FRONTIER ZERO. Zero-Energy Houses for Wyoming. We are willing to work with you to develop full construction plans.

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1 We are willing to work with you to develop full construction plans Please contact us FIRST EDITION. MARCH Designs and all content 2015 by Jon Allen Gardzelewski, AIA and Anthony Denzer University of Wyoming

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3 Introduction Who would not like the opportunity to purchase a home with no electric and gas bills? That opportunity is now yours! BERG the at the University of Wyoming has created this catalog of home designs which can achieve Net-Zero Energy* on an annual basis. These designs are offered free for Wyoming developers, homebuilders, and citizens. *Note: This is not a guarantee. See Appendix A. Frontier Zero Approach The catalog includes a variety of sizes, types, and styles, to appeal to a wide range of Wyoming residents. We also sought to create designs that would address many economic levels. In general we want to create homes that will be attractive and contextual in a Western aesthetic, sympathetic to the Wyoming landscape and building traditions. Although a Net- Zero home can be built in any style, we do not use the catalog to promote styles, like Colonial, which are essentially foreign to the traditions of the place. We have also worked carefully to design the homes so that Solar PV panels are integrated into the architectural character of the homes, rather than tacked on to the roof as an afterthought. Working With Us If you would like to build a Frontier Zero house, we will work with you to customize the design for your site. We will also perform energy simulations based on your climate and construction-type to determine the best heating systems and how much solar energy (PV) is required. We can also help builders find subcontractors experienced in specialty areas such as superinsulated wall types, highperformance HVAC systems, and solar energy systems. For additional services, such as full construction documents ready for permitting, we may charge a fee or we may ask you to work with a local architect. For more on climates and construction types, see Appendices B & D.

4 Zero-Energy Houses: An Overview A Net-Zero house is defined as one which produces as much energy as it consumes on an annual basis. The basic procedure is: a) reduce the heating, cooling, and lighting loads as much as possible by architectural design and detailing; b) provide the remaining energy needs with on-site wind and/or solar energy. Is Net-Zero feasible? Absolutely. The examples illustrated on the right are from cold-climate locations similar to Wyoming, and they have been built at a reasonable cost. Wyoming is especially hospitable to Net-Zero houses due to the excellent availability of wind and solar energy, low cooling loads, and the effectiveness of superinsulation in reducing heating loads. The technical challenges to achieve these outcomes have been met for a climate like Wyoming (for example, typical houses built to Sweden s building codes can be heated with the equivalent of a hair dryer); the present challenge is to bring these accomplishments to the commercialization stage. The BrightBuilt Barn by Kaplan Thompson Architects and Bensonwood Homes, Rockport, Maine

5 Grand Teton Grand Teton model details 35 lot ; East or West-facing 1680 sq. ft.; Two levels. Optional basement. 3 bedrooms; 2-1/2 baths Estimated construction cost:* $243, ,000 Solar View First Floor 840 sq. ft. Second Floor 840 sq. ft. *See Appendix A. Note: This is not a guarantee.

6 Red Desert Red Desert model details 75 lot ; South-facing 1595 sq. ft.; One level. Optional basement. 3 bedrooms; 2-1/2 bathrooms May be designed for accessibility Estimated construction cost: $246, ,000 Solar View *See Appendix A. Note: This is not a guarantee.

7 Sweetwater Sweetwater model details 65 lot; East- or West- facing 2290 sq. ft. 4 bedrooms, 3-1/2 bathrooms Estimated construction cost*: $276, ,000 Solar View First Floor 1335 sq. ft. Second Floor 956 sq. ft. *See Appendix A. Note: This is not a guarantee.

8 Elk Mountain Elk Mountain model details 75 lot ; East- or West-facing 1830 sq. ft.; One level. Optional basement. 4 bedrooms; 2-1/2 bathrooms Estimated construction cost*: $262, ,000 First Floor 1830 sq. ft. Solar View *See Appendix A. Note: This is not a guarantee.

