1 Introduction

If societies are to reduce greenhouse gas (GHG) emissions by 80 percent or more by mid-century, zero net energy (ZNE) and positive energy developments will be required strategies for success. The California Public Utilities Commission (CPUC) has in fact called for all new residential construction in the state to be ZNE by 2020 [1]. Building of this sort generally combines extreme energy efficiency with active generation of renewable energy (see chapters by Rajkovich et al and LaRue et al). Undertaking such development at a neighborhood scale is particularly desirable in order to bring a large number of ZNE buildings online quickly and to take advantage of district-wide systems design and economies of scale. Yet few such neighborhoods currently exist anywhere in the world. The University of California, Davis’ West Village, a new neighborhood for 4,200 students, faculty, and staff that opened its first phase in 2011, is intended to be the first large-scale ZNE development in the United States. It is a landmark project that, while still in the early stages, serves as an important model for community-scale ZNE development.

The number of ZNE neighborhood-scale developments in the world is still very small, and there has been relatively little systematic evaluation of their performance. The first and perhaps best-known example is the Beddington Zero-Energy Development (BedZED) in the London borough of Sutton. Designed by architect Bill Dunster and the BioRegional Development Group, BedZED opened in 2002 as a mixed-use, mixed-income development of 82 housing units along with commercial space, a daycare center, and exhibit space. The project combined highly energy-efficient construction with passive solar design, a small-scale combined heat and power plant initially burning wood from municipal tree-trimming (considered to be a carbon neutral fuel), and a green transportation plan emphasizing walking, cycling, and use of public transport. An initial evaluation in 2003 found that BedZED housing units used 88 percent less energy than the British average for space-heating and that residents used 25 percent less electricity than average [2].

Other examples of neighborhood-scale, very-low-energy development include Hammarby Sjostad, a development in Stockholm expected to include 10,000 apartments housing 25,000 people when completed in 2016. Although not ZNE, the project aims to produce about half the energy it uses through photovoltaic panels and an efficient district heating system burning waste to produce energy. Vauban, a new neighborhood for 5,000 residents on the site of a former French military base in the German city of Freiburg, includes 100 units built to “passive house” standards, with no active heating or cooling systems, and 59 “plus energy” homes. The Kronsberg district in the German city of Hannover also includes 32 passive houses.

Masdar City, a new community for up to 50,000 people currently under construction near Abu Dhabi in the United Arab Emirates, is perhaps the world’s most ambitious project aiming for ZNE status. In addition to energy efficiency measures, the project is expected to include large-scale solar power plants, wind farms, and geothermal energy. In the United States, a number of ZNE buildings have been built, but the largest neighborhood-scale ZNE development previous to West Village appears to be the partially built Green Acres subdivision of 25 upscale homes in the Hudson River Valley town of New Paltz some 85 miles north of New York City.

At UC Davis, West Village planners did not initially have a ZNE goal in mind. This objective emerged in the middle of the design process in part due to rapidly growing concern about climate change in California at the time. The zero net outcome was made possible by a creative public-private partnership, the forward-looking policy context in the state, institutional leadership at the University of California, and grant assistance from state and federal sources. Through its evolution and current operation, West Village helps illustrate the opportunities for ZNE development at the district scale, as well as some of the challenges facing such projects.

Section 2 discusses the background of the project and the process that led to its ZNE configuration, emphasizing procedural, institutional, and geographic factors that contributed to the project’s development. Section 3 describes the energy efficiency measures that made West Village more than twice as efficient as required by California’s already-stringent Title 24 building code. Section 4 describes the development’s renewable energy strategies, principally employing PV, and section 5 discusses the project’s other sustainability elements followed by the conclusions and what can be learned from the West Village example.

2 Background and Context

West Village is a new neighborhood for an eventual 4,200 residents on the existing campus of the University of California, Davis. This college town of about 65,000 people is located approximately 15 miles west of Sacramento in California’s Central Valley (Figure 12.1). Initially opened with apartment housing for 800 students in 2011, the entire first phase of West Village will consist of apartment housing for approximately 1,980 students. Student apartments are typically designed as two and four bedroom units in three-story buildings, with additional apartments on the upper floors of four-story, mixed-use buildings surrounding a central village square. The first floor of the these mixed-use buildings at the village square is lined with approximately 45,000 square feet of dining, retail, and office space.

