Not General Electric’s home of the future, this demonstration project, scheduled for construction in 2010, envisions a home that is completely energy neutral. An eight kilowatt solar array, grid connected and net metered, will produce all power necessary for domestic and transportation purposes, without any on site carbon emissions. The owner, who has been working in the solar industry for over twenty years, is committed to, ‘getting off the pipe, a house without a gas meter.” The basic design strategy is to create a responsible intervention in an historic setting, acknowledging the context while at the same time embracing a contemporary vision of space and function. It includes a structure with ample roof area for the panels and a highly efficient envelope. The space planning places open living spaces at the rear of the house directly adjacent to the garden. These rooms employ ample, south facing glazing for maximum solar gain. On mild days, exposed concrete floors with radiant tubes convey passively collected heat to the north facing portions of the house via a small re-circulating pump. We have specified Marvin wood windows with High-R-Tripane glazing and sprayed, Biobase, soy foam insulation for R-19 walls and an R-40 roof. This creates a tight enclosure while also accounting for existing, historic “blind walls” and the inherent problems with air and moisture infiltration that they present. A three-story stair well, topped with operable skylights is a dramatic vertical space and creates a “heat stack,” providing all cooling necessary for the moderate San Francisco climate. The mechanical systems are based on the “all electric” concept. In the active heating mode, a 2/3 ton, electric heat pump provides hot water for the floor system. A second heat pump provides domestic hot water. LED fixtures and high efficiency appliances lower the total electrical load, while a plug-in hybrid charges in off hours to balance production and consumption cycles with the net metering approach. In an effort to embrace a holistic approach to sustainability we have included a gray water reclamation system. It will provide irrigation for a shared, backyard vegetable garden and for drought tolerant, landscape features both at the yard and the street. In this urban setting, this project represents an initial attempt to do more than “green” the structure, we are working at the level of lifestyle, beginning to think about transportation, food production and community as component parts of the architectural response.
Architect: Ross Levy, LSarc
Associate: Karen Andersen, LSarc
Structural Engineer: Shaun Monyihan, SEMCO
Mechanical Engineer: Bill Dakin, Davis Energy Group
Paper bags and cardboard boxes, butchers’ paper and newsprint hats. Paper plates, papier mache and the versatile matchbox, boxes for packing and moving and play Visionaries like Gehry and Shigeru Ban use it for structure but, whether the blame rests with neat stacking Lego and Lincoln Logs or span-worthy Meccano, most of us don’t consider cardboard as a construction basic.
With around 85% recycled content typically found in corrugated card, the material offers sustainable credentials that many other product and building materials cannot match. Frank Gehry’s seminal 1969 Wiggle chair, featuring 60 layers of corrugated card “Edge Board” screwed into compression, is a plain sexy investigation of how to achieve strength and sculpture through the opposite layering of corrugations. Shigeru Ban’s equally groundbreaking use of cardboard structure in halls, office buildings and houses epitomizes economy in use and lifecycle, marrying the strength of the helically wound paper tube with simple, repeatable, affordable connection details. As the architect says, “I don’t like waste”.
- Wiggle Chair
Shigeru Ban’s temporary studio, Pompidou Center
Online a smattering of origami-based modules demonstrates all manner of flat packing structure. Bloxes, flat packed card blocks that interlock for DIY internal walls and structures. Swiss architect Nicola Enrico Staubli and his free, downloadable Foldschool designs. Eschewing the asymmetrical fold for the uniform concertina, the patented Liquid Cardboard creations of US-based Cardboard Designs are poetic and “freely transforming” vessels.
Wall of Bloxes
More pedestrian in form but super useful, compressed paper panel materials like Paperstone and EcoTop provide a paper-based replacement for pulp boards like MDF, utilizing the density and strength of papers en mass.
The ultimate in DIY cardboard emersion and superior acoustics has to be Mafoombey, a corrugated space both poetic and functional, designed for listening to music as part of the Finnish Habitare Fair 2005 by students Martti Kalliala and Esa Ruskeepää. In awarding Mafoombey first prize Jasper Morrison commended the design for simply “turning the humble material of cardboard into something so wonderful”.
California Poppy Reserve March 2009
When excavation is required, take care to preserve existing top soils, to set them aside in the order in which they were removed. Value and protect site soils during the construction process and return them to the land as close to their original place as possible when construction allows. Cover site soils with organic mulch during the construction process to a depth of at least 6 inches to prevent the intrusion of invasive species. Keep the soils cool and encourage microbial activity.
