1. THE BUILDING AS POWER PLANT

Environmentally sustainable and even zero-carbon buildings are no longer utopian fantasies. They can be built and operated economically. This ambitious goal cannot be achieved through isolated measures, but only through carefully coordinated, sys-tematic planning. From an early planning phase, the architects and energy experts form interdisciplinary teams that develop all the components of the system. This process results in the freedom to adjust specific components according to prefer-ences: the choice of a particularly economical variation in one area permits addi-tional luxury in another. Does architecture lose its guiding role in the planning proc-ess for highly competitive projects? The examples from this group demonstrate the contrary.

Rock Crystal – New Monte Rosa Hut, Zermatt – Swiss Alpine Club (SAC), Monte Rosa Section – Studio Monte Rosa, ETH Zurich, and Bearth & Deplazes Architects Ltd. – Completed in 2009

The Swiss Federal Institute of Technology (ETH) Zurich, together with the Swiss Alpine Club, launched the pioneering project for the new Monte Rosa Hut at 9,458 ft. above sea level. The result was an atmospheric building in the form of a shimmering rock crystal. The building structure was based on modular construction using a wooden frame and digitally designed components, whose weight was optimized to keep the number of heli-copter flights to a minimum. Solar collectors measuring 645 sq ft and photovoltaic cells measuring 1,313 sq ft in combination with a battery system make the building 90 percent energy independent. An intelligent-building control system helps improve efficiency


Experimental Laboratory – B 35 Residential Building, Zurich – Dr. Hansjürg Leibundgut – agps architecture, Zurich and Los Angeles2009–10

The private owner conceived this four-family building as an experimental laboratory for technical innovations in accordance with his theoretical concept, which aims for CO2-free operation. The outer walls are a double shell of insulating Misapor concrete. The core element is a geothermal probe down to a depth of 820 feet. Excess solar radiation on the building is stored in the ground. When heat is needed, a thermal pump supplies it to the heating system. The systems are designed for small differences in temperature, which means that little electricity is expended. Additional heat is obtained from a hybrid collector on the roof and from outgoing air. The sole external source of energy is electricity from renewable energy sources.


Energy Pioneer – Eawag Forum Chriesbach, Dübendorf – Der Energiepionier / Energy Pioneer – Eawag Forum Chriesbach, Dübendorf – Eawag, represented by Empa Building Technologies – Bob Gysin + Partner BGP Architects – Competition 2003, Completed in 2006


Energy Pioneer – Eawag Forum Chriesbach, Dübendorf – Der Energiepionier / Energy Pioneer – Eawag Forum Chriesbach, Dübendorf – Eawag, represented by Empa Building Technologies – Bob Gysin + Partner BGP Architects – Competition 2003, Completed in 2006

Eawag, the Swiss Federal Institute of Aquatic Science and Technology , established a milestone with its pioneering new building. The goal of building a zero-energy house called for a particularly intense planning process. Blue slats of glass on the outer facade control the sunshine entering the building. Behind them lies the solid shell of the building, consisting of glass and highly insulated wooden elements. The air is heated with the help of a ground heat exchanger and waste heat from electronic equipment. The generous atrium is an architectonic element that supports the ventilation concept. Clay-stud parti-tioning walls separate the offices and create a desirable indoor climate.

2. RETROFITTING THE STOCK

The existing stock of buildings in our cities represents by far the greatest potential for savingenergy. The buildings that predate the “oil crisis” of 1973 use much more en-ergy than necessary, and they comprise between 80 and 90 percent of the present building stock. Even modest measures such as insulating basements and attics, re-placing windows, and carefully conceived interior insulation can result in consider-able savings without altering the expression of a building. If, however, the potential for savings is to be truly realized when renovating the building, a systemic approach is required.

BUILDING ON

Residential Building, Seebahnstrasse 143, Zurich EcoRenova Ltd – Viridén + Partner Ltd. – Direct Commission, Completed in 2006

Built shortly before 1900, the building is a row house typical for this district. The recon-struction project improved both the quality of life and the energy efficiency. The ornate brick facade was not changed. By contrast, the courtyard facade was demolished and moved 5 feet into the courtyard. A new layer of space was added to house bright eat-in kitchens with balconies and a new elevator. Adding a floor was crucial to the economic viability of the intervention. Eighty percent of the shell was reinsulated. Windows with three panes of insulating glass, comfort ventilation, and solar panels on the roof improved the quality of life on a noisy street.