As the urban activity hub of West Village, the village square also includes a student community center with recreation and study spaces, and a community college center – the first of its kind on any University of California campus. Rounding out the mixed-use community will be 343 two-story, single-family homes for sale to UC Davis faculty and staff, operating on a model of capped appreciation intended to keep the housing affordable for future generations. A second phase of West Village is expected to include additional apartment units and single-family homes (Figure 12.2).

The layout of West Village is an integration of three main planning strategies. In line with principles of the New Urbanism, the community includes a grid-like network of streets and mixed-use public spaces designed to optimize sociability, walkability, and effective transportation. Secondly, as an extension of the local planning model in the City of Davis, the community includes an extensive greenway system that doubles as a stormwater drainage network and a comprehensive off-street and on-street bicycle network. Davis prides itself for being the most bicycle-friendly small city in the United States. And third, to take advantage of local climate factors, the layout of West Village utilizes long east/west streets to optimize solar access and capture summer cooling breezes from the Sacramento River delta to the southwest of the site. Parking is provided at a ratio of three spots for every four apartment residents, located on the periphery of the site to allow uninterrupted bicycle and pedestrian access to apartment courtyards. Single-family homes are served by alley garages and streetfront visitor parking.

Planning for West Village began in 2000, after citizens of Davis approved a ballot measure preventing any future development on agricultural land or open space without voter approval. This severe growth constraint meant that private developers were unlikely to be able to provide substantial additional housing in Davis for UC Davis anticipated growth in faculty, staff, and students. The university was also concerned at the time about rapidly escalating housing prices. As part of a planning process to forecast campus needs, university planners put forward a variety of growth scenarios. Several scenarios included building a substantial new community on university-owned land, while others left staff, faculty, and students to find market-built housing in other cities and commute to Davis. The university held a series of workshops on such options with members of the Davis community in the early 2000s, engaged consultants such as well-known ecological designer Bill McDonough to help the community imagine a positive framework for growth, and prepared a long-range development plan (LRDP) and associated environmental impact report (EIR) by 2003. In addition to accommodating substantial growth in the teaching, research, and student services programs of the university, project goals included providing affordable housing for students, staff, and faculty. By choosing to develop a substantial community on university land, the campus reduced the negative environmental effects on air quality and transportation systems caused by the commute scenarios, and created a diverse, walkable community close to existing development on campus.

Energy objectives became more central to the planning of West Village in the mid-2000s due to state actions, rising public and professional concern about climate change, and the opening of multiple energy institutes on campus. Specifically, the signing of Executive Order S-03-05 by Governor Arnold Schwartzenegger in 2005 – committing the state to reducing greenhouse gas emissions 80 percent by 2050 – and legislative passage of AB 32 in 2006 – setting a 2020 target of reducing emissions to 1990 levels – provided major catalysts to public and professional interest in climate change. With California committed to becoming a global leader on climate change by the mid-2000s, officials at institutions such as the University of California began considering how they might assist this effort and develop green technologies and skills on their own campuses.

Although energy research had long been a strength of units within UC Davis such as the Department of Civil and Environmental Engineering and the Institute of Transportation Studies, the university established a number of new energy-related centers in the 2000s that became important resources for West Village planning. These centers included the following:

The initial technological and financial strategies for dramatically reducing energy use at West Village arose from a project advisory group convened by the newly formed UC Davis Energy Efficiency Center in 2006, with additional consulting assistance provided by the Davis Energy Group. This effort produced a set of increasingly aggressive energy efficiency ‘packages’ to lower demand. Encouraged by the prospect of deep reductions in energy demand through investments in efficiency, the project team began to pursue strategies for supplying all remaining energy demand through renewable sources. Modeling by the Energy Efficiency Center estimated base-case electricity consumption for the multi-family buildings at 13.8 kWh/sq ft/yr if built to 2008 California Title 24 standards. The modeling shows the energy efficiency package proposed by the center then reducing that amount to 5.6 kWh/sq ft/yr, a 58 percent reduction. For the single-family houses, modeling showed base case consumption to be 16.2 kWh/sq ft/yr, falling to 5.7 kWh/sq ft/yr with the deep energy conservation measures, a 65 percent reduction. The analysis indicated that total electricity use for the entire first phase of the project, including commercial spaces, the community college, and common area lighting, would be 23,295,000 kWh/yr, which could be reduced to 9.803,600 with aggressive energy efficiency improvements, a reduction of 58 percent [3]. Such data gave project planners optimism that renewable sources could then meet the remaining electricity demand, including up to 5 MW of PV, fuel cells run on biogas from a biodigester producing up to 300 kW, and a 1 MW battery (Figure 12.3).

During this time planners also secured grant funding to reduce project energy consumption from multiple sources. Grant sources included the following:

Pacific Gas & Electric (PG&E) and Chevron Energy Solutions provided assistance during this period as well. Actual construction of West Village began in 2008 with initial work on apartment housing for about 800 students in 315 apartment units, plus the community college facility serving about 2,400 students, and the village square mixed-use buildings. The university desired to build this central core of the neighborhood in the initial phase to create a heart to the community and a home for community-serving facilities. After this portion of Phase 1 opened in 2011, apartments rented quickly, and construction began on additional student housing units. The real estate market crash beginning in 2008 delayed development of the for-sale single-family homes; it is hoped that construction of that phase of West Village will begin as soon as the market recovers.

UC Davis did not have the capacity to construct the project from university funds, allocating most capital funds toward educational rather than residential buildings. The West Village community was conceived from the onset as a partnership with a private developer in order to finance and construct the project. Selected in 2004 through a request-for-qualifications process, West Village Community Partners (WVCP) is a collaboration of Denver-based Urban Villages, which has extensive experience in constructing walkable communities of similar scale to West Village, and San Francisco-based Carmel Partners, with significant experience financing and managing multi-family housing communities. UC Davis expended approximately $17 million to bring utilities to the border of the site, an investment that will be recouped through land lease payments from the developer and future homeowners. With a 65-year ground lease agreement with the university, WVCP anticipates a total investment of approximately $280 million to build out Phase One of the project. The financial model for the project was designed to place no financial burden on residents of West Village. In practice, the additional costs for energy efficiency investments and solar panels are recovered by the residents’ “energy bill.” The bill, in actuality, is not for power consumed, but to pay back the cost of efficiency and green power installations. The West Village breakthrough is to accomplish this redirection of funds towards SNE at no greater cost to the resident than the “business as usual” scenario.

Like other projects West Village is located within a specific geographical, political, and institutional context. Understanding this context and the development process is essential in order to determine its replicability and lessons for other mixed-use communities. First of all, the relatively mild climate of California’s Central Valley greatly affects building energy consumption, especially for natural gas (far and away the primary heating fuel in California). Since winter temperatures rarely touch freezing, energy needs for heating are far less than in many other parts of the world. Winter is California’s rainy season, but average annual precipitation is only 19 inches, and abundant sunshine makes passive solar building architecture relatively effective at further reducing heating needs. Summers are hot, with daily high temperatures averaging 94 and 93 degrees, respectively, in July and August, leading to high demand for air conditioning and correspondingly high electricity load on summer afternoons. Generally clear summer skies facilitate photovoltaic production during those hours, making Davis (like much of the American Southwest) an ideal environment for photovoltaics (PV).

Also, Davis is located in the part of the Central Valley closest to the Golden Gate, the natural gap in the state’s coastal ranges leading to San Francisco Bay. Although Davis is some 70 air miles from the Golden Gate, cooling evening breezes from the Pacific Ocean often reach the town in warm weather – the “Delta breeze” – further reducing air conditioning needs especially if buildings are designed to capture those cool breezes through effective window placement, the provision of operable windows, and ventilation fans. So West Village has utilized many design and energy efficiency strategies to take advantage of its geographical context. The watchword of the project became “First Reduce, then Produce” – optimizing benefits from community design, passive solar orientation, active energy efficiency investments, and only then, renewable energy production on-site to cover the radically reduced energy demand. The political, cultural, and institutional contexts of West Village are important as well. As previously mentioned, the acceleration of state, regional, and local climate change planning within California beginning in the mid-2000s established an atmosphere in which institutions actively explored strategies to reduce greenhouse gas emissions.

