Smooth Operator
Credit: Mariko Reed
It’s hard to believe a 4,600-square-foot house with 80 windows and doors could be green, much less LEED Platinum certified, with efficiencies that beat California’s Title 24 energy standards by 55 percent. But this Oakland, Calif., residence has it all.
Before construction, the window plan was put to the test in a modeling program that calculated the impact (based on placement) of operable versus non-operable windows, explains builder Mike McDonald. “We were able to eliminate a lot of superfluous operable features that didn’t contribute to cross-ventilation. This helped from a cost perspective, achieved a lower U value overall, and improved aesthetics. A lot of the windows we’d originally planned as operable didn’t look as nice as fixed glazing.”
The strategic window schedule combines thermally broken aluminum windows by AlumaTherm—a third of which are operable—with a NanaWall retractable wall system. Deep eaves and a dramatically cantilevered awning accentuate the window arrays while protecting interior spaces from the hot summer sun. Other green features include: an Energy Star cool roof; a 600-square-foot “living roof” and deck; LED lighting; in-floor hydronic heating; solar electric power and thermal hot water; smart-home automation; energy-efficient appliances; on-site water reclamation tanks; permeable paving; concrete countertops made with fly ash and recycled glass; indoor air quality management system; drought-tolerant landscaping; zero-VOC paints; and locally sourced, sustainable products such as metal tiles made from discarded kiln shelves.
Project: Margarido House, Oakland, Calif.;
Builder: McDonald Construction and Development, Oakland, Calif.;
Architect: Plumbob Architects, Philadelphia;
Windows: Alumatherm and NanaWall Systems
Nice Slice
Credit: Stefan Hampden
Townhome “four packs” are a common infill solution in Seattle. This time around, CAST Architecture made the most of a split-zoned lot (a small sliver of which was designated commercial) by squeezing in an extra live/work space for a total of five units. But it wasn’t easy, considering the commercial slice was only 10 feet wide. To create a feeling of spaciousness in the skinny unit, the architects vaulted the living room ceiling to 12 feet and glazed the entire end wall with a grid of low-E, thermally broken aluminum frame windows by Marlin, some of which are operable. This move facilitated natural daylighting and cross ventilation, contributing to a Built Green four-star rating.
“Thermally broken frames don’t sweat when it gets chilly out, so moisture isn’t a problem,” notes architect Stefan Hampden. “Aluminum is also beneficial in that it can be recycled over and over again. And these windows have a clear anodized finish so they never have to be painted.”
All that—and it looks cool. Advanced framing with rim joists contributed to the window wall’s sleek façade by eliminating the need for headers. “The nice thing about these windows is that instead of mulling units together to create groupings, the manufacturer built the whole thing up at once,” Hampden adds. “That way you don’t have the thickness of an extra flange in there, and you end up with a thinner profile.”
Other green features include: high-efficiency boilers for radiant heat and hot water; R-26 wall and R-50 roof spray-in insulation; electric-vehicle charging stations; rain screen siding; and bamboo flooring pre-piped for solar hot water.
Project: Fremont Townhomes, Seattle;
Builder: Albion Group, Seattle;
Architect: CAST Architecture, Seattle;
Windows: Marlin Windows
Glass Menagerie
Credit: Chris Hodney
This 16-story, mixed-use tower in Portland, Ore.’s Pearl District takes the form of a basic box, but within that box are some poetic variations. Exterior architect John Holmes with Holst Architecture fashioned the window schedule to resemble the fractal patterns found in natural rock formations. The stacked bricks comprising the solid portion of the façade adhere to uniform specifications (each vertical pier between windows measures 2 feet, as does each horizontal band between floors). But the window sizes are sporadic, with openings varying in width increments of 5, 7, or 9 feet. The brick shell forms a lattice for a commercial-grade extruded aluminum window system by local manufacturer Custom Window Co., explains co-developer Geoff Wenker. “We also randomized the operable parts, so no two units are exactly the same.”
The building’s east-west orientation was unavoidable given site constraints, but a heat recovery ventilation system helps even out the effects of solar gain. “When the sun is hitting the south side of the building, those units might be in cooling mode, while the north-facing units are in heating mode on the same day,” Wenker says. “The heat source pump captures heat from the south units and transfers it to the north side. The main boiler never has to come on.”
