11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS LOT SIZE: 6,000 sf BUILDING SIZE: 14,900 sf | 20 Units LOCATION: Seattle, WA PROJECT TYPE: Multifamily Apartments (Conceptual)
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 1
TOWARD BUILDING AS CLIMATE ACTION A Net Zero Showcase in Multifamily Building This multifamily Passive House project responds to pressing questions facing our city: How to provide housing that is affordable to Seattleites being priced out of the market? How to create new architecture while honoring the built legacy of our neighborhoods? How to create buildings that help Seattle achieve its Climate Action Plan, rather than hinder it? The intent of 11th & Republican is to provide a model response to these questions, demonstrating the value of high performance multifamily buildings to the city and its neighborhoods. The building’s design celebrates both its Passive House building energy conservation (by expressing its generous envelope thickness and passive solar shading) as well as its onsite renewable energy generation (by visibly showcasing its rooftop array in harmony with the building’s primary volume). The project preserves a historic home, retrofits it to the ambitious Passive House standard, and melds it with a new four-story Passive House structure. The combined twenty residential unit building will become one of Seattle’s first market-rate multifamily apartment buildings to achieve Passive House certification, and represents an important R&D project – one that the
project team will document and share thoroughly. The project’s rooftop array, in addition to enabling the building to reach for Net Zero Energy status, will serve as a visible reminder to passersby of the efficacy of onsite renewable energy to power buildings. The design takes the existing home, relocates it to the SW corner of the site, adds an addition, and then positions a new building across a small courtyard space. An elevated solar PV array using special diaphanous panels connects the old structure with the new while providing the onsite renewable energy necessary to become a Net Zero Energy Building. The new building mirrors the existing house in proportion and massing. The open space between the two buildings, spanned by tiers of exterior walkways, facilitates natural ventilation and daylighting in each unit. A mix of unit types provides housing for a mix of income levels and household size. Below grade units (with access to daylight and ventilation) and studio apartments provide the most affordable units, while 3-bedroom and 2-bedroom units can house families. The focus: preserve the existing house, preserve the scale of the neighborhood, and create a multifamily building that helps preserve our climate future.
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 2
PASSIVE HOUSE APPROACH
AIR TIGHTNESS
PHOTOVOLTAIC SOLAR PRODUCTION
INSULATION
HEAT RECOVERY VENTILATION (HRV)
SEASONAL SHADING
HIGH PERFORMANCE
BENEFITS
WINDOWS
DURABILITY / enhanced wall assembly protects building structure HIGH PERFORMANCE / reduces energy demand COMFORT & HEALTH / fresh air and consistent temperature year round
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 3
GETTING TO NET ZERO ENERGY | reduce + produce Passive House + Solar = Net Zero Energy
Passive Ventilation
Estimated energy budget for a net zero ready residential building = 18 EUI. At this EUI, 1 sf of production area powers about 4 sf of floor area.
Natural ventilation provides fresh air and eliminates need for air conditioning.