Even before, student activism had led the UC Board of Regents to adopt a Green Building Policy in 2003 requiring that campus buildings at least meet the equivalent of a LEED “Certified” rating. In practice, many recent UC buildings have exceeded this standard, achieving certification at Silver, Gold, or Platinum levels. The City of Davis also had a tradition of ecological development dating back to the 1970s, epitomized in particular by the Village Homes development that pioneered neighborhood-scale passive solar design, albeit in a relatively low-density, primarily residential format (e.g., [4]). The city is also known for some of the most extensive bicycle infrastructure in North America, for a very extensive greenway system, and for strong land-use policies to prevent sprawl and provide a mixture of housing and commercial facilities in each neighborhood [5]. In 2005 the city was the first in the United States to receive “platinum” bicycle friendly community status from the League of American Bicyclists. Davis residents, including many UC Davis administrators and staff, were thus inclined to be favorably disposed toward forward-looking green building projects.

Equally important, the University of California is not subject to municipal land-use planning approval for university-related growth, reducing the impact of community opposition that can often emerge as an insurmountable obstacle to development. University staff did seek to coordinate as much as possible with local citizens, elected leaders, and municipal staff. Campus planners conducted an extensive set of public workshops in the early 2000s and downsized the project substantially in response to neighbor concerns, also establishing a buffer of open space between West Village and the nearest residential neighborhoods in West Davis. These efforts pleased some city constituencies, but did not stop other neighborhood groups from contesting the adequacy of the EIR through litigation. Although the university prevailed in the lawsuit, this process set the project back about a year. If city permits had been required for development, similar neighborhood opposition would certainly have arisen, so the university’s special status quite likely saved the project from a lengthy and highly contentious permitting process.

3 Energy Efficiency Strategies

The cornerstone of ZNE strategies at UC Davis West Village has been energy efficiency. Project planners realized that only by greatly lowering West Village energy demand below California’s already-strict Title 24 standards through an array of energy efficiency strategies would it then be possible to consider meeting ZNE goals with renewable technologies. Energy efficiency measures were modeled as a package for different types of structures; the proposed measures produced a 65 percent saving for the single-family homes, a 58 percent savings for the multifamily structures, a 50 percent savings on common area lighting, and lower levels of savings for commercial and institutional building space [6].

Energy strategies at West Village evolved considerably during the decade between project conception and the opening of Phase 1, and it was only through flexibility and creative action by the university, the developer, energy-related institutes at the campus, outside consultants, and granting agencies that the project could consider attaining ZNE status. Passive solar design was part of the strategy from the beginning, but a major rethinking of goals occurred in 2006, when campus planners commissioned the UC Davis Energy Efficiency Center and faculty from the Graduate School of Management to develop an initial roadmap to reducing energy demand through energy efficiency. This strategic thinking enabled the university to apply for and obtain $7.5 million in grants from the previously mentioned sources to plan energy and conservation systems. This funding, much of it only available to research institutions, enabled intensive studies on energy demand, efficiency strategies, energy infrastructure design, and financing, and proved essential in developing ZNE concepts. Consultants and industrial partners such as SunPower, PG&E, Chevron Energy Solutions, Energy & Environmental Engineering, and the Davis Energy Group provided additional assistance in the following years, for example, by providing models to help calculate energy savings or production from various proposed features.