FRESH- CELL THERAPY

Heumatt High-Rise, Urs Primas City of Zurich – Urs Primas, and Proplaning Architects and Developers – Competition, 2002, Completed in 2005

This residential complex, built in 1973, consists of a high-rise and two six-story residential buildings. All three houses were given a well-insulated, rear-ventilated facade cladding of aluminum panels. The two low-rises remained occupied during the renovation and were only slightly renovated inside. The interventions were more significant in the high-rise: small apartments were combined to form a larger one. The result was maisonette apartments with two-story loggias and flats with special features such as views in two directions, and a second entrance to the apartment. After renovation, the high-rise meets the Minergie (low-energy) standard for conversions. The ducts for the controlled ventilation of the units were integrated into the new facade.

CULTURAL HYBRID

niversity of the Arts at the Toni Dairy, EM2NToni Dairy, Zurich – Allreal Toni Ltd and Canton of Zurich – EM2N Architects Ltd – Two-stage competition, 2005–6, completion in 2011

The Toni Dairy, a former milk-processing facility built in 1977, is becoming the new head-quarters of the Zurich University of the Arts. This industrial building, with expansive structures and tall supports, allows for flexible use.The raw charm of the industrial site lives on in the new design. The silhouette of the building, including its spiral truck driveways, was preserved and made even more dramatic by the residential high-rise. Five large atriums articulate the enormous mass of the building, providing natural light and joining to form a circulation space with a set of cascading stairs. Roughly a quarter of the rooms are occupied by apartments, cultural facilities, and cafés and restaurants.

3. COMMUNITY PROJECTS

The 2,000-Watt Society is not merely a technological project to save energy. The vision also aims to achieve a shift in values by establishing new concepts of quality of life and learning to live together with greater solidarity. It is about equal and fair access to limited resources. Individuals can only partially contribute to those kinds of changes; small or larger communities, however, can successfully embark on new paths. Various cooperative housing associations in Zurich want to create spaces for a forward-looking lifestyle; to that end, they are betting on the possibilities of community. With an attractive mix of residents, small and larger offices, and stores and restaurants, these new communities want to radiate their charisma into the city.

AN URBAN MIX

Kalkbreite, Müller Sigrist – Mixed-Use Development Kalkbreite, Zurich – Kalkbreite Building Cooperative – Müller Sigrist Architects – Open Competition, 2009 – Project, Completion in 2013

The newly-founded Kalkbreite Cooperative wants to connect new forms of communal living and working with high ecological standards in the spirit of the 2,000-Watt Society. The centrally located building complex offers living space for 250 residents and an equal number of workspaces. Shops and restaurants add value to the neighborhood. Common roof terraces, high-quality common areas and exterior spaces, and a “rue intérieure” cascading through the building allow this project to offer diverse spaces. Moreover, the project conforms to all the important rules for an energy-efficient building: com-pact volume, seamless insulation perimeter, sealed building shell, passive use of solar radiation, and the use of renewable energy.


More Than Living / mehr als wohnen Building Cooperative – FUTURAFROSCH and DUPLEX Architects, Müller Sigrist Architects, Miroslav Šik, pool Architects – International Competition, 2009 – Project, Completion 2013–15

More Than Living is the name and ambition of a cooperative housing association founded in 2007. It seeks to facilitate new forms of living and working in the spirit of the 2,000- Watt Society. The architectural competition sought innovative contributions to a form of housing development that would bring together work, housing, and leisure. Four architectural offices were selected to initiate a dialogue and turn their competition entries into a joint project.The integration of the site into the neighborhood is achieved by networking the exterior spaces and presenting urban density as a source of identity. The layout of the floor plans transfers the theme of paths and public squares into individual residential floors. One highly promising concept is the idea of suites that combine private and communal living.


Sophisticated Inner Life – Eichmatt School, Bünzli-Courvoisier – Eichmatt Schoolhouse, Hünenberg / Cham – Communes of Cham and Hünenberg – Bünzli & Courvoisier Architects with b + p baurealisation Ltd. – Competition, 2006, completed in 2009

The Eichmatt Schoolhouse's large volume dominates a new residential district between Cham and Hünenberg. Large windows and a highly articulated larch facade characterize the outward appearance. The classrooms are brought together into clusters. This layout supports contemporary models for learning. The auditorium, the gymnasium, and the exterior spaces are available to the public.The compact design is crucial for the energy efficiency of the building. The high percent-age of window area in the classrooms optimizes natural light. Fourteen geothermal probes down to a depth of 490 feet regulate the internal excess heat and the heat requirements on cold days with the help of the soil. The solar electricity produced on the roof nearly meets the school’s total energy use.

4. BACK TO THE MATERIALS

Inherently sustainable, long-lived, regionally and historically grounded construction methods such as rammed earth and solid brick not only have a unique power of architectural expression, but also achieve astonishingly good energy values. The unusually large storage capacity of the building itself has a positive effect on the use of energy. Building with wood also has great potential, especially with regard to gray energy.