That’s just one of many features allowing this LEED Platinum-certified building to use 30 percent less energy and water than similar post-tension concrete structures. Other green features include: a green roof with 4,000 square feet of vegetation and planters for stormwater filtration; externally vented kitchens; dual-flush toilets; bicycle storage; electric car charging stations; and proximity to public transit. In addition, 90 percent of construction debris was recycled.
Project: 937 Condominiums, Portland, Ore.;
Builder: Andersen Construction, Portland;
Architects: Ankrom Moisan Associated Architects, Portland; and Holst Architecture, Portland;
Windows: Custom Window Co.
Fine-Tuned
Credit: Dan O'Connor
The budget for this green makeover of a 1960s tri-level home was rather modest, so VaST architecture left the footprint alone and didn’t change much in the way of façade composition. Most of the original window openings were kept intact, although the team swapped out the home’s drafty old glazing and replaced it with an insulated, fiberglass-framed product by Serious Materials with high-performance tinted glazing to control heat gain.
“The performance upside of fiberglass is that it expands and contracts at the same rate as the glazing,” explains VaST studio manager and designer Brandy LeMae. This reduces internal stresses and makes the entire window system and weatherstripping more airtight. “This is a big deal in a climate with big temperature swings,” LeMae adds.
Credit: Courtesy Vast
Another advantage? “Serious Materials allows you to ‘tune’ the tinted glazing on your windows and adjust the heat gain coefficient depending on which direction they are facing,” says LeMae, noting that the specs for this home included two different coefficients. The remodel also included a new kitchen and a reconfiguration of select interior spaces. Other green features include: Icynene insulation; high-efficiency CFL lighting; and a heat recovery ventilation system.
Project: Olsen Residence, Boulder, Colo.;
Builder: RandomSPACE, Boulder;
Architect: VaST architecture, Boulder;
Windows: Serious Materials
Sealed Deal
Credit: Jamie Broadbent
This 2,500-square-foot house is in Falmouth, Maine, where winter temperatures routinely plunge into the 20s. And it doesn’t have a furnace.
This feat was made possible, in part, with an airtight double shell, extra insulation, a thermal concrete slab, and triple-glazed Thermotech fiberglass fixed and casement windows. Large, operable windows on the third story allow hot air to circulate up and vent out in summertime, and south-facing windows are capped with deep overhangs for shade protection.
Builder Dan Kolbert and architect Phil Kaplan estimate the triple-glazed windows cost as much as 50 percent more than comparable double-glazed units, but say this worthy investment will likely bolster the energy performance of this blow-tested and soon to be LEED Platinum-certified house by an extra 20 percent. “We design with an actual budget as well as an energy budget in mind,” says Kaplan. “If we want to keep the mechanical system small and make it a truly low-energy house, we can only afford so many square inches of glass. If the walls are R40 and the roof is R60 and your typical double-pane windows are around R3, you are creating a huge energy leak in your house. Using triple-paned windows made a big difference here (they have R values up to 6.25) but we also had to be strategic about where we put them.”
Other green features include: roof-mounted photovoltaics for solar electric and hot water; electric on-demand heater for winter; energy recovery ventilator; and low-flow plumbing fixtures.
Project: Double Thick Walls on the Dime, Falmouth, Maine;
Builder: Dan Kolbert Building & Renovations, Portland, Maine;
Architect: Kaplan Thompson Architects, Portland;
Windows: Thermotech Fiberglass Fenestration
Suite Success
Credit: Rick Hammer
Energy Star–rated windows by Marvin play a leading role in this 3,600-square-foot lakeside, Arts and Crafts–style home, the first LEED-certified residence in the state of Minnesota. “We made a concerted effort to go green, but because this was a spec home, it also had to be financially feasible,” says builder Ed Northway.
To keep costs in check, Northway assembled four Ultimate Double Hung windows (two are mulled together) and four transoms in a dramatic pattern to frame the view of the adjacent lake. Simulated divided lites with spacer bars give the pine-clad windows a classic old school look, while low-E glass coatings enhance energy efficiency. An exterior bronze finish complements the home’s natural cedar siding.
Other green features include: spray foam insulation; ICF foundation; a tankless water heater; paperless drywall below grade (to prevent mold); a high-performance HVAC system; foundation drainage; Energy Star–rated appliances; old-growth tree preservation; and native landscaping.
Project: Gull Lake Home, Brainerd, Minn.;
Builder: Northway Construction, Baxter, Minn.;
Architect: Kevin Yeager, Brainerd;
Windows: Marvin Windows and Doors