Energy efficiency performance in the West Village structures is achieved primarily through added insulation, radiant barrier roof sheathing, solar reflective roofing, high efficiency lighting fixtures, high efficiency Energy Star appliances, and high efficiency HVAC units. Exterior walls use 2″×6″ framing to give them added thickness to accommodate the additional insulation. Floors include an additional ½″ of gypcrete to increase thermal mass. Roofs benefited from both R-49 blown insulation and radiant barrier roof sheathing. Extensive hard-wired fluorescent or LED lighting in units, with vacancy sensors, reduces the need for occupants to add their own less-efficient lighting fixtures. The UC Davis Lighting Technology Center and the Davis Energy Group advised the architect of the mixed-use housing, San Diego-based Studio E Architects, on energy control systems such as occupancy sensors and dimming controls to manage lighting demand in exterior spaces. Student housing architect MVE Institutional, based in Oakland, included similar features in its portion of the development, and emphasized strategies to provide real-time data to residents on their unit’s energy consumption.

Passive solar design is one of the main energy efficiency strategies at West Village. South-side windows let in low-angle winter sunlight, while strategically placed roof overhangs and sunshades above window frames keep out high-angle summer rays that could potentially overheat units (Figure 12.4). Buildings around the central square were a particular challenge for passive solar design, since long east- and west-facing frontages were unavoidable. Studio E Architects sought to avoid overheating of these buildings from late-afternoon summer sun by placing moveable wooden louvers on rails outside windows. In the same way that people living in Mediterranean countries have covered their windows with shutters for centuries, West Village residents can shade their rooms with these louvers. The architects also oriented large windows and patio doors in each unit to take advantage of cross breezes and to increase natural daylighting. Meanwhile, vertical corrugated metal on south and west sides of the buildings helps create a thermal shield for building walls and ventilate the facades [7].

A related emphasis of West Village is to promote energy-conserving behavior among residents through a variety of strategies. For much of the housing, web and smartphone applications are under development to provide residents with real-time information on energy consumption. These systems are designed to provide residents with access to programmable controls for lighting, appliances, and electrical outlets, although the contractor responsible for installation of these feedback systems did not meet initial performance goals, and how they will perform in practice remains to be seen. However, such informational systems when fully in place should help lead to reduced energy demand by giving residents tools to show how behaviors such as turning off lights and computers or adjusting cooling levels can modify real-time energy consumption.

Research funded by the California Public Utilities Commission grant continues into other strategies that may further reduce energy use at West Village [8]. These strategies include optimizing installed West Village storage battery capacity and use, evaluating other storage options for future use, evaluating the possibility of adding solar thermal arrays to the existing rooftop PV, revised financial models for energy systems on as-yet-unbuilt portions of the project, and developing battery-coupled solar charging stations for plug-in vehicles associated with the neighborhood’s single-family housing. A number of energy systems are likely to be modified in response to actual performance. For example, initial results show that the photovoltaic arrays are producing more than 100 percent of electricity consumed by the apartment buildings. For future buildings it therefore may be possible to reduce the amount of PV in favor of combined PV and solar thermal rooftop systems.

4 On-Site Energy Generation

In addition to the energy efficiency measures discussed above, West Village actively generates its own electricity through extensive use of photovoltaic panels. This generation is intended to offset both electricity use and natural gas use on the site. Originally planners envisioned a large, separate solar array on university-owned land to produce electricity for the new neighborhood. However, detailed studies proved this option unrealistic due to the cost of extensive conduit and inverter infrastructure that would have been required and the lack of available financial incentives to justify this strategy. At this point, the design approach shifted to placing all PV within the footprint of the community, on building rooftops and parking lot canopies. Studio E Architects designed central buildings with a saw-toothed roof configuration that maximizes south-facing surfaces for PVs; south-, east-, and west-facing roofs of the student apartment buildings were also used for solar panels (Figures 12.5 and 12.6). SunPower Corporation, based in San Jose, then installed four megawatts of PV capacity in Phase 1 to power the student apartments and mixed-use buildings. To maximize rooftop PV, project designers refrained from adding solar thermal units for hot water, although this is still a possibility on later phases of the project. As installation of each phase of PVs is completed, annual performance data will be used to inform future phases of project design.

