photo: Emily Hagopian (www.EmilyHagopian.com)
As architects, we weave the complexities of program, design, regulations, technology, budget and fee, while managing clients, projects, and liability. Proposed changes to our workflow frequently interrupt our momentum. Changes to our design process that seem burdensome ultimately transform our work and improve our buildings. The process of commissioning is new to many of us, and we are finally learning how to make it an effective design tool.
USGBC introduced commissioning to us by way of LEED-NC EA prerequisite 1: Fundamental Commissioning, and EA credit 3: Enhanced Commissioning. For most of us, our first question was, ”What is commissioning?” Fortunately there are several resources and industry experts, who are helping us understand this improvement and clarification to our evolving design process.
Let’s start with some definitions:
Building commissioning (Cx) provides documented confirmation that all building systems, including mechanical, electrical, lighting and controls function according to criteria set forth in the project documents to satisfy the owner’s operational needs.
A commissioning agent (CxA) typically provides commissioning services as a consultant to the owner. On some LEED projects the CxA is hired by the architect.
There are several documents that must be sequentially produced in order to satisfy LEED requirements:
Owner’s Project Requirements (OPR): Produced by Owner with Design Team & CxA assistance
Basis of Design (BOD): Produced by Design Team with CxA assistance
Commissioning Specifications: By Architect/Spec Writer with CxA/ LEED Consultant assistance
Commissioning Plan: Produced by Contractor with CxA assistance
Installation Verification & Performance Testing: By CxA & Installing contractors
O&M Staff Training: By Installing Contractors & CxA
Building Manual: By General Constractor with CxA assistance
Summary Report: By CxA
The intent of the commissioning process is to create the Owner’s Project Requirements (OPR) along with the program during pre-design. Unfortunately, most projects are well into design development or construction documents before a LEED consultant is hired and the commissioning process begins. So, ultimately the OPR is merely an exercise to satisfy LEED rather than being a useful design tool.
In an “integrated design” process, commissioning begins during pre-design. Architects must coach their clients to complete the OPR during pre-design. Once the OPR is created, then the design team, led by the architect and engineers with the assistance of the CxA (or LEED consultant on small projects), produces the Basis of Design (BOD). From the BOD flows the project specifications, which require a commissioning section in addition to a LEED requirements section. As the design changes, the OPR and BOD should be updated to reflect those changes.
At the beginning of construction the contractor takes the lead by producing a Commissioning Plan, which is outlined in the specifications. The CxA will facilitate a pre-construction meeting with the installing contractors and engineers to establish expectations and ensure that the design intent and commissioning requirements are understood. The CxA will work with contractors during installation and start-up as required to meet LEED requirements. Performance tests and construction photos provide backup documentation, which must be available for audit by USGBC.
At the completion of construction a building manual will be produced by the contractor. O&M staff must be trained along with full time occupants of the facility. The CxA will produce a Commissioning Report, which summarizes the entire Cx process for the project. Frequently, this report is the last document uploaded into LEED online before the construction phase submittal to USGBC. Add another 5-8 weeks before the project received certification from USGBC.
We recommend the following resources for additional information and instruction:
EDR Commissioning Handbook & Online Templates www.energydesignresources.com
USGBC: Who Can Commission? www.usgbc.org/ShowFile.aspx?DocumentID=1262
Commissioning On Purpose, by Coleman & Coleman www.eeiengineers.com
US Dept. of Energy Building Toolbox www.eere.energy.gov
Commissioning Resources www.michaelheacock.com/toolslinks/commissioning.html
Michael Heacock + Associates is a LEED consulting firm with offices in San Francisco and Santa Barbara. Their work includes schools, commercial, public, institutional and residential projects.
