In this video, lighting designer and author Randall Whitehead IALD discusses energy-efficient lighting design. With several examples of LED and fluorescent lighting, Randall dispels the myth that a compromise in design must be made when choosing these efficient, long life alternatives to incandescent lighting.
Click here for the video.
With so much buzz surrounding the modern green movement – grant money, tax credits, and an ever increasing market demand – there is an important question of the associated role of water and where it stands. Energy, for the most part has been a topic that has elicited an enormous political response, especially, at the federal and state level, with generous incentives and subsidies to homeowners encouraging investment in their own residential energy systems. These energy savings in green buildings are of course very beneficial and are predicted to save approximately 45 million metric tons of carbon output within the next four years. This is the equivalent of taking 8 million cars of the road! But, what is also very astounding is the amount of energy that can be saved by de-centralizing water systems, capturing and using on-site water resources for outdoor purposes, as well as for toilet flushing and washing machines. This practice can equate to a 60-80% percent decrease in annual water use which also entails huge energy savings. California, the second highest energy using state in the U.S., shockingly uses approximately 30% its energy to move and treat water. Most people don’t realize that the water coming out of their faucet originated hundreds of miles away. If homes can be furnished with independent energy systems using governmental incentives than why can’t independent water systems be under the same umbrella? … pun intended. Using alternative energy to supply power to small residential pumping systems supplying water for 60-80% of a building’s total water needs, equates to an astounding energy savings of approximately 21-28 million metric tons of carbon output per year! In four years, this adds up to 84-112 million metric tons of carbon or the equivalent of 14.8-19.6 million automobiles off of the roads. The profound implications of water and its relation to energy or “watergy” has unfortunately been held under the radar for far too long.
These numbers, though substantial, are still only taking into account residential water use and corresponding energy savings. Utilizing rainwater for cooling and toilet flushing in commercial office and retail buildings, public institutions and hospitals could increase energy savings by much more. When the continuing threat and impact of global climate change has been simplified to an over abundance of carbon in earth’s atmosphere an important question to ask is this: What is the carbon footprint of a glass of pure rainwater caught from the clouds supplied via gravity, versus, the carbon footprint of a desalinated glass of water filtered from a high saline source and pumped miles to your faucet?
Though the topic of this discussion has primarily been about energy, the other, more apparent issue is water scarcity. By being aware of water use and supply in any development or future development, and taking certain steps to limit unnecessary water waste as well as harnessing on-site water resources, we can tackle the looming issue of a water crisis. There are numerous projects that have incorporated water saving strategies as well as on-site rainwater or greywater reclamation systems that have been documented to have reduced water usage by 60-70%. The most notable examples of these projects are in Australia, where it is common place to utilize rainwater for interior as well as exterior purposes. It is also important to note that only 10 years ago there was almost no legislation of this practice which now is considered mainstream. Water sustainability can be accomplished in most old and new developments as long as a comprehensive approach is taken. Given our dwindling groundwater supplies, ever increasing population, reduced snowpack and state budget woes, large scale solutions to water shortages cannot be depended on to solve the problem.
“We can obtain real water from a Virtual River of water efficiency, trimming water waste, recycling wastewater, and capturing rainwater in urban areas before it flows into storm drains. There’s more water available from these sources than we’ve ever exported from the Delta.” – Doug Obegi
This quote sums up the potential solutions to water availability and is very profound given all of the political issues that constantly come up regarding water rights and diversion debates. A top down effort and decentralized approach to natural resource conservation and management is of the utmost importance in the focused efforts of the 21st century’s green movement. All energy and water systems are inextricably interconnected in nature, and the same goes for modern society. Water and energy are the two main driving factors for life on earth and should continue to be, as we responsibly carry on humanity through sustainable development for centuries to come.