The 2006 West Village energy strategy also planned for construction of a biodigester in which bacteria and enzymes would break down campus dining hall waste, landscape clippings, and manure from campus barns to produce biogases such as methane and hydrogen that could be burned to generate electricity. Both food processing water and animal wastewater can potentially be used as feedstocks as well. The technology is relatively new: although past biodigester systems have used anaerobic decomposition of liquid wastes to produce energy, substantial problems with materials handling, speed of digestion, and economics have prevented commercial application of systems designed to use mixed wet and dry ingredients. In 2006 UC Davis professor Ruihong Zhang in the Biological and Agricultural Engineering Department formed a UC Davis Biogas Energy Project to address these challenges. Assisted by some of the grant funds mentioned above, her group has extensively tested potential feedstocks and has constructed and tested a model Anaerobic Phased Solids Digester on the UC Davis campus that can turn eight tons of waste per day into enough electricity to power 80 households. Zhang’s previous work led to the unveiling in 2012 of the first commercially available, high-solid anaerobic digestion system in the United States, marketed under license by Clean World Partners, a Sacramento-based startup company that is also planning to build the UC Davis system [9]. This system produces energy in about half the time of previous systems, and generates a greater variety of gases that can be burned to produce energy. The same technology is planned for a larger facility on the UC Davis campus, which in the initial energy modeling was seen as necessary to meet ZNE goals (Figure 12.7).

As siting studies and energy analyses have progressed, the campus has realized that it stands to gain greater efficiencies by placing the biodigester facility at a location that may not directly serve West Village, a site near the campus landfill about one mile away. If electricity from this facility does not serve West Village directly, the West Village project may purchase biogas offsets through PG&E in lieu of utilizing output from the biodigester itself. Since the biodigester was seen as producing about one quarter of the electricity used by Phase One of West Village, to achieve ZNE status this amount will need to be made up through the purchase of such offsets, additional PVs, and/or increased efficiencies and incentives for residents to reduce demand. However, by helping catalyze development of biodigester technology, West Village has performed a major service for more sustainable neighborhood-scale energy systems in the future.

Alternative energy features in the single-family West Village housing presented a slightly different challenge than for the apartment buildings. Architects worked to optimize the roof square footage of these smaller structures for PVs. Rooftop capacity on the free-standing alley-loaded garage structures will be kept open, with the aim of being able to accommodate additional rooftop solar if residents wanted extra capacity for electric vehicles.

Indeed, a key benefit of West Village overall will be ongoing evaluation of energy efficiency and renewable energy components to learn from the community’s experience. Since the initial units only opened in late 2011, little data is available as of this writing. It is to be expected that actual performance will be somewhat different than modeled predictions, and that refinements may be needed to achieve ZNE status, such as the addition of more photovoltaic modules, the improvement of informational strategies to change behavior, or other incentive programs for residents to reduce energy consumption. Whatever the case, in the years ahead West Village is certain to become a laboratory for energy systems testing, helping to inform other projects in the future that aim for ZNE status.

5 Other Sustainability Elements

Although it is likely to get the most attention for its ZNE strategy, West Village also seeks to meet sustainability goals in many areas besides energy use. Transportation, stormwater design, climate appropriate landscape design, and affordability measures (in terms of the for-sale faculty and staff housing) are other main areas of sustainable practice.

One of the main motivations for West Village from the start was to encourage as many students, faculty, and staff as possible to live within walking or bicycling distance of campus. This project characteristic should very substantially contribute to the positive environmental effects of the community, since most occupants will not be using fossil-fuel-powered vehicles for their daily commutes. West Village is located approximately 1.5 miles from UC Davis’ central quad, and is even closer to a number of other facilities including the rapidly expanding veterinary medicine complex (Figure 12.8). A below-grade freeway separates the neighborhood from the central campus; however, a pre-existing bicycle and pedestrian bridge provides a convenient connection across this obstacle. City and campus bike route systems then offer primarily off-street paths to reach many destinations throughout town. West Village provides ample bike parking near all units as well as on and off street bike paths through the neighborhood. It also provides a bus transit stop within a five-minute walking distance of all residences, with frequent service to central campus. The transportation system is not part of the ZNE calculations, although energy use for transportation should be much lower than for conventional neighborhoods elsewhere in Davis.

