LEDs as Task Lights



For me, using LEDs as task lighting is still a developing technology. I am very happy with the lumen output that we are starting to see now, along with the color quality. I personally lean towards a warmer color tone that is close to that of incandescent (2700° Kelvin), but many others do prefer the slightly cooler color temperature like that of halogen (3000° Kelvin). Still others that are doing fine detail work, such as jewelry making, like to have a color temperature close to that of daylight (5000° Kelvin).

Where I am seeing room for improvement is how to deal with the creation of multiple shadowing when more than one LED source is used in a task light. Those fixtures on the market with a single source LED act like a single source incandescent or fluorescent. One source equals one shadow, which is what we have all grown up with what we are used to seeing. But a single source LED may not provide enough illumination for many people. When multiple light sources are used, as we are seeing in the LED task lights that are coming onto the market, you get a shadow image for each light source. The more individual LED diodes you have in a fixture the more shadowing you get as well. When reading a book or a magazine this really isn’t an issue, but if your hand, pen or pencil comes in between the light source and the work surface it can have a lot of disconcerting shadowing with which to contend.

Although I am not lighting fixture designer, per se, I think of myself as an informed consumer who is constantly testing what is available out there on the market. My suggestion to the task light designers is that when multiple LED sources are used then some sort of diffusion material, in the form of a lens, will help ameliorate the problem. As individual LED sources become stronger and only one source is used then shadowing no longer is an issue.

Many manufacturers of recessed LED fixtures have seen that that this multiple shadowing was an issue and have produced fixtures with an integral diffusion lens. It would be a good idea if the manufacturers of LED task lights would take a look at what the recessed LED fixture manufacturers are doing and see how they can incorporate the addition of a diffusion material into their products.

I still am a very strong advocate of using LED sources for task lighting. I would just like to see the next step in refinement; so that when people make the investment they are getting something that they can live happily with for the next 16 or 17 years. Since LEDs last for so darn long I want to make sure that my love will last.

Randall Whitehead is a frequent contributor to Green Architecture Notes.

The Dirt on Airing Your Laundry

An easy way to save energy this summer is by foregoing your dryer and using a clothesline to air dry laundry.  In the heat of summer, I can’t bear to use my dryer, so I picked up a simple, retractable clothesline from my local hardware store.  I am surprised how much I enjoy using my clothesline!   There is something romantic about seeing a line of clothes fluttering in the wind.  And sun-dried sheets on a freshly made bed is heaven!  Of course, being a designer, I couldn’t help search for more design-y clothes-drying products.  – Lindsey

Here are my favorites:


Above Left:  The Alberto clothesline from Fabrica.  Each “tree” is about 6’ tall.
Center:  Vintage clothespins are so cool looking.  They are easy to find online too, this image is from a shop on Etsy.
Above Right: For those who don’t have the luxury of outdoor space for air-drying, uncommongoods offers an easy mount indoor clothesline.
Below Left: There are even cute ways to store clothespins.  You easily could make your own, but this one is from uncommongoods.com.
Below Right: I love this idea.  Start them young!


Greenways: Feldman and Clients Get Around Town

Most of Feldman Architecture’s clients appreciate the importance of sustainably built homes and ask us to help them make choices that use materials wisely and reduce energy use. We know that buildings consume almost half of all fossil fuels burned in the United States, but not surprisingly, transportation consumes the next largest percentage of fossil fuels.

The team here at Feldman Architecture does its part to reduce carbon emissions by making smart choices in the buildings we design and how we commute to work. With few exceptions we all regularly bike, walk, take public transportation, or ride a scooter to our offices in SOMA. One of us even recently started taking a ferry that runs on bio-diesel.  Since 50% of our office does not own a car, we visit job sites using City Car Share or Zip Car whenever possible.

We bring this same awareness of alternative transportation issues to our projects. Four projects under construction will offer dedicated 240 volt outlets with upgraded electrical panels for owners’ future electric cars. Several of our completed projects generate sufficient electricity through photo-voltaic panels to charge these vehicles. A project site in Santa Cruz was specifically chosen for its proximity to the beach, schools, transit and shopping. Though this particular client currently lives in Ohio, he has already bought a bike to avoid renting a car on his frequent site visits. For another project under construction, the owners will enter their home – frequently sweaty and muddy – directly through a large bike storage room. These clients have gotten creative with their bikes – see the photos below!

All of these efforts use energy wisely and conserve resources, but they’re also a great way to travel around the City and appreciate the sights.  –  Brett


Heron’s Head EcoCenter: Part 2 – Structural

The completed EcoCenter from the South East.