Landscape with native plants, particularly plants selected from the plant communities of the region. When soils are protected and allowed to return to their native state, we are designing for the protection of the natural world. Healthy native soil is a sponge. It absorbs rain and slows down run-off. It stores and releases water and nutrients as plants require them. It filters, traps and ultimately breaks down urban pollutants such as oil, metal and pesticides. It also filters and purifies the air and water that percolate through it. It perpetuates life on the Earth by supplying valuable nutrients and antioxidants to plants.
Disturbed soils invite invasive plant species to thrive. Invasive plants affect water quality, species diversity and populations, reduce favorability for species reproduction, and reduce available food sources. Invasive plants accelerate soil erosion and stream sedimentation, absorb precious water sources and affect water quality.
When an exotic plant invades a soil community, it can alter the links between the plants and organisms that are above the ground and the plant parts and organisms that are below the ground.
A billion soil microbes are found in one teaspoon of soil. Perhaps of those billion soil microbes, there are 4000 different species of bacteria, fungi, nematodes and protozoa. The bacteria bind the finer soil particles together. These become micro-aggregates bound together by fungal vegetative growth. The abundant presence of these symbiotic fungi leads to substantial increases in the nutrient uptake of host plants. Because mycorrhizal fungi can have affects on both individual plants and plant communities, when an invasive plant is able to alter their dynamic, this may affect the long-term relationships of many plant species in a forest.
Exotic plants can directly alter the physical properties of the soil and the attributes of an ecosystem. Certain invasive plant species literally transform ecological communities.
Chaparral garden with a gravel driveway
Grassland and chaparral garden
If we hope to create truly sustainable communities, understanding and protecting local ecosystems for future generations can only be accomplished when we restore our native soils by selecting plants that have evolved in those soils for millions of years. If you’d like to view the article in its entirety, please click on www.middlebrook-gardens.com
Alrie Middlebrook is a committed advocate and practitioner of the sustainable lifestyle, respected landscape professional and California native plant specialist. Her San Jose, California-based build/design firm, Middlebrook Gardens, has installed over 250 California native gardens and remains on the leading edge of the rising sustainability movement.
Information Based on Euro Panels Overseas Literature.
The basic section of an external wall construction composed in accordance to the VIRSC principle consists
1: a load bearing structure
2: a layer of thermal insulation on the outside of the load bearing structure
3: a ventilated air gap / cavity
4: intermediate supporting structure to connect the load bearing structure and the architectural panel
5: an architectural panel
The ventilation (circulation of air) is created in the cavity by leaving an open joint at the bottom and the
top of the cladding. This principle must be followed consistently meaning e.g. that air in- and outlets
should also be designed below and above windows
PREVENTION OF INTERNAL CONDENSATION
In cold seasons the partial vapor pressure inside the heated building is higher than outside, leading to a
transport of vapor through the outside wall. This vapor could condensate in the air gap against the back
of the architectural panel but the dry air that circulates through the cavity will eliminate this moisture.
COOLING EFFECT IN THE SUMMER
A very large portion of the solar radiation energy is dispersed before it even reaches the thermal insulation
– Depending on the color used, some radiation will be reflected.
– The temperature of the panel itself increases, which consumes another part of the incoming energy.
– At last, the air in the air gap is heated up, creating a chimney effect that conveys continuously fresh
outside air into the cavity, cooling down the whole construction.
NO THERMAL BRIDGES
Because the insulation is applied outside the supporting structure, this creates a continuous thermal barrier,
so that thermal bridges and their associated problems – such as surface condensation and consecutive
creation of unhealthy mould growth – are avoided.
NO RAIN REACHES THE THERMAL INSULATION OR THE LOAD-BEARING
The outside wall cladding functions as an umbrella, so the internal construction remains dry. Moisture
penetrating the cavity either runs down the back of the architectural panels or is removed by natural
LOW TEMPERATURE VARIATION IN THE LOAD-BEARING CONSTRUCTION.
Normally one tries to achieve a stable interior temperature but can not influence the exterior temperature
variations. By installing the thermal insulation material on the outside of the load bearing construction, the
biggest variation of temperature will occur inside the insulation material leaving only minor temperature
variations in the interior wall. In this way the interior structure is protected from high thermal stresses and
so the risk of cracks is reduced.
DIMENSIONAL STABILITY OF THE CLADDING MATERIAL
Because the architectural panel is ventilated both at the front and at the back, there is almost no differential
hydrothermal load working on it. This results in a stable panel behavior.