Many West Village residents do own cars, but must park these in peripheral parking lots that discourage daily use. To save space some of the parking is in the form of tandem spaces (one vehicle immediately behind another), a feature that also discourages frequent usage. These peripheral parking lots are ideal for photovoltaic canopies that also provide shade for the parking lots and mitigate some of the heat island effect of large paved surfaces. If these parking spaces were more closely located to each apartment building, the shade cast by buildings would reduce the effectiveness of these lots for solar energy. In large part due to neighbor preferences, campus planners omitted any road connection to Russell Boulevard, the main arterial street to the north of West Village connecting to the city’s downtown. To drive into town residents must follow a more circuitous route to the south, further discouraging motor vehicle use. The Davis downtown is about a 2-mile bicycle ride from West Village. As of fall 2012, neighborhood residents will not be allowed to purchase campus monthly parking permits unless they have specific access needs, so regular commuting to the central campus by car is eliminated. ZipCar currently operates car-sharing sites on campus, and in the future the university plans to open a car-sharing pod at West Village, and to explore the possibility of using all-electric vehicles for this purpose.

Water is another area of sustainability emphasis at West Village. Apartment fixtures go considerably beyond code in terms of water conservation; toilets use only 1.28 gallons per flush, and shower faucets dispense only 1.5 gallons per minute, 40 percent below code. The project’s design attempts to keep all stormwater onsite, in part through swales, landscaping, and green street features that encourage rain to infiltrate into the ground where it falls, and in part by channeling overflow to a series of seasonal ponds in the greenway to the north of the neighborhood.

West Village landscape design emphasizes native trees such as California live oaks, valley oaks, and California sycamores; native shrubs such as toyon, manzanita, and ceanothus; native grasses such as Muhlenbergia rigens and California fescue; and other native plants such as rushes and sedges. All of these species are drought-tolerant, and much irrigation utilizes water-saving drip systems or micro-sprayers. Turf areas are concentrated in locations with active outdoor uses. Landscapes such as tree strips between roadside curbs and sidewalks are planted with low water-using plants.

From the beginning campus planners intended to promote economic and social sustainability goals by providing faculty and staff housing for sale at below-market prices. In order to keep these homes affordable for future generations, the agreement between each homeowner and the university includes provisions to cap the rate of annual appreciation for the for-sale housing, a strategy that the university previously employed on its much smaller Aggie Village development built in the 1990s near the Davis downtown. West Village homebuyers will only be able to sell at fixed rates of appreciation, and the university has right of first refusal on all sales. This mechanism provides a relatively small and predictable increase in home value to the owner and avoids large positive or negative swings that may occur in the open market. The 2008 housing crash has lowered real estate prices in Davis by about 20 percent, and prices in nearby cities such as Sacramento even more, greatly increasing the difficulty of providing below-market housing. However, housing in Davis is still the most expensive in the region, and as the market recovers the need for affordable housing for campus employees is likely to grow once again. The build-out of for-sale housing at West Village is anticipated to be slower than originally expected due to market conditions, but the underlying model is not likely to change.

Other sustainability features inside the buildings include recycled quartz countertops and 50 percent recycled flooring in the student apartments, ceiling fans in all rooms, and low volatile organic compounds (VOC) finishes throughout. Much of the lighting in units was hard-wired in place, a strategy that increases the likelihood that residents will use these highly efficient fixtures rather than bringing in their own halogen or incandescent lamps. Somewhat detracting from the eco-image but certainly appreciated by students on hot days, a large swimming pool is located immediately behind the welcome center; unfortunately in the effort to maximize PV rooftop space solar thermal for the pool was not included. To ensure that units would be attractive to potential residents, the developer has given a decidedly up-market character to West Village. Every bedroom of student housing in the initial phase, for example, has its own bathroom and a walk-in closet. The recreation center and pool add to the amenities. Not surprisingly given this level of appointment, rents are at the upper end of the Davis market. However, the sheer number of new apartments offered at West Village should help moderate rental prices in the local Davis market and relieve very low vacancy rates that lead to higher rental pricing.

Perhaps the most important contribution of West Village to sustainable community planning is the demonstration that ZNE is being achieved with no greater cost to the West Village resident. The project shows that the same dollars used to pay a resident’s typical energy bill can be redirected to pay for energy efficiency and green power when planned in a holistic way, resulting in a large-scale ZNE community. Overall, in terms of financially viable ZNE performance, transportation demand reduction, water use, and landscape treatment, West Village appears at the cutting edge of global ecodistrict development.