9 Medicine Bow Medicine Bow model details lot ; South-facing 2180 sq. ft.; Two levels. Optional basement. 4 bedrooms; 2-1/2 baths Estimated construction cost*: $274, ,000 Solar View First Floor 1250 sq. ft. Second Floor 930 sq. ft. *See Appendix A. Note: This is not a guarantee.

10 Sheep Thunder Mountain Basin Thunder Basin model details Shallow lot; North- or South-facing 1400 sq. ft.; One level. Optional basement. 3 bedrooms; 2 baths Estimated construction cost*: $230, ,000 Solar View Floor Plan 1400 sq. ft. *See Appendix A. Note: This is not a guarantee.

11 Big Horn Big Horn model details 50 lot; North-facing 1850 sq. ft.; Two levels. Optional basement. 3-4 bedrooms; 2-1/2 baths Estimated construction cost*: $255, ,000 Solar View First Floor 1000 sq. ft. Second Floor 850 sq. ft. *See Appendix A. Note: This is not a guarantee.

12 Jackson Hole Jackson Hole model details 60 lot ; East- or West-facing 2000 sq. ft.; Two levels. Optional basement. 3-4 bedrooms; 2-1/2 baths Estimated construction cost*: $255, ,000 Solar View First Floor 1100 sq. ft. Second Floor 900 sq. ft. *See Appendix A. Note: This is not a guarantee.

13 Lower Falls Lower Falls model details Narrow lot ; East- or West-facing 900 sq. ft.; One level. Optional basement. 2 bedrooms; 1 bath Estimated construction cost: $154, ,000 Solar View First Floor 900 sq. ft. *See Appendix A. Note: This is not a guarantee.

14 Fremont Peak Fremont Peak model details Irregular lot (end of cul-de-sac) 1800 sq. ft.; Two levels. Optional basement. 3-4 bedrooms; 2-1/2 baths Estimated construction cost: $252, ,000 Solar View First Floor 1300 sq. ft. Second Floor 500 sq. ft. *See Appendix A. Note: This is not a guarantee.

15 Gooseberry Creek Gooseberry Creek model details Narrow lot 800 sq. ft.; Two levels. Optional basement. 2 bedrooms; 1-1/2 baths Estimated construction cost*: $128, ,000 Solar View First Floor 420 sq. ft. Second Floor 380 sq. ft. *See Appendix A. Note: This is not a guarantee.

16 Appendix A: Costs Cost information shown has been prepared to illustrate potential construction costs in the Wyoming new home market. The estimates are approximate and do not represent actual quotes or guarantees. Actual costs may vary across local market conditions and individual builders and contractors. These estimates include: increased insulation and high efficiency windows unfinished basement PV system (proportional to house size) These estimates do not include: Land or lot prices Nonetheless, care was taken to create construction cost estimates that reflect current market realities. We gathered data from a number of Wyoming home builders including advertised base prices, square footage, and number of floors for a variety of models currently for sale that are similar to the models developed in this catalogue. Using statistical regression analysis, we estimated the relationship between base price per finished square foot, total home size, and number of floors using the models currently marketed by Wyoming home builders. We then applied these relationships to the models in this catalogue. Estimated costs per finished square foot decline with home size and vary between $178 per square foot for the smallest model and $103 per square foot for the largest. Because there is some uncertainty in these calculations, in the regression modeling, and in the actual costs a builder would incur, the construction costs for each model are presented as a range rather than an exact number. Net-Zero homes in Denver by New Town Builders marketed with monthly energy savings These homes sell faster than standard homes of the same type