The supporting structure onto which the architectural panels are fixed can be made of:
– galvanized steel
– stainless steel
Article by Jay Leathers of Foundry Service and Supplies, Inc. Foundry Service and Supplies, Inc. is a Distributor and Fabricator of high-density fiber cement board products for the Western United States for American Fiber Cement Corporation. American Fiber Cement Corporation is the Master Distributor for the United States of America for Euro Panels Overseas (manufacturer). www.foundryservice.com; www.americanfibercement.com; www.europanels.be
Select a rainwater vessel for maximum LEED points and maximum karma.
Good on you for deciding to capture and reuse rainwater and take a load off city systems! Saving water, saving “watergy”- the energy to used to push city water around the grid – and unloading the stormwater system downstream are just some of the benefits of rainwater harvesting which contribute to your karmic wellbeing and your water use bottom line.
Just as important in the green scheme of things, but often far less considered, is the vessel you choose for collection. “Green” credentials and contributory LEED points vary hugely between rain barrels, cisterns (also known as tanks) and other rain storage vessels. Like most consumer products, a cheap $/gallon price is not often the indicator of value or best sustainable practice. Just as the BPA debate has remodeled the drinking bottle landscape, a reconsideration of the material makeup and lifespan of rain-holding vessels is bound to shake up rainwater harvesting.
PVC bladders are an unquestioned under-house rain storage solution in Australia, yet many European countries and US cities have banned PVC for its severe end of life repercussions. The toxic dioxins released when PVC is produced or burned are suspected carcinogens thought to also bio-accumulate and cause long-term harm to animals and humans.
THE GOOD – saves space, cheaper freight
THE BAD – puncture or rodent incursion, stands are easily destabilized, some serious end of life issues
THE UGLY – The US Green Building Council states that “PVC (is) consistently among the worst materials for human health impacts…” and is considering a LEED credit for avoiding PVC.
LEED status- So a future point for NOT using PVC! Although you may theoretically achieve the two rainwater harvesting LEED points, city laws and possible upcoming LEED changes would suggest that other materials are a better choice for your rain containment.
Steel cisterns – corrugated or straight-walled –will feature a food grade bladder or bonded polymer lining unless they are made of stainless steel. Many steel cisterns larger than 9ft wide have a PVC or stainless steel center prop for additional support. Although steel cisterns have high embedded energy and water costs, some of these can be offset by recycling the steel at the end of its life. A stainless steel cistern is fully recyclable, whilst a lined steel cistern would need to have the bonded layer removed an thus is not technically 100% recyclable.
THE GOOD– large capacity, recyclable, wide range of shapes including slimmer profiles, wide range of colors, good in bushfire, repairable
THE BAD – can corrode, cannot be moved without potentially compromising its structure, radii constraints mean a steel cistern is never truly “slim”
THE UGLY – all depends on your aesthetic
LEED status – 2 contributory points for the rainwater harvesting and a possible point if the design is modular or otherwise innovative
Concrete water cistern
Concrete cisterns contain up to 50% steel content, making their environmental footprint a chunky one and making recycling of both steel and cement a harder task. Heavier to handle and transport, concrete cisterns come into their own with sheer capacity and with their ability to handle bushfire. Although they are weightier, the anticipated lifespan of a concrete cistern is still 20 years, the same design life as a high quality plastic or steel cistern.
THE GOOD – robust, structurally useful, can withstand fire, no internal bladder, keeps water cooler than other above ground rainwater vessel options
THE BAD – can crack and corrode over time, heavy, unwieldy to handle and install, large environmental footprint, difficult to separate materials for recycling at end of life
THE UGLY – precast concrete has a monolithic, industrial look which you either need to work the architecture with, or hide.
LEED status – 2 contributory points for rainwater harvesting, possibly an extra if you can work the cistern into a design to harness the thermal mass.
And finally, plastic cisterns. Usually made of polyethylene which is petroleum-based, the sustainability of a plastic cistern ranges enormously from blow-moulded recycled food barrels with a working life of less than three years to robust ¼ inch walled rotationally molded cisterns designed with inbuilt UV stability for 20 years or more of useful life. Unlike Australia the USA does not regulate that rainwater tanks must be made of “virgin” food grade material, so many barrels and cisterns use recycled content which is “greener” upfront, but can heavily reduce the lifespan of a vessel. Reusing food grade barrels for example requires that the vessels are emptied and bleached every year, negating the reuse benefit with the requirement for chemical treatment. Other plastic vessels are so robust that they are designed to be reused several times over their life. Theoretically polyethylene is recyclable at the end of its life but the jury is out on whether UV light renders 20-year-old plastic recyclable or not.