Bobby Markowitz, founder of Earthcraft Landscape Design, has been designing rainwater harvesting systems and educating professionals for nearly a decade. A licensed Landscape Architect, Accredited Professional by the American Rainwater Catchment System Association, Certified Permaculturist (taught by Founder Bill Mollison), Mr. Markowitz has advanced the viability of water conservation systems into the forefront of landscape architecture. A graduate of Rutgers University, Mr. Markowitz’s work is influenced by his study abroad in Japan and advanced water harvesting workshops in Australia. A frequent guest lecturer and keynote speaker for numerous Landscape Architecture and Rainwater Catchment System Associations, Mr. Markowitz has provided valuable insight into the design of sustainable sites and water conservation systems. In addition to his practice, Bobby Markowitz also teaches “Rainwater Harvesting System: Principles and Design” at Cabrillo College.
In May 2009, five curious new wavy red-roofed bus shelters were constructed around San Francisco. Their unorthodox design and interesting features have garnered recognition in many circles around the world, but very few have heard of the highly innovative and collaborative story behind this great green project.
According to Lundberg Design project manager Ryan Hughes, the biggest misconception about the project was that funding came entirely from the city of San Francisco. Instead, the city served as an enabler and beneficiary. The SFMTA administers a long-term lease of the new bus shelter locations and advertising space, making the city a major beneficiary of the project, in terms of revenue and public infrastructure, but not the project’s financial investor.
Typically, bus shelters are financially viable because they are paired with large advertising boards, which outdoor advertising agencies negotiate rights for. In late 2006, SFMTA issued an RFP for a 20-year lease of the bus shelters as the current contract was coming to a close. The scope of the RFP included the design and construction of 1100-1500 new bus shelters, which called for integrated solar power or green features, and universal design/accessibility requirements. In return the companies had exclusive rights to sell advertising with over fifty percent of the revenues to go back to the city. The RFP bidders (and ultimately, the contractor for these innovative new bus shelters) were all major outdoor advertising companies such as CBS/JC Decaux, ClearChannel Outdoor and CemUSA.
The three outdoor advertising companies each submitted between 10-15 new shelter designs, for a total of about 35 designs to be reviewed by various city agencies. Clear Channel Outdoor chose to take a local route, hiring three San Francisco-based architecture firms to come up with designs. The boldest entry came from Olle Lundberg of Lundberg Design, who proposed a glowing wavy translucent roof as a signature feature. The shape was chosen to evoke both the multiple hills that make up San Francisco’s dramatic landscape, as well as the seismic waves triggered by occasional earthquakes. While unconventional, the strength of the strong design statement was undisputed and Clear Channel Outdoor was eventually rewarded the contract, exclusively using the Lundberg Design bus shelter.
Striking as the roof was, it served as more than just a dramatic design gesture. There was a strong ecological justification behind the translucent red panels and the design and material selection process is a unique case study for innovation and material development. Lundberg Design searched high and low for a material appropriate to realize the curvy wave form. After considering glass and metal, they worked closely with 3form, a company known for their composite plastic materials, to adapt their Koda XT line, which includes 40% pre-consumer recycled plastic. Koda is a highly durable polycarbonate material that can withstand the toughest exterior conditions: wind loads, moisture, thermal expansion in heat and contraction in cold. Working together, Lundberg Design and 3form modified the shape to take advantage of the strengths of the Koda material, adding additional thermo-formed curves to the originally flat end portion of the roof, to allow the ½” thick polycarbonate to span over four feet between the roof supports without sagging.
To raise the bar on ecological design performance, the designers wanted the roof to be a productive element itself. The original design intention was for the roof to filter light but also harness light to create electricity. Looking for the right photovoltaic product to integrate with 3form’s Koda line required a lot of collaboration. Konarka Technology is a plastics company that makes a polymer based photovoltaic film, Power Plastic, which differs from typical photovoltaic cells that require silicon. Konarka’s film consists of an organic dye printed on a clear plastic substrate to convert sunlight to electricity. The inspirational design concept led to a pioneering project to encapsulate the Power Plastic modules into a colorful three dimensional and resilient structure. The challenge for Lundberg Design, 3form and Konarka was to develop a manufacturing process and assembly detail that would essentially assimilate the Konarka Power Plastic film to the curvy Koda XT roof structure without damaging the photovoltaics, and while maintaining a clean layout with even spacing of the photovoltaic film pieces. After several rounds of testing lamination techniques and the development of custom molds, 3form devised the optimal assembly and process conditions to allow for successful lamination of the Konarka Power Plastic to the bold colors of the curvy Koda XT panels.