17 Appendix B: Construction Types Frontier Zero houses are able to be customized to suit the local conditions and the preferences of the owner and builder. We can, on a case-by-case basis, perform specific analyses to determine the energy use for any given construction type, and compare with construction costs to make good decisions. The major considerations are: good insulation, airtight construction, and thermal mass. Best Practices for low-energy houses from Popular Science Generally we recommend: An unconditioned, ventilated attic space, with at least R-49 insulation in the ceiling. R walls, depending on the costs and climate. These walls may be: Standard 2x4 or 2x6 construction with exterior rigid insulation. Double-wall 2x4 or 2x6 construction. Structural Insulated Panels (SIPs). Insulated Concrete Forms (ICFs). The floor presents several alternatives: Slab-on-grade. This is best for passive solar heating. Crawlspace. Crawlspaces should be unconditioned and ventilated. Raised floors should be insulated to the same level as the walls. Basement. If a conditioned basement is included, it will increase the building energy use significantly and more PV will be needed to reach Net Zero. If an unconditioned basement is included, the raised floor should be insulated as in a crawlspace. All foundation walls and footings should have at least R-10 exterior insulation. All concrete floor slabs should have at least R-10 rigid insulation beneath.

18 (continued) For walls, ceilings, and floors, the effective R-value may be considerably lower than the nominal R-value if there are thermal bridges. Infiltration is of paramount importance. We assume tight construction, defined as 0.5 air changes per hour (ACH). This takes considerable effort on part of the builder, using a high-quality air barrier, paying careful attention to sealing seams and edges of openings, and minimizing penetrations. If the builder can achieve super-tight construction (0.3ACH), energy savings can be significant. Many designs have air-lock vestibules. All other exterior doors should have storm doors. Positioning trees as windbreaks can have a good effect on infiltration. There should be no pet-doors and no attic hatch (access attic through attached garage where possible). Ceiling can lights are not recommended. BERG can verify tightness with a blower-door test For thermal mass, slab-on-grade construction is preferred, as mentioned above. Additionally, we can help explore other options, such as: Interior mass walls, such as stone. Thin concrete floors on upper levels. Phase-change materials. Thunder Basin: Solar-heated air-lock entry; great for reducing infiltration

19 Appendix C: Heating Frontier Zero Homes are designed to take advantage of passive solar heating. With good envelope construction and proper architectural design, passive solar can provide up to 40% of winter heating needs. This is why Frontier Zero Homes have large amounts of south-facing windows, and relatively few windows on the north, west, and east walls. Frontier Zero Homes are designed for Air-Source heat pumps, which use electricity and refrigerant loops to create hot and cold air as needed. These systems are reversible, so they can be heaters or air conditioners, although most wellinsulated Wyoming houses rarely need cooling. Heating systems are rated by their Coefficient of Performance (COP). This is the ratio of heat output to energy spent. An ordinary gas furnace has a COP of about 0.9. An Air-Source heat pump may have a COP approaching 4. In very cold weather, Air-Source heat pumps work less efficiently. At temperatures below 0 F, the heat pump may not be able to keep up with the house s needs. In this event, the system includes electric resistance coils to heat the air directly. The COP is about 1.0 at these times. Passive Solar design admits the winter sun while avoiding overheating in summer. A backup heating system may be desired to address the possibility of grid interruptions. If this is a consideration, we recommend a wood or pellet stove, furnace, or boiler for backup heating. Some of these systems can be integrated with central air systems to distribute wood-generated heat throughout the home. Using wood for backup heat can be considered Zero-Energy if the solar energy system overproduces to compensate for the wood fuel. A Mini-split system (air source heat pump). Extremely efficient.

20 Appendix D: Energy Use Simulation We conduct energy modeling using Energy Plus simulation software one of the most innovative and widely used simulation engines available. Energy Plus simulates annual energy use with typical meteorological year (TMY) data sets derived from collected local weather data spanning 45 years (i.e., TMY3 data). As the typical year s weather generally doesn t exactly match that of any real year, the simulated results are not appropriate for accurately predicting a home s actual energy usage in a particular year. However, the simulation is a powerful way to evaluate the benefits of various energy conservation measures under typical weather conditions. The simulation model helps us to answer specific questions in finding the most economic path towards zero energy. We evaluate both standard and custom wall, roof, and window options, as well as different heating systems in finding the economic balance point between conserving and producing energy. The added costs for installing the best windows on the market, for example, is less cost effective than installing additional PV panels, or upgrading to a more efficient heat pump. Using simulation with collaborative cost estimating, we can find the sweet spot balancing cost and performance for a given location.

