Green Building

Green Building

The Sitka was designed, engineered, and constructed with careful attention to its environmental impact. The building is maintained with the same focus and commitment by using nontoxic cleaning products and nontoxic landscaping practices.

The major focus of the environmental design was to reduce the use of energy and natural resources in the ongoing operation of the building. 

  • We started by engineering a very efficient building “envelope” (the walls, windows, and roof) to minimize the amount of heating needed.
  • We installed extra insulation to reduce heat loss and commercial-strength windows that eliminate drafts.
  • Most of all, we paid extraordinary attention to eliminating air infiltration through the walls. When we eliminate air infiltration through the outside walls, residents have fewer drafts in their apartments and lose less of their heat to air leaks.
  • Then we specified high-efficiency equipment so that our heating and lighting uses fewer natural resources.  The building and apartments have high-efficiency appliances, high-efficiency heating, cooling, and hot water heating equipment, and high-quality water-conserving plumbing fixtures and irrigation. 

There are many other ways we tried to reduce the environmental impact.  Here are some of the other eco-friendly features of the Sitka.

Low-Energy Traction Elevators

  • 50% reduction in electricity usage by installing traction elevators in place of conventional hydraulic elevators. (They move faster, too. Not an environmental feature, but nice for residents.)

Lighting

  • Garage lighting is more energy-efficient than the energy code
  • Hallway lighting saves energy in  three ways:
    • Uses all compact fluorescent fixtures
    • Fixtures are located for even lighting levels so that minimum wattage is needed
    • Non-emergency fixtures are controlled by occupancy sensors.  Light levels in hallways drop to lower levels when the halls are empty and come back to full lighting levels whenever someone is in the hall.
  • Other common rooms (baths, laundry, trash, bikes rooms, storage, etc.) and leasing offices are controlled by occupancy sensors so that lights are on only when room is in use
  • Light fixtures in kitchens and bathrooms of apartments are supplied with compact fluorescent lamps (in a warm light color) to reduce tenants’ electricity bills.

Appliances

  • Common Laundry Rooms
    • Front-loading Energy-Star rated washers in common laundry rooms
    • Gas dryers instead of electric in common laundry rooms
  • Apartments
    • All refrigerators, dishwashers, and washing machines are Energy-Star rated (note: only 1 and 2 bedroom apartments have dishwashers and only 12 ground floor apartments have washing machines).

Insulation

  • R-21 batts insulation in exterior walls (11% higher than code) for better apartment insulation
  • “Advanced framing” techniques - including studs at 24” on center – increase the insulating performance of the walls (and reduce the use of lumber)
  • R-32 rigid insulation (5% higher than code) at roof is mounted on top of trusses to reduce heat loss through the framing and to reduce drafts caused by ventilated ceiling cavities.
  • R-15 batt insulation in ceilings and interior walls reduces heat transfer to adjacent apartments.

Air Tightness

  • The Sitka uses an unusually draft-free construction system to increase comfort, energy-efficiency, and indoor air quality.  (A testing agency conducted a “blower door test” near the end of construction on about 20 apartments and found that they were about 2 to 3 times more air-tight than apartments in other wood-frame construction apartments.)
    • All joints and fasteners on exterior sheathing are caulked or covered in a self-adhesive membrane to prevent air infiltration into the building and to minimize heat loss through the walls.
    • The exterior walls are wrapped in commercial Tyvek to add an additional layer of protection against air and moisture infiltration.
    • All door and window openings are double-caulked and wrapped with self-adhesive membrane.
    • Windows are commercially-rated for strength and have low infiltration ratings
    • As noted above, rigid insulation on top of roof framing (instead of fiberglass batts laid between the trusses) helps to maintain the building’s air-tightness.  By eliminating the need for attic ventilation, this also reduces heat loss into the attic through light fixtures and other ceiling penetrations.
    • Shafts for heating and exhaust air are lined with sheet metal to reduce future air leakage, saving up to 20% of energy needed to heat and cool the hallways

Hot Water System

  • The Sitka uses central gas-fired hot water heaters rather than less expensive but inefficient individual electric hot water heaters
  • Hot water heaters are 98% efficient
  • Energy Star dishwashers in the apartments reduce hot water use
  • High-quality low-flow showerheads (2.0 gpm) and faucet aerators (1.5 gpm)  are both more efficient than code and help reduce hot water use
  • Apartments have submeters for hot and cold water. Residents who conserve water will get the financial benefits of doing so.

Heating, Ventilation, and Air-conditioning (HVAC)

     Common area HVAC

  • High-efficiency heating and cooling equipment for common areas reduces energy use.
  • Common-area HVAC equipment has “economizers” that switch to outside air for heating and cooling when temperatures permit doing so.
  • Common-area HVAC has programmable thermostats with setbacks for off-peak periods.
  • The laundry rooms have a separate heating and cooling system (rather than being heated and cooled by the hallway system).  The dryers have a circuit sensor system that allows the system to operate at lower volume when the dryers are not in use.
  • The leasing office and other separate common spaces use high-efficiency heat pumps instead of conventional electric fan coil units to reduce energy use.
  • The work done to make a tighter building envelope allowed the HVAC engineers to design for less leakage and to reduce the amount of energy used for heating and cooling by approximately 10%.
  • The hallways are slightly pressurized (more air being mechanically supplied than is being mechanically exhausted) so that the apartment exhaust fans do not pull outside air in through windows, electrical outlets, and other penetrations. 
  • The parking garage uses natural ventilation as much as possible.  This is supplemented by exhaust fans that are controlled by carbon monoxide sensors and operate only when needed – providing fresh air in the garage while conserving energy.

Apartment Heating and Ventilation

  • The apartments’ zonal heating systems allow residents to control how much of the apartment they heat.
  • The apartments have electronic thermostats to increase the efficiency of the heating system.
  • All bedrooms and living rooms have ceiling fans for ventilation.
  • The apartments’ large casement windows open all the way to the ceiling to improve ventilation.
  • The casement windows generally open to face the prevailing summer breezes.
  • High quality low-e coating on windows reduces summer heat gain and winter heat loss.

Air Quality

  • The apartments use low-VOC or zero-VOC paint, carpet, sealants to reduce off-gassing.
  • The apartments’ continuous ventilation fan exhausts 30 cubic feet per minute (CFM) at all times. The make-up air for this exhaust fan is supplied by the hallway heating and cooling system. This system provides conditioned air to the apartments so that residents do not have extra utility costs.
  • The hallway air supply is made up of 100% fresh outside air. There is no return air system so none of the air that is exhausted from the building is ever pumped back into the hall.
  • The Sitka is a non-smoking property – smoking is not allowed in apartment, on balconies or patio, in the garage, or in common areas. 

Water Use

  • Water submeters encourage (and reward) conservation by residents.
  • The Sitka uses water-conserving fixtures in the apartments - 2.0 gallon per minute (gpm) showerheads, 1.5 gpm aerators on faucets, and 1.6 gallon per flush (gpf) toilets. 
  • The courtyard uses only native plants and has an efficient irrigation (drip systems, rain sensors) to reduce outdoor water use.

Materials

  • Structural systems use manufactured wood beams when possible to conserve lumber.  Studs are placed at 24” spacing when possible.  Though this requires larger studs (e.g. 2x6 instead of 2x4), it results in less overall lumber use.  We also use finishes such as MDF trim (a manufactured product) and wire shelving when possible to minimize lumber use.
  • Building uses recycled content sheetrock and insulation.
  • Structural concrete uses maximum feasible fly ash content.