But what were the photovoltaics for? The bus shelter roof was designed to produce enough electricity to do several things: 1) power an LED message board that gives NextBus updates, 2) power “Push-to-Talk” features which reads the NextBus information aloud for hearing impaired travelers, 3) operate a wi-fi router and 4)power lights for advertising panels at night. During the day, the roof generates more electricity than the NextBus sign,” Push-to-Talk” and wi-fi router requires and the shelters actually add energy to the grid. Working with PG&E, the design team managed to connect the shelters directly to the grid and outfit a meter that runs in reverse. At night, lighting the advertisements within the shelter consumes grid power, but the overall electricity usage is close to the amount generated by the panels.
In the seven months since five prototype bus shelters were installed, representatives from Konarka have tested the performance of the integrated solar panel, and found it to be performing slightly above expectation. From the general assessment by Lundberg Design’s team, overall the shelters break even in terms of energy usage, generating enough power during to day to power all functions and sell energy back to the grid, and by night, spending about the same amount of energy that they put into the grid.
The San Francisco Bus Shelters are a great new model for green architecture, not just in terms of design, but in terms of technology and innovation, collaborative partnerships and a financial viability. For many of us who believe in the value and practice of green principles in our design work, realizing green projects may require changes in our practice models. The standard architect-client relationship may not be enough, and creating innovative, high impact design projects may require engagement and collaboration with a broader spectrum of stakeholders. The success of the SFMTA Bus Shelters is a strong example not just of the design potential but of the partnership possibilities.
Elaine Uang works at Feldman Architecture.
Sustainable cities require sustainable communities as well as care for the environment. Brazilian architect, Jorge Mario Jauregui has been working in Rio de Janiero for the last fifteen years to use his skills as an architect to bring infrastructure and community facilities to the informal communities throughout the city known as favelas. Favelas, which house about 20% of the city’s population, have been growing in pockets of unclaimed land throughout the city for the past 100 years. However, since unplanned and originally unsanctioned by the government, these communities lack infrastructure and public social spaces.
Jorge has coined the phrase “favela-barrio” to describe his approach to urban design in the favelas. Literally translated as ‘slum-neighborhood’, it expresses the idea that these informal developments, or shanty towns, are here to stay and are thriving communities; and with some infrastructure and public space can be transformed into neighborhoods. Jorge envisions the potential of the existing network of paths and roads. His architectural interventions involve providing basic services such as water, electricity, and footpaths, and often incorporate the creation of facilities that promote interaction in the form of recreational and community centers. The structures proposed and built by Jorge’s firm are bold and iconic, creating a strong sense of place.
In a project currently underway, Jorge is creating public space in the Manguinhos favela on existing train tracks that bound the community on one side. These train tracks will be elevated and the space below will become a linear park, defined by the conjugation of spaces, activites, buildings and vegetation. Facilities in the park will include sport, cultural, and income generating facilities, with a focus on providing children and teenagers with alternative attractions that will integrate them into the community. The space will also incorporate a new public transportation hub.
This new metropolitan park will be an articulator, attracting favela residents as well as a larger public from the surrounding communities. As an integrated public space it eliminates the existing barrier and transforms the space from divider to connector. By directly intervening at the physical boundary of the favela, Jorge is directly confronting the deeper socio-economic divide that has plagued the city for decades.
Read more on Jorge’s website at: http://www.jauregui.arq.br/
Bridgett Shank works at Feldman Architecture. She had the opportunity to work with Jorge Jauregui in Rio De Janiero.
