In the early 21st century, a derelict Centennial Mills is poised to become the center of a rejuvenated and regenerative River District. During the course of the design studio my classmates and I developed a master plan for the site. For my piece of the plan I designed an office space that incorporated one of the prevalent historic structures on the site, the original flour mill building originally constructed in 1910.
Measure 1: Design & Innovation
The Innovation engine is part of a redevelopment of an abandoned industrial mill complex on the Willamette River in the city of Portland. The principle issues associated with the site are rehabilitating the polluted soil, determining how best to reuse the historic buildings, developing the site in a way suited for the riverfront, and creating a master plan that facilitates economic growth. My efforts to address these issues include enhancing the site through ecological restoration; designing a building that reduces energy consumption and carbon emissions; and creating a program that promotes emerging businesses and professionals in the city of Portland.
A principal concept that highly influenced the design of the building was my idea for a new workplace, one that nurtures innovative ideas and fosters their growth in the digital age. I have proposed an office space with a unique program, one that combines coworking and regularly leased office space. I intend to create a synergy between the two, promoting the exchange of new ideas and experience. In order to be effective, this program needs the right environment which includes proper daylighting and environmental systems, as well as a site that connects to nature and the rest of the community.
Measure 2: Regional/Community Design
The site for the Innovation Engine is situated at a confluence of the Portland park blocks and the riverfront. It has the potential to be a major hub of activity but it has to overcome a couple of restrictive elements: several railroad tracks and an uninviting street front. To counteract these problems the master plan for this proposal also includes a bridge from the neighboring Fields Park to accommodate pedestrian access over the railroad tracks, open views through the site out to the river, and a parking strategy that creates a meaningful experience for those arriving to the site via car and bicycle.
The program is a mix of coworking and regularly leased office space where people and ideas can mix and be refined in an integration between the energy and community of a co-working office space with the experience and resources of businesses housed in regularly leased space. The building will provide space for the next generation of innovators in the city of Portland and is intended to be shared. The structure of the building and the lease strategy for the coworking spaces allows them to be used by the building tenants as well as the surrounding community.
Measure 3: Land Use & Site Ecology
The project is located on a brownfield site which will require remediation efforts of industrial waste that has been buried there over the years. Any development on the site will fund efforts that will improve its water and soil quality.
Most of the riverfront in Portland is protected by a continuous concrete wall that was built to protect the city from floodwaters. On this site there is a large inflection in the normally undeviating barrier, one that is used for the river ecology restoration as well as to create a path down to the river for the public. The sloped area will be planted with native trees and plants that thrive along the river banks including Oregon ash, willow, and big leaf maple. In addition, this inflection with its trees will provide a safe refuge for fish among the trunks and plants during times when the river is running high and fast.
Measure 4: Bioclimatic Design
Oregon has a mild climate and is ideal for passive systems. The atrium utilizes a stack effect to draw air in through ventilators in the exterior wall that pre-temper the air before it enters into the building providing natural ventilation year round. A high performance envelope coupled with properly shaded windows and thermal mass creates solar heat gain. Based on the ASHRAE Handbook of Fundamentals comfort model the building is expected to be passively controlled for 58% of the year. I calculated the Solar Savings Fraction for the building at 41% allowing it to avoid active heating for 67% of the year. In addition cross ventilation is capable of cooling the building as long as outside air temperature is 3° F cooler than the indoor temperature and can provide any needed cooling for all but 9% of the year.
To provide active thermal control there is hydronic heating in the concrete slab of each floor and chilled beams. Both strategies do not require additional mechanical ventilation to provide the needed heating and cooling and rely on water instead of air to transfer energy throughout the building. This combination of systems almost eliminates the need for mechanical ventilation.
Measure 5: Light & Air
The bioclimatic design of the building helps to aid in occupant comfort through its special attention to natural ventilation as well as by including systems that can be zoned to provide personal control.
As a project goal I wanted to ensure that as much daylight as possible would be allowed to enter the building during the cloudy winter months. To do so I included tall window openings on each floor to allow the daylight to penetrate the space as much as possible and top lighting through the atrium for spaces away from the building’s perimeter. The site’s SW/SE orientation makes daylight control difficult for the building. In order to properly shade windows and meet my goal of daylighting in the winter, I have incorporated an automated shutter system that allows the shutters to act as vertical shades for low angle sunlight when open, and horizontal shades for high angle sunlight when closed. This system can remain open on cloudy winter days. 86% of the regularly occupied space is daylit and 95% of these spaces have views to the outside with all of these views looking out to a park, the river, or the ecological restoration features on the site.