1SF PV
1SF
4 3
18 EUI 18 EUI
1SF 1SF
2 18 EUI
1SF
1
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 4
DESIGN STRATEGIES
CONTINUOUS MINERAL WOOL BLANKET TO ELIMINATE THERMAL BRIDGING STANDING-SEAM METAL ROOF OVER CONTINUOUS RIGID INSULATION NEW CONSTRUCTION: STAINED CEDAR SIDING, R = 27.8
REUSE EXISTING HOUSE ADDITION KEEPS TRADITIONAL LANGUAGE OF EXISTING HOUSE
BELOW-GRADE PARKING REPLACE EXISTING WINDOWS WITH HIGH PERFORMANCE, TRIPLE PANE WINDOWS WITH AN OVER-INSULATED FRAME
RETROFIT WALL: CHAMFERED WOOD TONGUE & GROOVE SIDING, R = 27.8
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 5
DESIGN STRATEGIES
EXTERIOR SHADES
CONTINUOUS INSULATION ON ROOF PASSIVE SOLAR
LARGE BALCONIES
SOLAR PANELS
CROSS VENTILATION THROUGH UNITS
VIEWS TO BROADWAY HILL PARK
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 6
RENDERING one | SW Corner
The western façade overlooks the Broadway Hill Park, providing “eyes on the park.” Balconies provide shade for western-facing units. 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 7
RENDERING two | SOUTH Façade
Old and new buildings connected by light-colored, diaphanous solar panels. Central courtyard provides amenity space for residents. 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 8
RENDERING three | SE Corner
The existing building is shown here, with addition to the right. Detailing for historic house is updated and simplified for Passive House envelope design. 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 9
RENDERING four | NE Corner
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 10
EXISTING BUILDING
Existing house is a typical example of original houses in neighborhood. 1950s-era additions will be removed and the house will be retrofitted as a Passive House. 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 11
SITE PLAN
NEW ADDITION
BROADWAY HILL PARK
NEW BUILDING RELOCATED EXISTING BUILDING
RAMP TO PARKING LEVEL
T.O. STAIR
11TH AVENUE E
EXISTING 2-STORY HOUSE
DN VEHICLE ENTRY PEDESTRIAN ENTRY
E REPUBLICAN STREET The new building (left) mirrors the existing building/ addition in width and massing. Pedestrian entrance is from the center. Private patios overlook park (left). 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 12
366
2
STEPPING STONES
365
36
364
363
36
LANDSCAPE PLAN LANDSCAPE PLAN EXIST. POLE LIGHT TO REMAIN
+ 365'
SS
STONE PRIVATE PATIO, PEDESTAL PAVERS, TYP.
STONE SEAT STEPS
PA
LEVEL 2 + 371'
LIVE EDGE WOOD BENCH, TYP.
7
36
367
CONCRETE SLAB UNDER STAIRS
TJ
AMENITY AREA, PEDESTAL PAVERS, TYP.
LEVEL 1 + 361' PLANTER
PA
A
TJ
+ 361'
NEW STREET TREE, TYP.
PEDESTRIAN PASS THROUGH
MAIL BOXES SS
SD
LEVEL 1 + 361'
11TH AVENUE E
SD
OVERHEAD CANOPY
361' PA
+ 371' SD
TJ PA
PA
SS
W
W
TJ
SD
SS
TJ
TJ
PA
PA
TYPE A: A central courtyard provides amenity space for A PER COS STD PLAN 420 WITH THE FOLLOWING EXCEPTIONS: -SCORING TO MATCH AND ALIGN WITH EXISTING ADJACENT SIDEWALK residents. A generous right-of-way allows for extensive landscaping, enhancing the streetscape.
PEDESTAL PAVERS
| 0’
| 5’
| 10’
^ N
11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 13
FLOOR PLANS
BATH
BATH
BED
BED LIVING
LIVING BATH
KITCHEN
LIVING
BATH
KITCHEN
LIVING
KITCHEN
KITCHEN UP
UP
LIVING
LIVING KITCHEN
KITCHEN
BATH
KITCHEN
BATH
BED BED
BED
BATH
DN
BATH
BED
DN
BATH
LIVING LIVING
KITCHEN
BED
KITCHEN
KITCHEN
LIVING
LIVING BED
BED
BATH
BATH
LEVEL 2
LEVEL 4
BATH
BATH
KITCHEN
BED
BED
LIVING
LIVING KITCHEN
BATH
KITCHEN
LIVING
LIVING KITCHEN UP LIVING
LIVING KITCHEN
KITCHEN
BATH
KITCHEN
BATH BED
BED KITCHEN
BED
BATH
BATH
BED
DN
BATH
BATH KITCHEN
LIVING
KITCHEN
BED
LIVING
LIVING
BED
BED
BED
BATH
LEVEL 1
BED
LIVING
BATH
LEVEL 3
Diverse unit mix provides access for residents from a mix of income levels and household size. From studios and basement units to 2- and 3-bedroom units. 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 14
BUILDING SECTION
UNIT
UNIT
UNIT
UNIT
UNIT
ELEV
UNIT
SOLID WASTE STORAGE
UNIT
UNIT
PARKING
BIKE STORAGE
ELECTRICAL
The project adds a story under the existing house. Both buildings rest on concrete plinth created by underground parking and utility spaces. 11TH & REPUBLICAN PASSIVE HOUSE APARTMENTS | p. 15