The techniques of lighting have greatly evolved beyond simple table lamps and chandeliers, yet many homeowners have not updated their thinking much beyond this approach. So much of what we see in current design magazines and books are the ultra modern, ultra clean interiors. It’s true that progressive design is a hot topic, but it’s not for everyone. How does the owner of a more traditionally styled house make use of today’s lighting techniques? Can new lighting techniques be applied to non cutting edge spaces to enhance the sense of warmth and comfort that these cozy interiors inspire?
The answer is a resounding…yes
The trick is to keep the lighting upgrades subtle so that the decorative light sources can remain the architectural jewelry for a home. Chandeliers and table lamps are an important element to most all styles of residences. They are needed to provide the ambiance for a room without necessarily providing all the necessary illumination on their own. This applies outside of a home as well. Adding a layer of accent lights, hidden among the plantings, allows the lanterns at the front door and by the garage to provide the illusion of providing the main light without visually over powering the landscaping.
Sometimes residential lighting design takes a backseat to wondrous commercial projects as far as eye catching design goes. Lighting for homes needs to be more subtle than what goes into public spaces. A restaurant or theater project can dive headfirst into the realm of fantasy design. Patrons want to be transported to a place that is a different world than what they experience at home. Yet, when homeowners are in their personal spaces they want to be able to have various levels of functional illumination for the mundane, but ever so important tasks, that are a part of day-to-day living.
Lighting can be a tremendous force. It’s the one factor that makes all the other elements in design work together. Yet it has for so long been the last thing considered and the first item cut from budget. The result has left many homes drab, uncomfortable, and dark. Too often the blame goes elsewhere, when improper lighting is the true culprit. Becoming better acquainted with the components of good lighting will allow homeowners to communicate their needs more clearly with the sales staff in lighting showrooms and the contractors whom they have hired to do the installation.
Light has four specific duties. They are to provide decorative, accent, task, and ambient illumination. No one light source can perform all the functions of lighting required for a specific space. Understanding what these terms mean will help homeowners make better decisions that will integrate illumination into the overall design and give them what they want. Here is a description of these four functions that puts them into terms that can be easily understood by everyone involved:
Light fixtures such as chandeliers, candlestick-type wall sconces, and table lamps work best when they are used to create the sparkle for a room. They alone cannot adequately provide usable illumination for other functions without overpowering the rest of the design aspects of the space. I call them the supermodels of illuminations. Their only job is to look fantastic.
For example, a dining room, illuminated only by the chandelier over the table, creates a glare-bomb situation. As you crank up the dimmer to provide enough illumination to see your guests, the intensity of the light source causes everything to fall into secondary importance. This one supernova of uncomfortable bright light eclipses the wall color, the art, the carpeting, and especially the people sitting at the table.
By nature, any bright light source in a room or space immediately draws people’s attention. They won’t see all the other elements, no matter how beautiful or expertly designed. For example, linen shades on table lamps draw too much attention to themselves when they are the only light source in a room. Consider using a shade with an opaque liner and possible a perforated lid to help direct the illumination downwards over the base, the tabletop and across your lap for reading. We’ll cover this in a little more detail in the section on task lighting below.
Accent light is directed illumination that highlights objects within an environment. Light sources such as track and recessed adjustable fixtures are used to bring attention to art, sculpture, tabletops and plantings. Just like any of the four functions, accent light cannot be the only source of illumination in a room. If you use only accent light, you end up with the museum effect, where the art visually takes over the room, while the guests fall into darkness. Subconsciously, the people will feel that the art is more important than they are.
Good accent lighting thrives on subtlety. A focused beam of light directed at an orchid or highlighting an abstract painting above a primitive chest can create a marvelous effect. People won’t notice the light itself; they see only the object being illuminated. The lighting effect achieves its magic through its very invisibility.
In the movies, if we can tell how a special effect has been achieved, we feel cheated. We don’t want to know, because we want to think it’s magic. In lighting, it should be no less the case. We want to see the effects of light, but the method needs to remain unseen. That subtlety is what will give the design a cohesive wholeness, allowing the architecture, the furnishings and the landscape to become the focus in a particular space, not the decorative fixtures or the bulbs glaring out from within them.