Those people who want energy efficiency but are turned off by the compact fluorescent lamps (CFLs) that they are finding at their local home stores should take a look at cold cathode fluorescent lamps (CCFLs). They come in the shapes that we all use, such as household bulbs, flame tip and globe; and are available in numerous color temperatures. My personal favorite color is the 2250K.
The household bulb version of this lamp is the Micro-Brite by Litetronics (www.litetronics.com) is the MB-801DL-2250K, which is a beautiful warm incandescent yellow. These dim with a standard incandescent dimmer and have close to full range dimming capabilities. They last from 18,000 to 25,000 hours and retail for around $12.00; saving from $33.00 to $73.00 in energy costs over the life of the bulb. They can be purchased on-line at such websites as www.1000bulbs.com.
A note about the accompanying images- The CCFLs pictured here have clear glass envelopes to show what is going on inside but are available with white glass envelopes as well, so that they look like their incandescent counterparts.
CCFLs come in the most popular sizes
- This CCFL globe light shows the warm color
- This sconce uses an 8-watt CCFL
- This six foot pendant uses (3) 8-watt CCFLs
To get more tips on lighting or to learn more about our services go to www.randallwhitehead.com
Randall Whitehead IALD is an internationally known architectural lighting designer, based in San Francisco. He is not only a prolific author, but an enlightening and humorous speaker on the world of design as well. His work has appeared in Architectural Digest, Art & Antiques, House Beautiful, Kiplinger’s, Horticulture Magazine, Designs for Living, Metropolitan Home, Better Homes & Gardens, The Journal of Light Construction and many more.
Randall appears regularly as a guest expert on the Discovery Channel, CNN, HGTV and Martha Stewart Living Radio. He also writes a monthly column called “The Last Word in Lighting” for Residential Lighting Magazine, answering homeowner’s and designer’s questions on lighting.
Randall has written 7 books on the subject, including Residential Lighting, A Guide to Beautiful and Sustainable Design which is an informative…and entertaining reference book for home and garden lighting.
His latest endeavor takes him back to his photography roots. It is a compelling collection of images called Lost Dolls, The Hidden Lives of Toys.
Green Building Practitioners are noticing three trends that, while not new concerns, truly speak of the momentum gathering within the sustainable design movement. One is the issue of water scarcity, second is the issue of environmental chemicals emitted by and residing in our built environment and third is the interest in adding the component of social justice to our battery of integrated building design strategies. I see these three paths as critical components of a broadening new way of practice.
At GreenBuild last month, I attended several sessions given by lawyers, educators, builders, planners, engineers and architects on the issues of water efficiency and maximization. Some common themes surfaced throughout the presentations. Most salient were:
The relationship of water and energy. Known as “watergy” or “embedded water,” it is interesting to note that treating and conveying water is not only the most expensive component of the cost of water, but also the most energy intensive. We must start to connect our water use policy with our energy policy and to find more energy efficient ways to deliver water to and within buildings.
The end of landscaping.Solutions to current water scarcity involve incorporating at least 50% of appropriate, climate adaptive plant species as part of the landscape and providing alternative means of irrigation through captured rainwater and stormwater and building-issued greywater. Municipal water should be thought of as a supplementary, rather than primary, source. The era of the fantasy landscape is over.
We must stop using drinking water to flush waste. Other sources water are on site greywater, rainwater, municipal reclaimed water, mechanical water (from blow-down or condensate) and blackwater.
Centralized wastewater treatment is wasteful and inefficient. Wastewater treatment plants need to be localized, even to the neighborhood scale. They should be thought of as a source of renewable resources, as they offer opportunities to harvest nutrients such as ammonia, nitrogen and phosphorous rather than expend dollars on their removal and disposal. Our infrastructure needs to be re-vamped from a combined sewer system to a split wastewater/stormwater management system. Because wastewater is electron-rich, it is also time to start thinking of wastewater treatment plants as sources of energy.