Archaically Modern – Rauch Clay House, Schlins (Vorarlberg) – Rauch Clay House, Schlins – Lehm Ton Erde Baukunst, Rauch Family –Consortium Roger Boltshauser, Martin Rauch – Direct Commission, Completed in 2008

Rarely is the idea of sustainability expressed as artistically and convincingly as in this private home. Nearly all of the building material from the house was derived from clay, more than half of which was taken from the material excavated on site. Unfired clay requires little gray energy, offers a great deal of thermal storage, and ensures a comfortable climate.Layers of rammed earth and inlaid tiles characterize its prismatic outward appearance. The stamped-out openings make the thickness of the walls apparent; they are composed of 18 inches of rammed earth, an insulation layer of reeds, into which heat exchangers are inserted. The interior of the house is characterized by exciting sequences of rooms and the silky gleam of ivory plastered surfaces.


Monolithic – Apartment Building at Neptunstrasse 25, Zurich – Residential Building on Neptunstrasse, Zurich – A. Hess, A. Maier Maier Hess Architects – Completed in 2008

This apartment house in Zurich shows the possibilities for insulating concrete. The material used here is Misapor, a concrete mixed with insulating granules of crushed foam glass. The sharp-edged building volume has large windows to the south and east. The alternation of bands of parapets and horizontal windows with angled jambs gives the facade a very sculptural, relief-like look.The apartments feature generous proportions and a sparse use of materials. They have controlled ventilation with heat recovery. The floor heating is fed via a warm air pump that uses the underground parking garage as a ground heat exchanger. The large storage capacity of the building helps balance out fluctuations in temperature.


Invisible Wood – Housing Complex on Badenerstrasse, Zurich – Residential Complex on Badenerstrasse, Zurich – Zurlinden Building Cooperative – pool Architects – Competition, 2006, completed in 2010

These six interlocking, six-story residential buildings are largely wood structures. The subterranean and ground floors are concrete, as are the central service shafts; the load-bearing structure of the residential floors employs the Top Wall wood construction sys-tem. The walls consist of vertically joined wooden planks insulated on both sides. The new buildings satisfy the requirements of the 2,000-Watt Society both for construction and operation. They respond to their urban, but also noisy surroundings with an architectural typology suited to the inner-city location. The ground floor houses a supermarket, and its waste heat is used to heat the apartments. The combination of a photovoltaic system with a groundwater thermal pump ensures a sustainable energy supply.


Gravity in Stone – Kolumba, The Art Museum of the Archdiocese of Cologne – Archdiocese of Cologne – Atelier Peter Zumthor & Partner Competition, 1997 – Completed in 2007

The new museum rises from the ruins of the Gothic Church of St. Kolumba, which was destroyed in the war. The ground floor spans across the excavation field as an open hall; steel supports bear the exhibition floors above it.The architecture of the building lives from the sequences of spaces and the reduction to a few carefully chosen materials: the walls are made of hand-shaped bricks, partly covered with clay; the floors are Jura limestone, terrazzo, and mortar. This construction leaves no room for visible building services installations or conventional insulation. Rather, the enormous storage capacity of the walls and ceilings ensures a balanced climate. It is activated with water, which is cooled or warmed via a thermal pump with ground heat ex-changers and groundwater springs.

5. COMPACT AND SMART

Compactness of buildings is not an absolute requirement, but one of many components in an energy-efficient design. Large office buildings and hospitals offer the best conditions for compact volumes. In their case, the crucial challenges consist not in the heating, but rather the cooling of the building and good natural light in the interior. Glass facades and light wells are designed to maximize the daylight reaching the interior. In order to cool and heat efficiently—that is to say, with minimal temperature differences—the storage mass of the concrete ceiling is activated. This precludes drop ceilings and requires special solutions for running cables and pipes in the building.

Landmark

Triemli Hospital, Zurich – New Ward, Triemli Municipal Hospital, Zurich – City of Zurich – Aeschlimann Prêtre Hasler Architects – Selective Study Commission, 2005 – Project, Completion in 2015

The new ward building of the Triemli Municipal Hospital is a beacon project on the road to the 2,000-Watt Society and a key part of the renovation of the hospital, which opened in 1970. A master plan ensures that the hospital will always be able to perform its function by leaving room for future changes in the hospital’s complex operations. The new compact building in the center of the hospital grounds responds to this requirement with a flexible structure of access and circulation, and accessible building services installations. The glass facade and transparent interior allow natural light into the building and provide a friendly atmosphere. The clay ceilings contribute to a healthy climate inside by maintaining balanced temperature and humidity.