As a follow-up to a recent post on Heron’s Head EcoCenter, we caught up with Alex Rood of Fulcrum Structural Engineering to discuss his contributions to the project. For those who have not read our recent post on the project, Heron’s Head EcoCenter is San Francisco’s first off-the-grid educational facility and laboratory for sustainable design sponsored by the non-profit organization Literacy for Environmental Justice. A project 10-years in making, the EcoCenter was finally completed in 2010, and incorporates many innovative sustainable design features including solar panels (both PV and solar thermal), living roof, rainwater harvesting, greywater reuse, living machine on-site wastewater treatment, SIP panels, super green concrete mix, recycled building materials, passive design, and the list goes on.


Site/soil: Located on a former industrial landfill in Hunters Point neighborhood of San Francisco, Alex’s first challenge was to design the foundation system that could sit atop the soil with extremely poor bearing capacity. To overcome the less than favorable soil condition, he decided to utilize 10” mat slab but he also had to incorporate a series of troughs for the indoor constructed wetland into the slab/foundation design. The challenge did not end there. The soil condition was so poor that he was told to anticipate as much as 10” to 12” of settlement over time. This meant utilities that would typically be laid below the slab now had to be routed within concrete troughs formed into the slab until they exited the structure above grade to make service connections. To make matters worse, he found out that below the site is a clay layer of landfill cap designed to remediate the contaminated soil, but the exact depth of this cap layer could not be determined. He had to proceed with caution to ensure that the weight of the structure would not cause the cap layer to fracture. In addition to solving all of these engineering challenges, it was his job to provide a cost effective foundation design to fit the tight budget of the project.

Rebar prior to pouring of the concrete foundations.

Concrete: Almost every modern structure in the world uses concrete to varying extent. While its longevity makes it a good building material, the environmental footprint of cement production is something Alex wanted to tackle on this project. According to Alex, experts estimate that cement production contributes to about 7% of carbon dioxide emission from human source. He started by specifying a green concrete mix containing 50% slag for cement replacement but once the job broke ground, he collaborated with the concrete sub-contractor and the supplier, Bode Concrete, to push this green concrete mix further, ultimately ending up with 80% slag and 100% recycled course aggregate. In the end, not only was he able to use the greenest concrete mix he, or Bode Concrete, had ever heard of, but the builder was able to provide concrete that was superior to the original specification in many ways. It ended up exceeding the compressive strength requirement by two fold, the concrete showed no cracks and will provide superior protection against rebar corrosion, all thanks to its high slag content.

SIPs panels prior to sheathing

Framing: Once out of the ground, the remainder of the structure was designed using Structural Insulated Panels (SIP). Having worked on many other SIPs jobs with the project architect, Toby Long, Alex knew that Toby would want to use SIPs for the project for many of its environmental preferable attributes. There are always challenges in designing SIPs structures in seismically active zones, especially when the building is not a simple box but he was able to use his extensive experience with SIPs to help Toby realize his design. Being the first SIPs project for the builder and the framing crew, he worked very closely with the builder and was often asked to offer creative solutions to troubleshoot issues arising in the field. Thanks to the countless hours of research by the LEJ project manager Laurie Schoeman, SIPs panels made with FSC-certified OSB panels were sourced. All framing lumber used in the job to amend the SIPs system was also all FSC-certified.

We asked Alex what was the best part of the project for him.

The completed EcoCenter from the South East




It was the collaborative effort with the concrete sub-contractor, Gerald Creed of OSM Co. and the local concrete producer, Bill Garland of Bode Concrete. In fact, it was Gerald who initiated the idea of exploring an even greener concrete mix than the 50% cement replacement originally specified. Bill had worked with a concrete mix with 75% cement replacement, and he has also used crushed returned course concrete aggregate in non-structural flatworks. Not only did we decide to combine both of these ideas, but we also decided to use the mix for the structural slab/foundation, while increasing the slag content by additional 5%.

Alex believes it was the collective knowledge and will to do the right thing for the environment that allowed them to take the leap of faith to push the boundary of the green concrete mix. Everyone went above and beyond their call of duty to come up with the greenest concrete mix they have ever worked with.

Taisuke Ikegami is an architect working at Feldman Architecture and is a frequent contributor to Green Architecture Notes.

Notes from Designing Living Roofs – Part III

The roof garden from above with terrace.