This is illumination for performing work-related activities in the home, such as reading, cutting vegetables, and sorting laundry. The optimal task light is located between your head and your work surface. That’s why illumination coming from above isn’t a good source of task light, because your head casts a shadow onto your book, computer keyboard, or recipe book.
Table lamps with solid shades often do the very best job for casual reading, because they better direct the light and don’t visually overpower the room when turned up to the correct intensity for the job at hand. Fluorescent or incandescent linear shelf lights too, are a good source of task illumination at a desk with a shelf located above the work surface or in the kitchen when mounted under the overhead cabinets.
Ambient light is the soft, general illumination that fills the volume of a room with a glow of light, and softens the shadows on people’s faces. It is the most important of the four functions of light, but is often the one element that is left out of the design of a room or space.
The best ambient light comes from sources that bounce illumination off the ceiling and walls. Such light fixtures as opaque wall sconces, torches, indirect pendants and cove lighting can provide a subtle general illumination without drawing attention to the light source. You could call is the open-hearth effect, where the room seems to be filled with the light of a glowing fire.
Just filling a room with table lamps is not an adequate source of illumination. The space winds up looking like a lamp shade showroom. Let these lamps be a decorative source, creating little islands of light. Using opaque shades and perforated metal lids, as was mentioned earlier, can turn these fixtures into more effective reading lights (task lights) if that is their main purpose.
Utilizing other sources to provide the necessary ambient light lets the decorative fixtures create the illusion of illuminating the room, without dominating the design. This inclusion of an ambient light source works only if the ceiling is light in color. A rich plum colored ceiling in a Victorian-style dining room or a dark wooden ceiling in a cabin retreat would make indirect light sources ineffective, because the dark surfaces absorb light instead of reflecting it.
In situations such as these the solution may be to lighten the color of the ceiling. Yes, what I am saying here is that sometimes the answer is to alter the environment rather than change the light source. Instead of the whole ceiling being eggplant-colored, how about painting a wide border in that color with the rest of the ceiling done in a cream color or similar hue? A wooden ceiling could be washed with an opaque stain that gives it a more weathered look without taking away from the wood feel itself, as simple painting would do. In both cases, using a chandelier or pendant fixture with a hidden indirect source could provide the much needed ambient light while maintaining a traditional look.
Ambient light, too, just like the other three functions, should not be used by itself. What you end up with is the cloudy day effect, where everything is of the same value, without depth or dimension. Ambient light alone is a flat light. It is only one component of well-designed lighting.
Light layering, the bottom line
A lighting design is succecssful when these four functions of light are layered within a room to create a fully usable, adaptive space. Good lighting does not draw attention to itself, but to the other design aspects of the environment. An entryway, for example, desperately needs ambient and accent light, but may not need any task light, because no work is going to be done in the entry. However, there may be a coat closet, which would need some task-oriented illumination. The addition of a ceiling mounted decorative fixture helps set the tone for the rest of the house.
What we often see in various design magazines is a house lighted for entertaining only. It is a very dramatic, glitzy look. Every vase, painting, sculpture and ashtray glistens in its own pool of illumination. Yet, the seating area remains in darkness. What are these people going to do for light when they want to go through the mail, do their taxes, or put a puzzle together with their kids?
In reality, people entertain only part of the time. The rest of the time these rooms are used to do homework, clean, and interact with other family members or guests. This doesn’t mean that you should eliminate accent lighting. Just don’t make it the only option. Simply putting ambient light on one dimmer and accent lighting on another provides a whole range of illumination level settings. Don’t forget to add a layer of task light and decorative light to the mix as well.