THE GOOD – lots of choice in shape and function, durability (some models), slim lines (depends on design), integrated color and inbuilt UV stabilization, easy to install (the smaller ones)
THE BAD – inferior quality makes many of the lower cost barrels next year’s landfill, thin-walled designs prone to puncture
THE UGLY – plastic vessels not made with UV stabilization will need to be painted regularly, algae will flourish in barrels with open tops, requiring yearly chemical cleaning
LEED status – from a basic 2 points for rainwater harvesting up to 8 contributory points if the vessel has innovative features and the potential for reuse. Rainwater HOG modular tanks, shown above in black and yellow on a school building, have been known to garner 9 contributory LEED points under LEED for New Homes.
Rain barrel installed
The slew of rain-holding solutions on the market offers a wealth of choice for those who wish to collect and reuse rainwater. Look for long life, robust, durable, UV resistant materials, and if possible look for something you are able to add to or reconfigure as your circumstances and water needs change. Think about how you choose the other essential appliances in your home and apply it to the purchase of your rainwater solution. As rainwater collection and reuse becomes the status quo across the USA those who take the time to navigate their rainwater vessel options will discover that the simplicity of rainwater capture in an appropriately sustainable cistern is a reward for life.
Sally Dominguez is an award-winning inventor, a published architect and an educator in sustainable design. Sally judges invention on ABC TV’s New Inventors and writes for a number of Australian publications on a range of sustainable design and material issues ranging from offgassing in vehicle interiors to green roof options and cardboard structures. See and read her work at www.beautifulusefulgreen.com
Although much has been written about passive solar design, and some mention is made of selecting glazings appropriate to the building aspect, sourcing windows with glazing both optimized for passive solar buildings, and reasonably priced can be less than straight forward. Window manufacturers in the U.S. tout the insulative properties of their windows (their u-value) to reduce heating loads, and how well they exclude solar heat (low Solar Heat Gain Coefficient, or SHGC) to reduce cooling loads. Both of these qualities are achieved with a combination of double glazing, and low-e coatings. However, by using glazings optimized for low u-value and high SHGC, south facing windows can contribute significantly to the winter heating of a house. Most factory wood and clad-wood window offerings in the U.S. only include low-e glazings optimized to exclude solar heat. This is presumably because the vast majority of homes are designed without regard for the sun, a single window brand may be distributed across very diverse climate zones, and the prescriptive energy codes dictate low u and SHGC values, but give no credit for passive heating. It is easier to offer a handful of glazings which will work reasonably well at meeting code, at the lowest cost, in both heating and cooling dominated locations.
On one of our first passive solar designs to be built we clearly told the client (and builder) that they needed to chose glazing appropriate for the window’s aspect. She chose one of the premier residential window brands for her new guest house and art studio, located in the high desert of the southern Utah. During the first winter the building was occupied she contacted me wondering why it required more supplemental heating than I had predicted. Upon investigation, I realized the window’s high performance glazing was as described above, and excelled at heat exclusion. Since then we have designed a number of homes in that neighborhood, all of which successfully use tuned glazing, and which perform as designed.
Fortunately, there are a few windows available well suited to passive solar homes, and hopefully more in the future. All these companies offer glazings suitable for non-south windows as well. Loewen offers an array of double and triple glazings, including triple clear which meets code minimum for u-value in most climate zones, and offers a high solar heat gain coefficient (SHGC). Eagle windows are available (although this isn’t mentioned in their literature) with Alpen’s heat mirror glazings, which have suspended films tuned for different purposes. Experience with ordering this seems to vary between dealers. Cardinal recently introduced a low-e film optimized for solar heat gain, Low-E 179. Semco offers it as an option; ask and encourage other brands who use Cardinal glazing to do so. Serious Materials is a relative newcomer whose offerings look very promising, addressing glazing tuning as well as overall window efficiency. A number of high performance Canadian fiberglass windows are available as well, although at a significant premium.
A high SHGC glazing can let in over twice as much heating energy as a glazing optimized for cooling, with only a small reduction in insulative performance. After designing a passive solar home with a large collector area of south facing windows, appropriately shaded in the summer, take the time to spec appropriate windows, and educate the client and contractor about the importance of the glazing choice.
Kalen Jones is a founder and principal at With Gaia Design. With Gaia provides sustainable architecture and landscape architecture design, consulting, and education services. Their focus is passive solar homes, civic and commercial site design.