TETHER

TETHER TIM SCHNEIDER M.Arch Thesis, University of Oregon ‘15 AIA COTE Top Ten for Students Competition, ‘15-’16

“To waste, to destroy our natural resources, to skin and exhaust the land instead of using it so as to increase its usefulness, will result in undermining, in the days of our children, the very prosperity which we ought by right to hand down to them amplified and developed.�

-Theodore Roosevelt

• Introduction

3

• Site

7

• Design Concept

9

• Design + Innovation

17

• Regional/Community Design

21

• Land Use + Site Ecology

23

• Bioclimatic Design

25

• Light + Air

29

• Water Cycle

33

• Energy Flows + Energy Future

37

• Materials + Construction

41

• Long Life, Loose Fit

45

• Collective Wisdom + Feedback Loops

47

A river is only a small part of a large, inter-connected natural system involving various ecological and hydrological functions. It is in a constant state of flux and of vulnerability. Careless human actions have had detrimental effects on the Mississippi River system. These effects, seemingly insignificant in their individuality, may not be immediately apparent or even occur in the same vicinity as their origin.

They are compounded as they move further downstream and impact individuals and ecosystems far removed from their source. This is why it is vital that we are cognizant of our actions and understand their far-reaching effects.

A river can be conceived as an ephemeral entity that is moving ever away from us, and with it, the potential to utilize and experience it on an emotional level. Because of this, we must tether ourselves to the river, as a way to inform our sense of place and identity.

3

4

TETHER is a long-term vision for urban renewal and environmental restoration, focused on the Hawthorne neighborhood of North Minneapolis. It seeks to repair the ecological and social fabric of the area, while creating educational opportunities and informing a sense of cultural identity strongly tied to the Mississippi River.

At the heart of this endeavor is an Environmental Research and Learning Center, occupying the site of a former concrete recycling facility. The building has three main functions which act together to support the goal of the project: RESEARCH, TRANSLATE, and EDUCATE. 12,900 sf of research laboratories allow for water testing and environmental assessment of the river system. 10,900 sf of office space is provided for the Minnesota Center for Environmental Advocacy, which is a local organization that works with the legislature to enact sound environmental policy.

18,500 sf of public gallery, exhibit, and event space provides social and educational opportunities for residents to learn about the Mississippi river and its history within the city. Gross square footage of the building comes to 49,550 sf. Total square footage of the site, including a public plaza and wetland pond, comes to 109,800 sf.

5

6

Site

Less than three miles from downtown Minneapolis, the site lies on the banks of the Mississippi River. The low-density residential Hawthorne neighborhood is cut off from the river by a combination of light and heavy-industrial land uses. As land prices continue to rise, and with the recent closing of the nearby St. Anthony Falls locks to boat traffic, the land use in this area may see some significant changes in the coming decades.

This is the impetus for TETHER, which explores what it means to live, work and play next to the Mighty Mississippi and to be a part of this vast, inter-connected natural system.

7

ST. PAUL

MINNEAPOLIS 8

Design Concept

9

Climatic Response

Site Response

10

15

14

13 7 6 7

6

9

3

12

10

15 4 3

N

11 1

2

N N

0

11

Ground Floor Plan

0

0

200 ft30 ft 30 ft

400ftft 60 60 ft

1 Entry 2 Entry Gallery 3 River Gallery 4 Event Space 5 Exhibit Space 6 Research Labs 7 Classrooms 8 Offices for Minnesota Center For

Environmental Advocacy (MCEA) 9 Exterior Courtyard 10 Exterior Terraced Seating 11 River Plaza 12 Loading Dock 13 Shared Kitchen/Lounge 14 Storage 15 Mechanical Room 16 Exterior Deck

16

8

9 14

5 15

10

11

N N

0

Second Floor Plan

0

0

200 ft30 ft 30 ft

400ftft 60 60 ft

12

URBAN PLAZA

ENTRANCE

ENTRY GALLERY

Roof overhang

Double-skin facade

Sun shade

13

South Elevation

TERRACED SEATING

RIVERFRONT TRAIL

RIVER PLAZA

River Gallery

14

15

Section-Perspective Looking South

Exhibit Hall

16

Measure 1:

Design + Innovation The main goal of the project is to raise awareness of environmental issues within the Mississippi watershed through the programming of both the Research and Learning Center and the site, while creating a building that sensitively responds to its environmental and social context.