What does this mean to green designers? It means that landscape designers need to concentrate on species selection and water infiltration. An example of this “spread and infiltrate” strategy is to divert runoff to a series of tree planting basins or rain gardens. For architects and builders, this means a new way of assessing how we convey water to, in and around buildings. Is the building a treatment facility? Has a water budget (catchment area multiplied the amount of rainfall) and water footprint been calculated? How do we design to make conservation easier for the user?
rainwater harvestingrainwater tank
Barriers:Several barriers compound the challenging issue of maximizing water efficiency. Water prices are artificially low, thus stymying innovative technologies. Another barrier is the apprehension about using greywater indoors due to insufficient treatment of potential contaminants. Last, current rating systems do not consider water issues as a whole. LEED splits water credits into two categories of credits, sustainable site and water efficiency. Rating systems should focus on more than just fixture selection, irrigation controls and stormwater diversion. It’s time to think of water design on the community level, as holistic, land-based management, as a watershed, that will steer building design, community design and infrastructure planning to a greener, more water-abundant future.
Marian Keeler, Assoc. AIA, LEEP AP is the author of Fundamentals of Integrated Design for Sustainable Buildings, Wiley, 2009.
It’s Saturday morning laundry time. The washer spins and shakes, clothes are cleaned while the dirty water flows outside to irrigate fruit trees. There’s something satisfying about this
simple shift: a slight change in a mundane chore has reduced water consumption, taken a load off the sewer treatment plant, promoted food security, and saved time and money.
Over the past few decades reusing water from showers, sinks, and washing machines, called greywater reuse, was mainly embraced by the “do-it-yourself” community. Handy people rerouted their pipes, diverting this resource away from sewers and septic systems, out to trees, bushes, and other landscaping. Though popular, all this was technically “illegal”, surprising in a state like California, fraught with drought, water rationing, and proposals to spend billions of dollars on new dam construction.
Greywater use is regulated by the state plumbing code, which historically was very restrictive and made it overly expensive or outright impossible for people to get permits for greywater. This resulted in almost zero compliance of the code (of the estimated millions of greywater users in the state, there were only a few hundred permits), a lack of professional installers, and a huge amount of misinformation about the best ways to reuse greywater.
In 2008, Alan Lowenthal, a State senator from Long Beach, CA, wrote a “Shower to Flower” bill (SB 1258) that mandated a code rewrite of the old greywater code, moving regulatory power from the Department of Water Resources (DWR) to the Department of Housing and Community Development (HCD). HCD convened a series of stakeholder’s meetings to gain input from greywater experts, health departments, building departments, water districts, and other concerned citizens, as well as analyzed existing studies and codes on greywater.
Recipe for a code change:
* 3 stakeholders meetings in Sacramento
* hundreds of letters, emails, and phone calls in support of a friendly greywater code *drought
* increased water rates
* mandatory water rationing in many districts
*extensive time and research from HCD staff
*greywater friendly codes examples in Arizona, Texas, and New Mexico
*media coverage of greywater success stories
*green job potential
Mix ingredients together during a time of “drought emergency”, sprinkle a few newspaper articles about people successfully (yet illegally) saving thousands of gallons of water with simple, safe systems, add a dash of green jobs potential in a failing economy,
season with forward thinking individuals in charge of the process.
Results: A new greywater friendly code
The new code removed barriers for simple, low cost greywater systems. Now washing machine systems do not require a permit, only compliance with state-published guidelines, and no inspection. Permits are still required for systems that alter existing plumbing, larger systems, and the section of code governing indoor reuse is not complete.
Gardens are flourishing
The biggest effect of statewide greywater reuse, aside from the happy plants, will be the ability of professionals to incorporate greywater into their business Landscapers like, Deva Luna from Earthcare landscaping in San Jose (www.earthcareland.com), offers greywater to clients. Other gardeners like David Mudge from David Mudge’s Gardens in Martinez, California, use greywater as part of sustainable permaculture design practices.
a greywater garden
The greywater goes out of the house through the floor and travels across the crawl space underneath the house. The auto-vent is inside the house since it needs to be at the high point of the greywater line.