In previous posts, we have looked at the addition of a green roof over a garage at a residence located on a steep slope which provided the clients with a planted space in the front of the house.  In a second post, we looked at the implementation of a green roof as a key design component which allows the new residence to blend into a lush landscape.

In this section, we will take a look at the design of a new residence which provides a garden hideaway for the clients.  For the 2 Bar Project in Menlo Park, California, the clients came to the project looking for cost effective, energy efficient solutions for their home. They are also avid gardeners and offering the clients additional square footage to plant, as opposed to a traditional roof, was appealing to the clients.

The 500sf roof garden is hidden from view until climbing the main stairway and catching a glimpse of the garden from the second floor bridge.  Accessible from the master bedroom,

View to the garden from the master bedroom.

the green roof includes a recessed roof deck which comfortably seats the family of four. In terms of sustainability, the green roof over the living/dining/kitchen area serves to insulate the house in cool weather, controls solar heat gain and reduces water run-off.

Typical, intensive green roof assembly would have required up-sizing of the roof framing, including additional steel, rendering it cost prohibitive. Instead, an exceptionally lightweight engineering with a shallow 2-6” soil depth for the 2 Bar green roof assembly with sedum plants and river rock edging overcomes this challenge. The garden, designed and planted by Lauren Schneider of Wonderland Garden, has been blooming for two years.  Sedum, succulents, aloe, vivums, and ice plants make up the garden which flowers in swaths of white and purple – an unexpected, secret garden in a suburban neighborhood.


View of house and green roof.

The green roof here includes a layer of plastic coating, a roofing barrier, a drainage mat to facilitate drainage, a capillary mat that holds water and encourages plants to take root, a subterranean drip system, a filter fabric to prevent the soil from clogging, a lightweight planting material (15 pounds per square foot) and the seedlings.

Jonathan Feldman is Editorial Director of Green Architecture Notes and Principal of Feldman Architecture.

Sustainable Sidebar: Surfaces “What Can’t You Recycle or Reuse?”

In this Sustainable Sidebar product post, we’ve decided to highlight a few sustainable surface materials durable enough to handle the daily wear-and-tear on your dwelling, but won’t harm your conscience. Made with recycled content, rapidly-renewable resources, natural composite materials, or all of the above, these products are healthy for you, your home, and the environment… Did I mention some of them are also playful and fun?!

ShektaStone – Counterfeit Line: Recycled Paper – Currency removed from Circulation

ShetkaStone is made from 100% recycled paper, plant, or cloth fibers. For the counterfeit line they use shredded currency, removed from circulation. Plaster, plastic polyester, and paper glue are used as supplemental binding agents, and then sealed with a zero VOC finish. When you’re finished with your ShektaStone, it can be recycled and used in the manufacturing of new products.

Teragren – Moso Bamboo: Strand Face in Wheat

Bamboo is an amazing material. Used for everything from serving utensils to structural building materials, this resource covers the gamut and it’s rapidly renewable. Teragren uses a specific species of bamboo for their surfaces. Optimum 5.5 Moso Bamboo from the Zhejiang province in China, is among the hardest species, with extremely dense fibers. Bamboo reaches maturity every 5-1/2 to 6 years, when it is then harvested for use.

ConcreteWorks – Color Husk: Concrete surface with Rice Hull Fillers

ConcreteWorks has developed a sustainable concrete without compromising its wonderful character. They have replaced raw aggregates with post-consumer recycled material and industrial by-products, diverting upwards of 80% of the total product weight in material from landfill. In the Husk color, one of those recycled fillers is rice hulls. This protective covering for a grain of rice, is a natural substitute for raw aggregates and creates beautiful visual texture.

Trinity Glass – Absolutely: Recycled Glass and Low-Carbon Cement

Trinity Glass is a composite surface made from a patent-pending formulation of recycled glass and low-carbon cement. The surfaces are used for countertops, tabletops, wall cladding, and exterior surfaces. The beautiful color palette is suitable for any design, commercial or residential.

OKITE – Prisma Giallo: Quartz

OKITE is composed of natural quartz crystals. This surfacing material is highly stain and scratch resistant, making it a great option for kitchen and bath applications. The manufacturing process creates a product that is harder, non-porous and easier to maintain than natural stone.

Squak Mountain Stone – Recycled Paper and Glass / Low-Carbon Cement / Fly Ash – Natural

Squak Mountain Stone is a fibrous-cement material comprised of recycled paper, recycled glass, coal fly-ash and cement. The material is hand-cast into “slabs” as an alternative to natural or quarried stone. This product is finished beautifully with a similar resemblance to soapstone or limestones.