The building concept blurs the distinction between architecture and nature by developing a language of symbiosis, in which humans and nature can coexist. It is physically integrated within the restored oak savannah/wetlands and plays an integral role in the stormwater strategy of the site. The building mass buffers from winter winds and opens out to the south to maximize solar gains, while a double-skin faรงade helps regulate indoor temperatures and air quality. The program is organized around limiting energy use. The exhibit hall and offices, which need a generous amount of daylight, are located on the second level and take advantage of light scoops, while the event hall and research labs, needing a more controlled environment, are located on ground level.

18

STORMWATER INFILTRATION PONDS GREEN ROOF / INTEGRATION INTO LANDSCAPE

MASSING AND ORIENTATION LOCAL MATERIALS CONNECTION TO NEIGHBORHOOD DOUBLE-SKIN FACADE

PUBLIC GATHERING SPACE BIKE / PEDESTRIAN TRAILS

N

19

Aerial-Perspective Looking Northwest

MISSOURI RIVER MISSISSIPPI RIVER

0-1.9 2-14

OHIO RIVER

15-38

ARKANSAS RIVER

39-155 156-336 337-663 664-885 886-1,270 1,271-5,540 (kg/sq. km/yr)

Nitrogen Loading of the Mississippi Watershed

20

Measure 2:

Regional/Community Design The site was selected for its land use and socio-economic issues. The residents have long been cut off from the river by US Interstate 94 and a section of industrial land that has been becoming less economically viable in recent years. The development strategy centers around the following priorities:

1)

The construction of a cultural building and plaza next to the river: This provides a muchneeded center for the community to gather, either informally or for large public events such as farmers markets and concerts.

2)

Increase access to public transit, jobs and affordable housing: Current walkscore for the site is 35, but projected to be around 80 with the proposed future development. This would provide a more sustainable framework for urban life in the area, giving residents the opportunity to live and work in close proximity, and lessen their reliance on automobile use.

3)

Provide river access: The proposal includes a series of pedestrian corridors that cross over I-94 and ultimately lead to the riverfront. The river and surrounding natural area, are used as learning tools which promote healthy lifestyles by connecting to the existing park and trail system, for which Minneapolis is well-known.

22

Measure 3:

Land Use + Site Ecology The site lies within the Mississippi watershed, the largest drainage system in North America (4th largest in the world) and touches 31 US states and 2 Canadian provinces. More than 50 major cities, including Minneapolis, rely heavily on the Mississippi for drinking water and yet it is still polluted due to agricultural and urban run-off. The pollution levels have gotten to the point where they have created an ever-growing dead zone in the Gulf of Mexico, which is one of the largest in the world.

The programming of both the site and building seek to mitigate this issue. It restores the damage done to the site by its industrial past, and returns it to a ‘performative’ environment that provides a place where natural vegetation, wildlife, and humans can coexist. It creates and maintains onsite ecosystems for native wetland plants and animals to thrive, while also tapping into a regional network of open spaces that are important in the migratory patterns of various local bird species, including the bald eagle.

24

Measure 4:

Bioclimatic Design Minneapolis falls in ASHRAE’s Climate Zone 6 and is characterized by significant temperature swings from winter to summer. Winter low temperatures are the main concern because they are usually coupled with high wind speeds. Summers can be very hot, but are less of a concern because they are short.

Using Climate Consultant to evaluate bioclimatic conditions in Minneapolis, weather conditions are within the human comfort level only 10% of the year. However, using passive systems such as solar heat gain and natural ventilation can increase this number to 37%. This still necessitates the need for active systems for the remaining 63% of the year, however, utilizing passive systems can significantly lower overall energy use.

The building massing and fenestration has been designed to deflect prevailing NW winter winds while opening out to the south. This maximizes solar gains in the winter, as well as views to the river and surrounding area. The NW façade has minimal glazing (except for skylights) and is largely buried into the earth. In doing this, the building utilizes the relatively warm temperature of the soil in the winter months to reduce the energy needed to heat the building.

