The Abigail: Green Building
The Abigail made sustainable design and construction practices a priority early on by pursuing the US Green Building Council’s LEED© for Homes Rating System. The Abigail was designed, engineered and constructed with careful attention to its environmental impact, with a focus on reducing the use of energy and natural resources in the ongoing operation of the building. Below are some of the development’s sustainable and energy-efficient features:
 
Siting and Transit
The Abigail is located on a former rail yard and brownfield site at the north end of Portland’s Pearl District, a pedestrian- and transit-friendly neighborhood. It is four blocks from a streetcar station and within walking distance of multiple bus stops, a grocery store, restaurants, a school, parks and other urban amenities. To facilitate residents’ bicycle use, bike racks are located throughout the property, which also features a bike mechanic station. In the underground garage, preferred parking spaces are available for low-emitting, fuel-efficient vehicles.
 
Air Tightness

• The Abigail used a draft-free construction system to increase comfort, energy-efficiency, and indoor air quality.
• 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 air leakage, saving up to 20% of energy needed to heat and cool the hallways

 
Air Quality

• Low- or zero-VOC paint, carpet and sealants to reduce off-gassing.
• In the apartments, continuous ventilation fans exhaust 30 cubic feet per minute at all times. The make-up air for this exhaust fan is ducted to each apartment. This system provides conditioned air to the apartments so that residents do not have extra utility costs.
• Bathroom fans are connected to motion sensors to increase ventilation when in use.
• The hallway air supply is made up of 100% fresh outside air. There is no return air system so no air that is exhausted from the building is ever pumped back into the hallways.
• The Abigail is a non-smoking property: smoking is not allowed in apartments, on balconies or patios, in the garage or in common areas.

 
Insulation

• R-23 batt 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 reducing the use of lumber.
• R-30 rigid insulation at roof mounted on top of trusses to reduce heat loss through framing.
• R-15 batt insulation in ceilings and interior walls reduces heat transfer to adjacent apartments.

 
Apartment Heating and Ventilation

• Zonal heating systems allow residents to control how much of the apartment they heat.
• Electronic thermostats increase the efficiency of the heating system.
• All bedrooms have ceiling fans for ventilation.
• In most 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.

 
Common area HVAC

• High-efficiency heating and cooling equipment for common areas reduces energy use.
• Common-area HVAC has programmable thermostats with setbacks for off-peak periods.
• The leasing office and other separate common spaces use high-efficiency compact variable refrigerant flow HVAC equipment instead of conventional electric fan coil units to reduce energy use.
• The tighter building envelope allowed HVAC engineers to design for less leakage and to reduce the amount of energy used for heating and cooling by approximately 10%.
• 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.

 
Lighting

• Non-emergency fixtures are controlled by occupancy sensors. Light levels in hallways drop to lower levels during late night and early morning hours.
• 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 the room is in use
• The corridors include areas of large windows that reduce the need for artificial lighting.
• Light fixtures in the apartments are supplied with compact fluorescent lamps (in a warm light color) to reduce residents’ electricity bills.

 
Appliances

• Laundry rooms have energy-efficient gas dryers.
• Within the apartments, all refrigerators, dishwashers and washing machines are Energy Star rated (note: studio apartments do not have dishwashers and only the 6th floor apartments have washing machines).

 
Low-Energy Traction Elevators

• 50% reduction in electricity usage by installing traction elevators in place of conventional hydraulic elevators.

 
Water

• Central gas-fired hot water heaters are more efficient than individual electric hot water heaters.
• The apartments use high quality, water-conserving fixtures including 1.5 gallon per minute (gpm) showerheads, 1.5 gpm aerators on kitchen faucets, .5 gpm aerators on bathroom faucets and 1.28 gallon per flush (gpf) toilets.
• The courtyard uses native plants and has an efficient irrigation (drip systems, rain sensors) to reduce outdoor water use. Large planters contain layers of soil and gravel that are designed to retain, absorb and filter stormwater.