If once the installation is done and someone walks in and says, “Oh, you put in track lighting, it means that hte lighting system itself is the first thing seen which kind of defeats the purpose. If they walk in and say, “You look great!” or “Is that a new painting?” then you know the lighting is successfully integrated into the overall room design and that you have done a good job.
photo: Dennis Anderson
This family room uses a pendant fixture by Lightspann to offer both decorative and ambient light, while recessed adjustable low voltage fixtures by Lucifer Lighting add a layer of accent lighting.
photo: Dennis Anderson
This beautiful alabaster pendant by JH Lighting draws people to the table while adding a wonderful glow of flattering indirect lighting. Recessed low voltage fixtures by Lucifer lighting add a visual punch to the art.
photo: Dennis Anderson
Pendant fixtures by Lightspann help create a more human scale for this living room. Low voltage tracks, mounted along the apex beam, create the much needed accent lighting.
photo: Dennis Anderson
A series of four fluorescent pendants by Flos give both fill lighting and a decorative element to this kitchen. Warm colored fluorescent puck lights by Tresco International provide task lighting along the countertops.
photo: Dennis Anderson
Subtle lighting from above creates a dappled pattern of light and shadow for this intimate garden.
Randall Whitehead has written seven books on the subject of lighting design. His latest book is Residential Lighting, A Guide to Beautiful and Sustainable Design. All of Randall’s books can be ordered at Book Masters by calling 800.247.6553 or via email firstname.lastname@example.org. Samples of his work, books, and video clips can be seen on his website www.randallwhitehead.com.
I have to say it’s an exciting time to be practicing architecture. Yes the economy has put all sorts of new pressures on us and challenges in our path. But the mainstreaming of environmental considerations is delivering architects much more enlightened clients and an abundance of new products, materials and strategies that will allow us to create bold new designs.
The early years of the green architecture movement largely produced buildings that single-mindedly wrestled with the technical issues of energy and resource conservation while neglecting larger design issues. As a result sustainable architecture gained a reputation as being clunky and funky. This led the next generation of designers and builders to try to hide their efforts, often placing solar panels or water catchment systems behind screening elements.
There is now emerging a new wave of green design that is treating the unique materials, systems and strategies of sustainable building as opportunities that can generate new and exciting forms. It took architects a while to figure out that steel from the industrial revolution would allow them to break from classic proportions of masonry columns and beams, and that steel could lead to magnificent new forms. Today we are we beginning to see new structures that embrace and express our new building blocks. Let’s look at the beauty of what is possible when we choose to celebrate rather than hide our green.
Renzo Piano’s California Accadamy of Sciences integrates photo-voltaic panels to form an energy-harvesting sunshade.
Glenn Murcutt uses water-harvesting tanks as bold forms to compliment the pure geometries of his buildings.
This stunning Vertical Park by Jorge Hernandez de la Garza intends to infuse the city with much-needed green space in the form of a modular skyscraper made up of a series of stacking units. The solar-powered structure contains sky-gardens in addition to spaces for living and working, and recycles all of its own water.
Michael Jantzen’s Sun Rays Pavilion, consists of 12 massive columns that rise out of the earth like giant crystals reaching for the sun. Appropriate, because the acutely slanted building relies on the sun’s rays alone for power.
Designed in the shape of a drop of water, the Water Building Resort intends to become the first building ever to convert air into water with the help of solar power. It’s south facing facade made of photovoltaic glass will harness solar energy, allowing light to pass through. The northern facade features a latticed design for ventilation as well as Teex Micron equipment that will convert humid air and condensation into pure drinking water.
This new school of art, design, and media at Nanyang Technological University takes advantage of advanced green room technologies to add much needed structure while preserving scarce open space.
Vicent Callebaut’s Lilypad is a true amphibian – half aquatic and half terrestrial city – able to accommodate 50,000 inhabitants and inviting the biodiversity to develop its fauna and flora around a central lagoon of soft water collecting and purifying the rain waters. This artificial lagoon is entirely immersed, ballasting the city. It enables inhabitants to live in the heart of the sub aquatic depths.
Jonathan Feldman is the Editorial Director of Green Architecture Notes as well as the Principal of Feldman Architecture.