6 Conclusions

As the first large-scale ZNE neighborhood in the United States, West Village provides a powerful model of how society might move towards a ZNE status for primarily residential mixed-use communities. The project is somewhat unique in that it benefited from a powerful institutional sponsor, the University of California, Davis, which was willing to experiment, had access to a wide range of technical expertise, owned the land, and did not have to subject development plans to local land-use planning approval processes. It also benefited from a political climate in which interest in lowering greenhouse gas emissions was rising rapidly in the state, and from a favorable climate and geographic context for keeping energy use to moderate levels. Those factors certainly helped enormously in attaining ZNE goals. However, West Village is largely a private-sector financed and managed project, and there is no reason why many of West Village’s features could not also be incorporated into private sector development projects or neighborhoods in other parts of the world. The passive solar design features and the ‘reduce, then produce’ approach in particular involved relatively simple strategies that should be replicable in most places.

Although detailed studies of actual energy use, renewable power generation, and resident behavior must await the availability of data, a few energy-related lessons can already be gleaned from West Village. One basic lesson is the importance of combining three main strategies – passive solar design, energy efficiency measures, and active renewable energy – within the effort to achieve ZNE status. None of these strategies alone could have met West Village’s energy goals. Without halving electric usage through efficiency strategies, for example, PV would never have come close to meeting the neighborhood’s needs on the available rooftop and parking lot space. Another main lesson is the importance of designing ZNE strategies into a project from the start. For example, because the first West Village rooftops were not originally envisioned to carry solar panels, they contained vents and protrusions that made later PV installation more difficult. Once the ZNE model was embraced those elements were consolidated on the north slopes of rooftops to avoid conflicts with energy systems.

However, West Village’s development overall has illustrated a fortunate synergy between a willing and creative institutional sponsor, many public and private sector partners with technical and development expertise, and a supportive political climate. With these elements in place, planners are optimistic that the neighborhood will in fact meet its ZNE goal at no greater cost to the resident than a “business-as-usual” scenario. By embracing a community-wide approach that stretches from street layout to light fixtures, it also seems likely that similar projects elsewhere could reduce energy demand to the point where energy needs can be supplied by on-site renewable power.

References

1. California Public Utilities Commission (CPUC). Zero net energy action plan. Sacramento. Available online at <http://www.cpuc.ca.gov/NR/rdonlyres/6C2310FE-AFE0-48E4-AF03-530A99D28FCE/0/ZNEActionPlanFINAL83110.pdf>; 2010 [accessed 08.05.12].

2. Royal Institute of British Architects. (RIBA). RIBA Journal sustainability award BedZED, Web resource available at <http://www.architectsjournal.co.uk>; 2003.

3. Dakin B, Hoeschele M, Petouhoff M, Zail N. Zero energy communities: UC davis’ west village community. Working paper presented at the ACEEE summer study 2010.

4. Corbett J, Corbett M. Designing sustainable communities: learning from village homes Washington, D.C: Island Press; 1997.

5. City of Davis. Davis sustainability, Web resource at <http://cityofdavis.org/cdd/sustainability/>; 2012 [accessed 08.05.12].

6. Finkelor B, et al. West village: a process & business model for achieving zero-net energy at the community-scale Davis: UC Davis Energy Efficiency Center; 2010.

7. Vinnitskaya I. U.C. davis west village/studio e architects. Archdaily. march 17, 2012. Web resource at <http://www.archdaily.com/215764/uc-davis-west-village-studio-e-architects/>; 2012 [accessed 03.05.12].

8. Braun G, Hayakawa M.G. 2011 Annual report, west village energy initiative: CSI RD&D project. Davis: U.C. Davis; 2012.

9. U.C. Davis News and Information Service. Researcher’s waste-to-energy technology moves from lab to marketplace. Web resource available at <http://www.news.ucdavis.edu/search/news_detail.lasso?id=10202>; 2012 [accessed 04.05.12].