N

W

E

S

26

Relative Humidity 100% 90% 80% 70% 60%

50%

40%

Sun Shading of Windows 0.030

70°

Comfort Ventilation Thermal Comfort Zone

0.025

60°

Internal Gains Wind Protection of Outdoor Spaces 50°

0.015

Passive and Active Solar 40°

Conventional Heating

Wet-Bulb Temperature (°F)

Humidity Ratio

0.020

0.010

30° 0.005

20° 10°

0°

10°

20°

Dry-Bulb Temperature (°F)

27

30°

40°

50°

60°

Evaporative Cooling

70°

80°

90°

High Thermal Mass

100°

0.000 120°

BUILDING IS PROTECTED FROM WINTER WINDS AND USES THE EARTH TO MINIMIZE HEAT LOSS.

37% AMOUNT OF THE YEAR PASSIVE SYSTEMS PROVIDE OCCUPANT COMFORT

SOUTH-FACING ORIENTATION MAXIMIZES SOLAR HEAT GAIN AND DAYLIGHTING, WITH VIEWS TO THE RIVER.

28

Measure 5:

Light + Air Due to the building’s position within the landscape, providing natural daylight and air to the occupants became a design challenge. During early programming studies, it became clear that daylight was driving the organization of the interior spaces. Support spaces moved to the NW perimeter while the most active spaces were pulled to the south and east. The building is organized around a radial series of sandstone walls which provide a clear spatial identity and orient visitors to the river through long, unobstructed views. Because of this, 92% of the floor area of the building has views to the outdoors. Skylights on the upper level bring additional daylight to the exhibit hall and offices. Overall, 71 % of the building can be entirely daylit during occupied hours.

The double-skin façade acts as an air intake, bringing fresh air into the building’s mechanical system and improving indoor air quality. There are intentionally few user-operated windows because the amount of time throughout the year in which passive cooling is beneficial, is very short. However, operable windows do occur in the second level offices. Because of this, only 2.1% of the total floor area is within 15’ of an operable window.

Daylight Study Model

30

31

92%

BUILDING AREA WITH VIEWS TO THE OUTDOORS

71%

BUILDING AREA DAYLIT DURING OCCUPIED HOURS

2%

BUILDING AREA WITHIN 15FT OF AN OPERABLE WINDOW

LIGHT SCOOPS BRING DIFFUSED LIGHT INTO THE EXHIBIT SPACE AND OFFICES.

OVERHANG BLOCKS HIGH SUMMER SUN WHILE ALLOWING LOW WINTER SUN TO REACH DEEP WITHIN THE BUILDING.

SUMMER BREEZES COMING OFF THE RIVER ARE USED TO PASSIVELY COOL THE BUILDING.

32

Measure 6:

Water Cycle The building’s water cycle utilizes the natural hydrology of the site. A series of stormwater detention ponds scattered throughout the oak savannah use biofiltration to naturally treat runoff and graywater from the building, potentially reducing the building’s water use by 50%. Minneapolis gets an average of 28.3 in of precipitation per year, with a 24hr 2-year event value of 2.3 in. The detention pond to the north of the building has the capacity to store and treat approximately 101,000 cubic ft of water, or 577% of building and site runoff. This means that it can also treat a significant amount of runoff from the surrounding urban environment. Once filtered, the water either infiltrates the soil and restores groundwater supplies, or is captured in cisterns beneath the building where it is used for non-potable functions such as flushing toilets and washing hands.

Harriet Island Outpost

34

577% 3

2

Stormwater runoff from adjacent development to the west directed into infiltration pond.

Excess stormwater runoff from building directed into infiltration pond.

4 35

STORMWATER MANAGED ON SITE

Water is naturally filtered through vegetation and course gravel to remove contaminants.

5 Water is directed to cisterns underneath the building. Excess water is allowed to filter through the soil to join ground water stores.

1 Extensive Eco-roof planted with native vegetation captures rainwater.

6 Non-potable water is used within building to flush toilets and wash hands. Greywater is then treated in biofiltration ponds, thereby creating a closed-loop water cycle on-site.

36

Measure 7:

Energy Flows + Energy Future The building uses both passive and active systems to minimize energy use, including berming up to the NW wall of the building, maximizing daylight, and the use of a double-skin façade. This façade helps to passively cool the building in the summer by allowing in breezes, and passively heat the building in winter by capturing solar heat and pumping it to other parts of the building through the mechanical system. It also utilizes a geothermal heat pump (GHP) system which takes advantage of the earth’s stable 54° temperature 10 ft below the frost line. Using a vertical closed-loop system (as opposed to a horizontal system) greatly minimizes the disturbance of the surrounding site during construction.