Our water future
While greywater policy advances, California water policies lag behind. State government and local water districts continue to seek out unsustainable sources of water; from destructive new dams, overdrawing from rivers and ground water, costly desalination plants, and expensive recycled water. As regulatory barriers are removed, decision makers need to include and promote sustainable practices such as greywater reuse, rainwater harvesting, and waterless toilets as a path to a sustainable water future.
There are a few things people could do.
1. Write a thank you note to HCD for the new code: James Rowland email@example.com
2. Write to the local building department/inspectors/city council telling them how happy you are that it’s easier to install legal greywater systems and encourage them to support greywater use. (possibly by promoting it with education, demonstration projects, information on their websites, etc.
Laura is a founder of Greywater Action and has spent a decade exploring low-tech, urban sustainable water solutions. She has a BA in Environmental Science, a teaching credential and a masters in education from New College of CA. She is a co-editor of the anthology Dam Nation: Dispatches from the Water Underground
Greywater Action offers presentations and hands-on classes on sustainable water use technologies. See www.greywateraction.org for more info.
- Grant Street house
Most buildings leak air, and therefore heat, through cracks in their building envelope. We get cold in our leaky buildings and turn up our heaters to keep warm. The heat continues to leak out, and we continue to turn up our heaters, and on and on the cycle goes. In the end, we may as well be burning our money to keep warm. Our building systems clearly aren’t working as well as they should for us or for the environment, which begs the question: Why aren’t we doing more to change this trend?
Actually, some of us are. Slowly but surely, people are building Passive Houses that use around 80% less energy, while keeping us warmer and more comfortable than drafty, conventional homes do. But even this is not enough.
It is critical that Architects, designers and builders begin applying the Passive House Standard during the design stages of their projects. Just as engineers must predict how buildings will survive earthquakes, designers should be using energy modeling tools to predict the energy consumption of buildings before they are ever built.
One of the most valuable tools to emerge from the Passive House Standard is an energy modeling tool called the Passive House Planning Package (PHPP), which for years has accurately predicted the energy needs of hundreds of Passive Houses built in Europe.
It makes the most sense to design with Passive House concepts in mind in the design phase of a new building, when it is easiest to accomplish, however it is also possible to apply these concepts to existing homes if a major remodel is in the works. The key areas most important to achieving a Passive House are:
BUILDING ENVELOPE & AIR-TIGHTNESS: The strategy is to focus first on the building envelope so that it optimizes heat gains and minimizes heat losses. The insulation system should be continuous from the bottom of the foundation to the top of the envelope. A designated layer should be continuous from top to bottom in order to achieve air-tightness.
FRAMING: The framing system should conform to all the structural requirements and be designed using Advanced Framing Techniques that eliminate unnecessary wood members and replace them with insulation.
DOORS & WINDOWS: The specified performance of the doors and windows, and their installation methods, should be synchronized with the climate requirements, as well as the orientation and design of the building envelope in order to optimize heat gains and minimize losses.
VENTILATION: A ventilation system with a heat recovery component should be installed to circulate fresh air 24 hours a day, while transferring the heat from stale outgoing air to fresh incoming air. Free heat generated from lighting, computers, household appliances and people is recycled so we don’t have to blast our heaters to keep warm.
- heat exchanger graphic
After follwing these design and construction strategies, every building designed to the Passive House Standard is comfortable, sustainable, and requires far less energy to run than a conventional home. Our Grant Street home in Berkeley, CA was the first residential retrofit project in the US with the goal of meeting Passive House Standards.
Grant Street house AFTER
- Grant Street house BEFORE
- front elevation close-up
- front door
- back cantilever
- Grant Street house cabinetry
- Grant House kitchen
To find out more about Passive House standards and the success of our remodel, visit our website at www.bautechnologies.com or contact us at 415.526.2777.
Peter Rich of Peter Rich Architects in South Africa has dedicated his career to the service of the less privileged. His projects include low-income housing, community centers and children’s facilities. The Mapungubwe Interpretation Center in Limpopo, South Africa, a project recently completed, looks to the local culture and ecology for its design inspiration. Situated in the site of an ancient trading civilization at the confluence of the Pimpopo and Shashe rivers the in Mapungubwe National Park, the building houses artifacts from the region’s early pre-historic civilizations and reflects the complex natural landscape around it in both form and materiality.