Measure 6: Water Cycle
The site is located on the banks of the Willamette River and as such has a very important responsibility to properly manage any storm runoff. Through various efforts the project aims to manage 100% of runoff from a 2 year, 24-hour event on site. The systems used to accomplish this goal are a large bioswale, a rainwater cistern to collect runoff from the roof of the building, and a retention wetland.
The building and site drain towards the bioswale and wetland area allowing all water from the site to be retained and filtered before it enters the river. The plants used in the storm water management features and overall landscaping are native plants to the Willamette River banks used appropriately to reduce dependency on irrigation during the summer. Any irrigation that is needed can be supplemented by the water stored in the cistern.
Measure 7: Energy Flows & Energy Future
The two principal areas of energy use that I targeted for reduction were electric lighting and heating, both of which are dependent on the window to wall ratio of the building. Early on, I made simple energy models to test different window to wall ratios for energy use. The two most applicable models were for 30% and 50% which resulted in 30.3 kbtu/sf/yr and 33.2 kbtu/sf/yr respectively. I decided to design with a target of 50% window to wall ratio because I wanted the increased daylight and views that comes with 20% more window area.
The atrium and tall windows along the perimeter allow substantial daylight into the building to reduce the overall lighting load and also provide passive solar gain. To help with energy consumption of electric lighting I included a PV system integrated into the skylights on the top level of the building. The system, according to the PV Watts calculator is capable of providing 174,011 kwh/yr which is 72.5% of the estimated 240,764 kwh/yr load for electric lighting. This lighting load would have been lower, but I expect the building to be used frequently in the evening by the coworking tenants and community members.
Measure 8: Materials & Construction
The building is designed to reduce overall material use and its carbon footprint. To do so, the structure of the building is a combination of wood and concrete. Both materials require no additional finish when they are designed and detailed effectively. Concrete is a carbon intensive material, but in some applications it cannot be replaced. Concrete is used for the first floor, the basement/parking, the stair cores, the elevators, and the hydronic slabs. The rest of the building’s structure is made of timber columns, beams, and CLT panels. The use of wood instead of concrete in these applications results in a net reduction of 19,134 MTCO2e.
In addition to my efforts to reduce concrete use, I also searched for ways that I could reclaim materials from some of the surrounding structures that would not be reused. There are many existing timber structural members that could be reused as long as they are deemed fit. There are also several buildings with grain silos that were built of 2x8’s layered together like a stack of cards. These old 2x8’s are used for interior finishes in the building.
Measure 9: Long Life, Loose Fit
The historic section of the Innovation Engine is viable for reuse because of the way it was built. It had a solid structure built of durable materials, open narrow floor plates, and good access to daylight and air. This type of building will always be able to be repurposed into something. The new addition emulates these characteristics in structure and program with a solid wood and concrete structure and a simple open plan with the intent that it will continue to provide the proper environment for industries of the future.
Even though the historic structure has value, it needs improvements to become a viable space for office work. The building needs seismic upgrades as well as improvements to its envelope. By making these improvements the historic section and the addition will be durable enough to last into the next century. By designing the high performance systems into the building it will ensure that the innovation engine continues to remain viable even if energy costs continue to increase over time.
Measure 10: Collective Wisdom & Feedback Loops
In past projects I learned that it is difficult to justify the use of an atrium in buildings. They are beautiful spaces that add to the aesthetics and environment of buildings, but are often difficult to justify from a cost standpoint. Some of the atrium spaces that I studied in preparation for this project were seldom used for anything but circulation. An atrium seemed like an effective solution to help bring in light and air to the building, but the only reason that it would work well in the case of the Innovation Engine because of my intent to use it as coworking space and a place for occupants of the building to have chance meetings and interactions. If the project were built I would want to observe how the atrium space was used and how effective it was at facilitating collaboration within the building.
I was also able to learn from the work that I did when creating energy models for the proper WWR of the building. Looking for ways to use glass judiciously is an important aspect of any high performance design and studying how the sun-shading and top-lighting strategies work could inform a lot of my future projects.