Efficient Headquarters

Credit Suisse Uetlihof, Zurich – Credit Suisse Headquarters, Uetlihof 2, Zurich – Credit Suisse Real Estate – Stücheli Architects – Direct Commission – Under Construction, Completion in 2011

This impressive new building with more than 2,000 workspaces meets the requirements for the Minergie-P-Eco label and the 2,000-Watt Society. The nine-story building is conceived to be extremely compact. The open-plan landscape of office space is subdivided into functional spaces such as meeting areas and team and technical zones. Three light wells provide natural light throughout the building.Internal heat sources and the electricity consumption of the workspaces present a major challenge. The concentration of ventilation, cooling, and acoustics in installation islands makes it possible to get by without drop ceilings and to actively use the thermal storage capacity of the building for cooling.

Heavy Butterfly

Trotte Municipal Retirement Home, Zurich – Trotte Municipal Retirement Home, Zurich – City of Zurich – Enzmann + Fischer Architects – Competition, 2006, Completion in 2014

The new retirement home will be open to its surroundings and leave enough open space for a park. The dexterous modeling of the volume breaks down the large scale, resulting in a ground plan like a butterfly. Heat recovery from sewage water provides most of the heat required; a wood pellet heater covers peak periods. The large windows of insulating glass pro-vide good light in the units and bring in solar heat. Most of the concrete employed is recycled.The new retirement home offers its residents assisted-living services according to individual needs, with a two-story common area. The park and cafeteria on the ground floor are open to neighborhood residents.

6. THE SCALE OF THE CITY

The city of the 2,000-Watt Society has to be a city of short paths. There must be at-tractive paths and spaces for walking and cycling and places to linger; a well-coordinated public transportation network will reduce the need for individual motorized forms of transportation. Automobiles will increasingly be used in car-sharing systems or run on electricity.A city of short paths is densely built—like many of the older inner-city neighborhoods so popular today, but which were built before the automobile was introduced. That allows for an attractive selection of stores and leisure-time activities and increases the compactness of the built mass. Only when there is sufficient public and private green space can heat islands be avoided in summer so residents will occasionally do without their Sunday excursions.

Urban Density

Freilager Albisrieden, Zurich – Freilager Albisrieden, Zurich – Zürcher Freilager Ltd. – Master plan: Meili, Peter Architects, Zurich, Vogt Landscape Architects, Zurich – Architecture: Meili, Peter Architects, Rolf Mühlethaler Architects, Zeno Vogel – Study commissions 2010 – Completion in 2015

Zürcher Freilager AG intends to oversee the creation of a sustainable neighborhood with urban density. This encompasses workplaces and neighborhood supply facilities, as well as apartments for families, students and older people. Historical warehouses will be retained and converted for mixed use; high-rise buildings add character along the busy street. Spacious open areas connect the Freilager neighborhood to the surrounding residential areas. At the same time, the neighborhood's ambitious energy, climate and transportation concept makes a key contribution to the implementation of the 2,000-Watt Society. The projects were developed via competitions and study commissions. The proprietor is planning for the long term and considers herself responsible for the neighborhood throughout the entire life cycle of the building complex.

Passive House District

Eurogate Vienna – Eurogate District, first developmental phase, Aspanggründe, Vienna – Magistrate of the City of Vienna – Developers' Competition, 2007 – Project, Completion 2011–16

On an abandoned rail yard of roughly fifty acres, 1,700 affordable apartments, the majority of which are publicly subsidized, are scheduled to be built by 2016. A dense urban architectural typology will be arranged around a public park. The new district has excellent access to public transportation, and its mix of housing, shops, and offices is meant to en-sure an urban lifestyle.In 2007, there were competitions for bids from developers for the seven construction sites of the first phase of development. Lowest energy consumption and passive-house construction as well as typological innovation were imperative for all the buildings and represented the central architectural challenges.

Urban Density

Carlsberg City, Copenhagen – Carlsberg City, Copenhagen – Carlsberg A/S – Entasis – Masterplan, International Open Competition, 2007 – Completion 2012–2024

The eighty-acre site of Carlsberg Brewery on the edge of central Copenhagen had long been famous for its imaginative buildings. The relocation of production made a new use of the site possible, and an international competition in 2007 paved the way for future development.The winning proposal wants to simultaneously maintain the historical building fabric and enable urban density and activity. The perimeter-block construction typical of Copenhagen is continued in a new district, supplemented by slender high-rises. A wide spectrum of measures contributes to the sustainable character of the neighbor-hood. A new suburban railway station and a network of streets designed to accommodate pedestrians and bicycles connect Carlsberg City to Copenhagen’s outstanding bike paths and public transportation system. Regenerative energy is enforced by stipulations in the district's building code. Ideas for a sustainable approach to water and recycling of trash and construction materials supplement the overall planning.