21 Wyoming Climate Zones These homes are designed for state-wide applicability in Wyoming. However, while the state is generally cold and dry, it is not uniform. For building energy use, the climate is usually characterized by Heating Degree Days (HDD) and Cooling Degree Days (CDD). A degree day is derived from the difference between the day s average temperature and an appropriate base temperature (usually 65 F for heating). So a day whose average temperature is 20 F has 40HDD. The total for the year provides a good estimate of heating needs. Cheyenne, for example, has 7326HDD, while Laramie has The ASHRAE climate zone classification shown below is based on the Degree Day formulation. Because there is some variability in Wyoming climates, Frontier Zero Homes may need to be fine-tuned to respond to specific conditions. We are willing work with individuals to adapt these designs to the needs of the location. Source: ASHRAE

22 Appendix E: Renewable Energy Incorporating on-site renewable energy, typically photovoltaics (PV), is necessary to achieve a net-zero residence. PV systems, which convert sunlight into electricity, are the most common distributed renewable energy system in the country, primarily due to their low maintenance (no moving parts) and easily predicted performance. Fortunately Wyoming has an excellent solar resource. Most of Wyoming is more productive for PV panels than Miami, FL (see map). PV costs have declined rapidly in recent years (see image; prices for panels only). A continued, but slower, downward trend is expected. Installing a residential grid-connected PV system in Wyoming is aided by the state s net metering and interconnection policy. The state law mandates that utilities, expect municipally-owned enterprises (e.g., Gillette, Torrington), allow the connection of systems less than 25 kw. In addition, the policy mandates excess energy production be credited to your account, either on a monthly or yearly basis. This allows homeowners to store electrons produced during the day for use at night, and in many cases carry excess balance from month-to-month. The cost effectiveness of residential PV is hindered by Wyoming s relatively low electricity prices, but declining module costs and the federal tax credit, which offers a 30% credit on systems installed through 2015, make a PV system s return acceptable to many homeowners. This is especially true for those who value price stability or the positive environmental attributes of renewable energy. Other renewable energy options include solar hot water and small wind, although solar electric is prevalent. Source: NREL UW Extension / School of Energy Resources offers an overview of residential renewable energy technologies, incentives, and available calculators BERG offers solar energy analysis to determine how much can be collected on your rooftop

23 Frontier Zero Partners Scott Kane, Creative Energies, Lander Adam King, King Engineering, Cheyenne Mark Attard, AE Building Systems, Fort Collins, CO Related Publications by BERG Jon Gardzelewski and Anthony Denzer, Put Wyoming s Sunny Disposition to Work Barnyards & Backyards (Spring 2014), Jon Gardzelewski and Anthony Denzer, Keep on the Sunny Side: Lower Your Utility Bills with Passive Solar Techniques Barnyards & Backyards (Winter 2014), Mahdokht Soltaniehha, Jon A. Gardzelewski, Gang Tan, and Anthony Denzer (2012). Passivhaus and Net Zero Energy Residential Designs in a Cold Climate: A Simulation Based Design Process for the Next Generation of Green Homes, SimBuild 2012; 5th National Conference of IBPSA USA [proceedings published online]. Jon Gardzelewski, Anthony Denzer, Gang Tan, and Mahdokht Soltaniehha (2012). Net Zero Residential: Feasibility and Microclimate Responsive Design for a Cold Climate, 2012 World Renewable Energy Forum/ ASES National Solar Conference [proceedings published online].