Employing parabolic curves made from locally sourced and fabricated rammed earth bricks, the resulting structure is both elegant and sustainable. Rich worked with local residents during the design and construction process, teaching them how to manufacture the stabilized earth tiles and how to construct the vaults and arches. These vaults, called Timbrel vaults, create a composition of light, billowing forms that seem to peel away from the structures below, revealing the history inside. The building is contained by two hollow cairns, which are reminiscent of the route-markers found in the native South African cultures of the region.
The building, both in its creation and in its final end use is deeply rooted in its site both culturally and physically. The center is meant to not only display the cultural history of the site, but also to elicit a better understanding for the vulnerability of the local ecology. The building has been nominated for several awards including the Holcim Award for Sustainable Construction in 2008. The structure won the World Building of the Year at the World Architecture Festival in Barcelona, 2009, being praised by the jury for its ‘hand-crafted intelligence, use of local materials’ and the way it “handled issues of sustainability and its relationship to the landscape, responding to vernacular African styles’.
Plus Energy Settlement Weiz, Germany architect: Erwin Kaltenegger photo: Gunter Lang
- photo: Binder Holz
photo: Binder Holz
The San Francisco Bay Area is rich with examples of Green Architecture, and is arguably on the forefront of the green building movement. Many people here have heard of the Passive House Standard, but not many really know what it is or how it works.
In essence the term “passive house” represents the idea that these houses do not need to rely on large, conventional heating systems that require lots of energy to provide heat. Instead they passively recycle the free heat generated from sunlight and activities within the home, and are supplemented by smaller heating systems that require far less energy to run. Turning lights on, running the refrigerator, cooking, using a computer, and the people provide a constant source of free heat. This heat is contained inside the building envelope and is recycled by transferring it from outgoing stale air to incoming fresh air through a heat recovery ventilator. The houses are so well insulated and air-tight, that warm air does not escape through the building envelope and cold air isn’t allowed to creep in.
If you compare a Passive House with a conventional home, a Passive House is up to 80% more energy efficiennt, indoor air quality is superior, and the buildings themselves are more comfortable to live in since the temperature does not fluctuate.
It is critical that we start applying t he Passive House concept before relying on alternative energy sources such as solar or wind energy. Think of it this way: only using solar power as a remedy against energy waste is similar to resolving the problem of a leaky gas tank by ignoring the leak and filling up with biofuel instead of gasoline. It might make us feel better, but it doesn’t change the fact that our gas tanks are leaking and energy is being waster. They help, but ignore the core problem, which is our buildings are energy hogs.
Here in the Bay Area, where our climate is relatively mild, it is one of the easiest places to reach Passive House standards. We have no excuse for building structures that waste heat and require us to turn on our heaters. In summer, we can turn off the heat-recovery ventilator and throw open the windows and doors to enjoy the nice weather. In winter, the mechanical heat-recovery ventilator can be used to allow the building to “breathe” without wasting energy. Fresh, filtered air is circulated 24 hours a day, resulting in better indoor air quality and energy efficiency.
Buildings are responsible for 40% of all energy consumed and Green House Gas emissions. Clearly, the building sector needs to reverse this trend to avoid the possible catastrophic consequences of climate change. The best way to achieve this is through energy efficiency. The Passive House Standard has been tested throughout Europe over the last 15 years and is a proven strategy. Researching this standard and adapting this know-how and experience to our building industry is the fastest path to designing and building projects that perform to higher standards of energy efficiency, comfort and improved indoor air quality.
photo: Internorm Windows
photo: Internorm Windows
Nabih Tahan, AIA, MRAI is a licensed architect who returned to Berkeley from Austria to remodel his home while demonstrating sustainable design and construction techniques being used in Europe. He is the founder and a principal of BauTechnologies.