Under Construction 2014
Opening Fall 2015
Located at the corner of Franklin and Portland Avenues in Minneapolis, the Rose is the fourth and final phase of the South Quarter redevelopment being carried out by Aeon and Hope Community Partners. The building consists of mixed income housing in two buildings, with 48 affordable and 43 market rate apartments. The building consists of efficiencies, one-, two-, and three-bedroom units, with shared amenities on the first floor. The affordable component will provide homes to individuals and families earning 30%, 50% and 60% of the area median income (AMI) and will also include 12 apartment homes for individuals and families experiencing long-term homelessness.
The project was developed and is owned by Aeon, and is intended to provide much-needed housing as well as aiding neighborhood revitalization. The project team includes MSR Architects, KFI, and Emmons & Olivier Resources. Early schematic design exploration and research was conducted by Mithun and Cermack Rhoades Architects. The project is being built by Weis Construction and will be completed in fall of 2015. The total development construction cost is estimated at $21,488,461 and design and engineering costs are estimated at $1,120,000.
The Rose is being built on a 1.65 acre brownfield site just south of downtown Minneapolis, and has a density of 55 units per acre. It completes the decade long redevelopment of the four corners of the intersection of Franklin and Portland Avenues known as South Quarter. Within the first three phases, Aeon and Hope Community have developed 120 mixed-income apartments and a mixed-use area with community gathering spaces (indoor and out), a corner market, and a child care center at street level. The final phase will add a community living room for residents, workout and yoga rooms, and a community garden.
The site design for the Rose is focused on three key amenities: First, the organization of the building around a central courtyard; second, a green blue scape that integrates planting and stormwater management; and third, a larger community garden. The building was designed to avoid shadow trespass onto the adjacent property.
During early schematic design, the project team evaluated the options available to close the hydrological system of the site as required by the Living Building Challenge Water Petal. The approach taken was to integrate potable and stormwater (rainwater) systems to meet 100% of resident needs without reliance on municipal sources. However, several barriers led to the team's abandonment of the LBC goal. They include regulatory barriers at the City of Minneapolis which severely limits grey water collection points; limited roof area for rainwater collection with respect to number of building occupants; and the combination of first and on-going costs (est, $2,000,000 construction, and $200,000 annual operating) of the systems to process grey water and black water on site.
The stormwater management plan for the Rose site integrates natural features on grade with an underground retention system to reduce quantity and improve the quality of water leaving the site. Three rain gardens capture water from the east quarter of the building roofs and have a capacity of 3,500 cubic feet (gallons). The gardens will be planted with sedges, coneflower and dogwoods depending on location and available sunlight. The underground retention system will receive the remainder of the water. It has the capacity of 6,500 cubic feet (gallons). A water quality unit will remove sediment; oil and trash from water before it filter into the soil or enters the city's stormwater system which empties into the Mississippi River. The system as designed will handle a 2-year rain event of 2.75". Expanding the capacity to a 100-year event would require 2.5 times the planned capacity. For zero run-off 3.5 times the capacity would be required. In addition to the estimated $1,000,000 in additional costs, expansion of the systems would reduce courtyard functionality and nearly eliminate all tree planting on site.
Reducing the overall energy use and cost for the Rose was a primary goal for the project. Aeon has estimated that it will spend $132 million on utilities for its portfolio over the next 30 years. At the beginning of schematic design a goal of net-zero energy was set. This goal was later revised to be net-zero ready and an energy use intensity (EUI) of 30 kBtu/sf/yr or less was targeted. This is a significant challenge. The project faces what some have referred to as the perfect storm, cold climate with long winters and hot humid summers; a building type with high energy use density driven by households; low regional fuel prices; and regulatory requirements from funding sources. The solution required a very aggressive yet thoughtful approach.
Keeping in mind the ultimate goal of a practical and replicable system, the project team used a data-driven process to maximize conservation and efficiency minimizing loads wherever possible. The largest energy load sources, such as heating and hot water, were targeted to achieve maximum effectiveness. Additional consideration was given to loads controlled by building management such as lighting.
The team used early energy modeling to examine the impact of six massing schemes on heating and cooling. The two-building east-west configuration is a direct result of this exercise. The orientation allows desirable solar gains in winter on the south facade, and limits eastern and particularly western exposures during summer afternoons when cooling demand is greatest. The spacing between the buildings is also optimized to allow sun penetration into the north building first floor south-facing apartments on the winter solstice.
The next step taken was the optimization of the building envelope. Again the team examined multiple options before landing on a solution that fit both energy target and the budget. The Rose will be built using advanced frame 2 x 6 16" O.C. spray foam insulated wood construction.
The ground floor walls are clad with Enduramax resulting in an R-39.5 assembly. Upper floors are R-31.5, clad with Nichiha fiber cement panels. The roof is R-80. The garage foundation is R-15, with R-10 below the slab. The windows are Pella Impervia U-value of 0.34, and a solar heat gain coefficient (SHGC) of 0.29.
Space conditioning within units at the Rose is provided by a variable refrigerant flow (VRF) system with heat recovery. The Mitsubishi R2 series has a 17.9 IEER and 3.4 COP. Fresh-air is provided to each unit by a central dedicated outdoor air system (DOAS). The DOAS has heat recovery with efficiency of 72% sensible/74% latent. The garage has a 92% efficient condensing gas boiler, with a heat loop with 29% efficiency. Domestic hot water is heated using 97% gas fired boilers.
Lighting power densities are reduced through the building. LED lighting will be used in common areas and for exterior lighting. Daylight controls and occupancy sensor throughout common areas are employed to meet the lower power densities targets. All appliances in the building were specified and will be field verified to be ENERGY STAR labeled.