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.
Our friend at Baskervill in Richmond, Virginia offered us some insights into how green design strategies can be applied to a large commercial distribution facility to yield tangible savings. They were able to achieve 5-year pay-back for all of the green design investment incorporated, while making it possible for the client to realize an additional tax rebate to further justify the up-front investments. This case study is just another example of how all architecture should be green architecture.
The Trivett Distribution Center is a 300,000 square foot warehouse that Baskervill designed to capture all of the tax credits available through the Energy Policy Act of 2005. The distribution center achieved 57 percent more energy efficiency than the baseline energy standards.
The Energy Policy Act of 2005 (EPAct 2005) was enacted to provide a new federal tax deduction for expenses incurred for new and renovated energy-efficient commercial buildings. The maximum deduction for the whole building is equal to $1.80 per square foot, with partial deductions available. Applicants must acquire the blueprint for energy tax incentives from their qualified tax professional. The EPAct 2005 includes incentives for building owners as well as the lessee.
The improvements must reduce the energy and power operational costs by a minimum of 16 2/3 percent over the baseline energy standard as outlined in the ASHRAE 90.1-2001 requirements, the code minimum at the time the act was established. A qualified engineer is required to prepare an energy model using certified software as approved by te Department of Energy.
The maximum deduction is reached by achieving 50 percent over the baseline energy standard, which allows full credit of $0.60 per square foot for each of the three separate building systems:
- Interior lighting system
- Heating, cooling, ventilation, and hot water systems
- Building envelope
Some of the strategies employed include:
- Automatic lighting controls, occupant sensors, photocells, timeclocks
- Semi-conditioned space – heating and air conditioning with reduced thermal comfort standards
- Improved fan efficiency, reductions in static pressure
Currently EPAct 2005 tax deductions have been extended until 2013. The calculated payback for Trivett is under five years without factoring in the tax deduction. Due to the overwhelming success of this project, our industrial team attempts to achieve some level of EPAct benchmarks in all of our distribution centers as a standard of practice. Having the incentives in place gives our clients the financial benefits for having done so.
Water-proof Membrane (No vapor barriers required): Continuous on all six sides of building either above or below continuous insulation.
Lighting: Use only dimmable fluorescent (T-5) with 10% dimming electronic ballasts controlled by sensors to use available day light. Use recommended minimum IESNA foot candle levels for the specific visual task. Automatic occupancy sensors to turn off lighting when occupant leaves a space, and solar sensing blinds to prevent direct sun into the occupied space.
Glass: Exceed Energy Code minimums for performance. All glass on North & South exposures with South facing glass using external sun shades. No glass on East or West exposures.
Building Automation Systems: Controlling occupied/unoccupied times of day to optimize lighting, temperatures, security, fire detection and alarm systems.
Insulation: Exceed Energy Code minimums with continuous board insulation type (foam, rigid or fiberglass) for all six sides of building (foam only below lowest floor slab).
Energy Model – Computer software used to calculate energy, power consumption and costs must be approved by the Department of Energy
Heat Recovery Device – Building exhaust air used to pre-heat incoming ventilation air-Total Energy Wheel is best.
Smaller HVAC Loads – Smaller units = less weight on building = smaller footings and structural elements
57% energy use reduction
65% less energy for lighting
25% less energy for air intake
50% high efficacy in mechanical system fans
14% higher mechanical system combustion efficiency
50% higher efficient windows
47% less solar heat gain
16X more efficient warehouse roll-up doors
13X more efficient partitions separating offices and warehouse space
4.7X better insulation value in building envelope
3.3X better insulation value in the office envelope
Baskervill Environmental and Energy Practices (BEEP) is an internal resource aimed at educating clients on design that will benefit the environment, as well as maximizing the financial incentives available. Baskervill boasts 26 BEEP team members, over 20 LEED APs, and has currently completed eight LEED certified projects with two more underway.