amount of treated space air exhausted through the hood.
Utilized a low temperature hot water heating system with a high efficiency condensing boiler. This improves boiler efficiency up to 96 percent, while providing better space temperature control.
Employed radiant floor heating in the guest units and reading alcoves. This provides a lower cost for general space heating, improves comfort for the occupants and reduces equipment noise.
Specified Variable Frequency Drive (VFD) on the recirculating pumps. This reduces energy consumption by the pumps during partial load conditions.
Provided automated direct digital control (DOC) control systems. This level of automation improves control of HVAC system equipment, reduces overall operational costs, reduces energy consumption and improves comfort levels.
Specified two-stage fan control at cooling tower. This allows for reduced energy consumption under partial load conditions and reduces noise levels, especially during night time function.
Utilized ventilation rates at about 1.5 times the code required to improve room air quality.
Utilized separate filtration of outside air system to enhance air quality. This allows filtration of outside air separate from fan coil units at individual spaces.
Specified continuous exhaust at guest unit wings to promote positive air flow and improve quality.

Electrical

Utilized high efficiency ballasts and lamps. This lowers the power output with improved lighting output.
Used LED lamp sources at all egress lighting to reduce power consumption.
Utilize lighting fixtures that conserve energy such as low mercury lamps.
Maximized day lighting conditions to minimize electrical consumption.
Incorporated automated lighting controls to reduce energy consumption.

 

Guest House At Wingspread

Sustainable Construction Practices

The goal of the on-site construction team was to develop construction practices that would result in as close as possible a "Zero Waste" environment. To this end, the team focused on the three "R's": reduce, reuse and recycle.
The reduction portion focused on effective ordering of materials so that excess quantities were kept to an absolute minimum. Whether this pertained to lumber lengths, plywood layout, insulation quantities or paint quantities, contractors were coached on being careful of the most effective approach to accomplishing their work and reducing the amount of material required.
The reuse effort focused on finding ways to reuse extra or leftover materials on-site. If there was no use on-site, was there a reuse opportunity elsewhere in the community.
Finally, the recycling program was structured around attempting to eliminate, to the greatest extent possible, all un-sortable and un-recyclable materials.
With these as the strategies, listed below are some of the more significant things that have been done from an on-site aspect:
All trees and shrubs that had to be removed were mulched onsite. The materials were stockpiled for The Johnson Foundation to use on walking paths throughout the grounds.
All excess soils were left onsite, thereby reducing fuel consumption and exhaust emissions from trucking to an offsite dump.
Where a major sewer utility had to be run, numerous large evergreen trees would have to be cut down. Instead, the contractor bored under the tree line to preserve the natural environment.
A comprehensive recycling program was established as part of the construction manager's "Zero Waste" program. Recycling containers were provided for all major products, including concrete, steel, plastics, wood, drywall, insulation, cardboard, paper and glass. This program was emphasized each week during the job and foreman's meetings.
Most of the concrete pavement removed was reused as walkways at locations in the area.
Removed asphalt pavement was taken to a crushing facility for reuse in roadbeds.
Much of the structural floor framing incorporated composite I-joists and laminated beams that are made from recycled materials.
Special controls were put in place to manage the disposal of chemicals used on-site, such as paints, solvents and adhesives.
Plastic pails were used onsite and given to workers for reuse later at home.
Wood materials for framing were ordered in lengths to minimize cutoff scrap.
Lumber cutoffs were reused as blocking in walls.
Cutoffs from carpet installation were taken to a recycling center.
Scrap insulation was collected and used in small void in the exterior envelope instead of throwing it out.
Lunch debris was sorted down to the paper bags, plastic lunch bags and candy wrappers and put in the appropriate containers.
All cardboard was collected into a recycling container for recycling.
Scrap concrete was placed into recycling containers to be crushed for reuse under slabs and pavements.