38

HIGH SUMMER SUN: 70°

DOUBLE-SKIN WALL CAN BE VENTILATED IN SUMMER MONTHS

BY ALLOWING IN FRESH AIR TO PUSH OUT ANY HEAT GAIN WITHIN THE WALL.

39

Cooling Strategy

LOW WINTER SUN: 20°

DOUBLE-SKIN WALL TRAPS SOLAR HEAT BETWEEN THE TWO LAYERS OF GLAZING. THIS WALL CAVITY IS CONNECTED TO THE BUILDING’S MECHANICAL SYSTEM AND THE HEAT IS PUMPED TO OTHER PARTS OF THE BUILDING.

MASS WALL ABSORBS HEAT AND RADIATES THIS HEAT WITHIN THE BUILDING.

Heating Strategy

40

Measure 8:

Materials + Construction Sandstone and concrete are the primary building materials. They were both chosen for their durability and their proximity to the site. The structural frame is concrete, with the bearing walls and piers clad in local sandstone. This sandstone increases the thickness of the mass walls and increases the potential thermal energy storage. It also conceptually ties the building back to the site, as the natural geologic formations in this area of the Mississippi river consists of striated layers of sandstone and limestone. The sandstone can be mined in nearby quarries, which minimizes the overall carbon footprint of the material by reducing its reliance on large amounts of fossil fuels needed to transport it to the site. This being an active public building, the selection of durable materials will ensure low maintenance costs and a longer overall lifespan than a building using an alternative structural system such as timber.

42

Parapet wall uses insulated concrete forms (ICF) to prevent thermal bridging.

Corrugated metal roofing with waterproofing membrane and 4� rigid insulation.

Double-skin facade with 3 ft air cavity. Outer lite of glass acts as watershedding surface and weather resistive barrier.

Air cavity acts as a thermal barrier. Interior lite of glass acts as both vapor and air barrier.

5

Sunshades protect wall from unwanted heat gain in summer months.

Wall is supported by verticallyoriented steel trusses located within the 3 ft air cavity at 12 ft o.c.

2

HSS steel columns on the interior of the walls provide additional support for roof structure.

Vent at bottom of wall allows in fresh air for building occupants, but also helps to regulate the humidity levels and mitigate potential condenstion problems within the wall.

43

0

4 ft

8 ft

4

16 ft

Inverted roof assembly with extensive eco-roof system and native vegetation.

Wood baffle drop-ceiling with track lighting provides some acoustic dampening.

One-way joist slab that has been post-tensioned to achieve spans over 36 ft. Rib joists span between beams at regular intervals.

Mechanical ductwork partially visible through drop-ceiling.

Poured-in place concrete wall and piers, faced with sandstone.

4 in concrete floor with river rock aggregate over 4� rigid insulation, waterproofing membrane, and crushed gravel.

Building foundation sits on concrete piles due to the building’s proximity to the river and possibility of soil erosion.

Tectonic Model

44

Measure 9:

Long Life, Loose Fit In a neighborhood that is constantly shifting demographically, the research and learning center is designed to be a place of timelessness: a constant part of life in North Minneapolis that links its residents to the Mississippi River’s past, present, and future. It is to be a place of social connection and cultural identity, and a symbol of acceptance of all people. The use of local sandstone adds to the timelessness and solidity of the building, rooting it in the natural geologic forces of the site.

46

Measure 10:

Collective Wisdom + Feedback Loops The impact of the building is spread beyond the site through the placement of 3 small outposts located at key points along the river as it flows through Minneapolis and St. Paul. Accessed by the existing walking and biking trails, each outpost offers a moment of re-connection and appreciation for the incredible variation of the river’s character while educating visitors about environmental issues. The first is located at St. Anthony Falls in downtown Minneapolis, (the largest waterfall on the Mississippi) the second is located at Mississippi Gorge Regional Park, (characterized by 100 ft tall sandstone bluffs) and the third at Harriet Island in St. Paul which is prone to flooding every spring.

Each site contains a water quality meter showing current contaminant levels so that the community can be actively engaged with the health of their river. This reinforces the reality that we are not removed from our effects on the natural environment, and must understand that our cities should be designed in an ecologically sustainable and socially-conscious manner.

Mississippi Gorge Outpost

ENVIRONMENTAL RESEARCH CENTER

MISSISSIPPI GORGE OUTPOST

ST. ANTHONY FALLS OUTPOST

HARRIET ISLAND OUTPOST

TETHER