A solar thermal domestic water heating system is located on the south face of each building. The system consists of 16 Kingspan Thermomax DF100 panels measuring 82" x 88" each totaling 800 square feet. It will provide an estimated 34% of the domestic hot water needs of the Rose. Running vertically just to the west of the entries, the systems are one of the most visible signs denoting the project's sustainability goals..
The Rose will continue to pursue renewable energy technology as it pursues a goal of net-zero energy over the next several years. The project faces a significant challenge-- the energy load requires a solar array three times the maximum available area on the site. Two primary strategies are being considered including a photovoltaic (PV) array to the roof of the buildings on site and the Living Building Challenge concept of "scale-jumping" or utilizing nearby rooftops for additional energy generation. Using a 10KSolar system, a 720 kW PV array estimated at 74,000 square feet (1767 panels) would be required to meet given loads. The roof will accommodate between 306 (simple installation) and 442 panels (construction of a solar hat). If scale jumping is used, area rooftops and other buildings in Aeon's portfolio would be employed to meet the remaining production need. [Note: All energy loads and production are yet to be verified and finalized.]
The modeled energy performance or EUI for the Rose is 35.6 kBtu/sf/yr (including the garage) before renewables, and 31.8 with the solar thermal. This is a 72% reduction (-79.9 kBtu/sf/yr) from the code baseline of 111 kBtu/sf/yr. The building easily meets the EnergyStar required reduction of 15% better than code. It will also meet the 2030 Challenge increased targets for 2015.
Water saving strategies for Rose apartments consisted of the specifying efficient flow and flush fixtures. (See Stormwater above for information regarding integrated water systems.) Fixtures selected for the Rose apartments are 1.5 gallon per minute (gpm) showerheads, 1.5 gpm kitchen faucets, 0.5 gpm bathroom faucets and 1.28 gallon per flush (gpf) toilets. The fixtures specified for the project satisfy the Green Communities advanced water criteria requirements. Modeled water use is 35 gallons/person/day (g/p/d) compared with the average water use of 69.3 (g/p/d).
Green Communities Criteria were considered the baseline in materials selection, and the Materials Petal of the Living Building Challenge was set as an ultimate goal. The approach to the Materials Petal focused primarily on interior finish materials with the greatest potential impact on resident health. The team identified 41 potential materials and products to investigate for selection of Red List Free alternatives. Items were ranked in order of magnitude of impact based on volume (drywall, for example) and known toxicity (paint and sealants containing VOCs, millwork and countertops known to contain formaldehyde, etc).
In addition to maximizing positive impact on residents, the advantage of this approach is scalability. Findings from this initial subset of materials can be incorporated into the entire building, multiplying the benefits to the project and the environment, and a clear dollar amount associated with each material upgrade helps to understand and manage costs.
Advocacy to building product manufacturers regarding the removal of Red List chemicals from their products is a fundamental part of the Living Building Challenge Materials Petal. To ensure that documentation was pursued and collected properly, a process diagram was developed showing the hierarchy of selection according to the Imperatives. This diagram (below) also assisted in communicating with the owner and project team about steps and requirements for qualifying within the Materials Petal. The team also developed and refined the Materials Tracker provided by ILFI to be more effective at communicating viable options to clients.
To be certified, all materials and assemblies must meet the five material Imperatives with full supporting documentation:
- Red List (Red List compliance)
- Embodied Carbon Footprint
- Responsible Industry
- Appropriate Sourcing
- Conservation and Reuse
Balancing cost and the priorities set for materials has presented a significant challenge to the project. As the project enters construction the realities of budget mean not all assemblies in the Rose are able to meet the Red List Free requirement. Check back for a post construction update.
|INDOOR AIR QUALITY AND OCCUPANT HEALTH|
As noted in the discussion of materials above, eliminating toxicity from the apartments was the cornerstone for the creation of health indoor environments. Prior to construction, the brownfield site was cleaned and soil remediation performed.
In units, windows provide daylight to all occupied spaces with the exception of the bathrooms which are located in the interior of the units. The vast majority of windows are operable to allow resident control of outdoor air. Operable windows were not included in all public areas where security is a concern.
A centralized ventilation system feeds filtered fresh air into each unit. The site location at the junction of interstates I-94 and I-35W favored a central system that allows for better air quality control. The air system has two filters points, a 2" MERV 8 outside and a 4" MERV 11 interior filter on the DOAS system. Units have exhaust fans in the kitchen and the bathrooms.
In addition to these systems the building also addresses resident well-being through the use of biophilic design elements as described in Biophilic Design: The Theory, Science and Practice of Bringing Building to Life, by Stephen Kellert, Judith Heerwagen, and Martin Mador. The design of the Rose incorporates concepts connecting residents to the rhythm of the seasons and the natural processes of the site. A prime example of this is the courtyard, which serves not only to organize the site formally, but allows the movement of light, air and water through site with seasonal variation. Designed for both children and adults, it utilizes natural forms and highlights the ecology of the site through the movement of water and variety of plantings.
The project includes a large community garden. The footprint of the garden is approximately 5,000 square feet (just over 1/10 of an acre) set aside permanently for agricultural purposes in a densely populated urban environment. The garden will be located at the northeast corner of the site to maximize sun exposure during the growing season—mid-May through early October. The design of the garden includes a covered patio for gather and a tool shed. Plans for the garden include garden plots, children's garden and larger areas of crops.
The community garden will be a focal point of the development, responding directly to the pre-development cultural audit that found area residents especially interested in the possibility of outdoor gathering spaces. The garden is a place for community members to gather as well as grow healthy food and learn about food. The new garden will be led by Hope Communities which has been engaging the community over the last five years on healthy food and food access.