The RSF is a large-scale office building housing more than 800 people who support and conduct research work. The building also houses a data center that serves the entire NREL campus. NREL and DOE's goal is to transform innovative research in renewable energy and energy efficiency into market-viable technologies and practices. This building was conceived to serve as an example of these ideas and a living laboratory for the staff of the RSF to learn from and work by, providing a high-performance workplace and aiming at operating at net-zero energy on an annual basis.The building's narrow, H-shaped footprint Photo by Frank Ooms

The project is recipient of the 2011 AIA COTE Awards, and the article is an abbreviated version of the one posted on AIA’s web site.

As the client at NREL explained to the design team: "every design decision has an energy impact." The net-zero energy goal for this project amplified every design decision and explicitly shaped the building and resulted in a positive impact on the program and functionality of the building.

Rendering by VStudios, courtesy of RNL The building is a simple architectural response to the climate, site, and ecology that envelop it and the desire for a flexible, high-performance workplace within. Many of the integrated passive design strategies, such as daylighting and natural ventilation, strongly support both energy performance and human performance. The form of the building is driven by energy, with its long and narrow office wings connected by a central spine, forming an "H" shape. In fact, the building section was the first drawing sketched to understand how to harness passive energy.

The energy-driven form also facilitated significant building program and functional benefits. The open office plan resulted in a higher-density workplace, reducing the building footprint per person. The "H" shape provided secure separation between staff work areas in the office wings and collaborative public meeting spaces in the central collector. This shape also provided two exterior courtyards, which have become popular amenities.

The south wing features a transpired solar collector Image courtesy of NREL

The design began with the development of a simple energy model to begin testing design strategies and helped to quickly move toward a solution that was deeply passive, with a form and exterior envelope that was responsive to the climate, used water-based radiant heating and cooling systems, and decoupled the ventilation air from space conditioning.

Various systems and passive strategies were refined and developed the into a highly integrated singular solution. The design process was streamlined by the use of BIM across the design and construction team. Energy modeling in addition to simulations for daylighting, natural ventilation, thermal mass and the transpired solar collector continued to develop in detail, staying true to the design and serving as a continued performance evaluation tool for both the delivery team and the owner.

Land Use & Community

Courtesy of RNL 

Gabion walls like the one seen in this photo are made from rocks found on the site. Credit: Photo by Frank Ooms Integrated into an existing campus, the Research Support Facility enables previously separated staff to come together in one location. It creates outdoor pedestrian spaces designed to entice employees to utilize courtyards. Shuttles, city buses, bike parking, and minimized on-site parking opportunities encourage employees to use alternate methods of transportation. In fact, the bike parking is regularly full and in high demand.

Responsible to neighbors, the campus is careful to protect the existing wildlife and the community life surrounding this new facility. The community and local residents were represented, and their concerns were addressed, throughout the design process. The building height is kept lower than zoning codes allow to respond to the local community’s desire to maintain view corridors. Part of the project included the dedication of land area on the campus’s south table mountain mesa as permanent open space to extend an existing conservation easement.

Staff members can be seen enjoying lunch in this photo of the west courtyard. Credit: Photo by Frank Ooms

Site Description

The building and site are part of the overall ecosystem and are rooted with a strong sense of place. The building is formed around the forces and natural resources of the climate and the site. The building responds not only to sun and wind but also to the natural lay of the land and the context of the existing campus. The landscape design paid particular attention to natural stormwater management techniques, open space preservation, permeable paving systems, native landscape integration, use of high-albedo pavements, and the innovative use of onsite excavated rock for gabion walls.

The integration of the landscaping has already proven to be a successful creation of habitat, with frequent visits from a local herd of deer and other wildlife. The site creates a natural, beautiful and comfortable exterior space to enjoy while strongly contributing to the overall campus master plan.

Water Conservation and Use

Although rainwater cannot be captured, per Colorado water laws, the project still used the roof area of the project to determine a water use budget. In an average year, a little more than 797,000 gallons of water falls on the roof of the building. The building and site water uses are modeled at just over 791,000 gallons per year.

A combination of highly efficient plumbing fixtures, native and adaptive landscaping, and drip irrigation with a satellite-based smart irrigation controller were used to reduce building water use by 55% and irrigation water use by 84% compared to LEED baselines.
Aerial site plan and a variety of stormwater management strategies, including bioswales, porous paving, and roof drainage collection.
Courtesy of RNL

The site design for the project works in tune with the existing natural hydrology. The strategies include a series of rain gardens for roof drainage collection, porous paving within the courtyards, and bioswales to connect water collection points to the existing natural arroyo system of the campus. This allows precipitation to infiltrate the soil and take on patterns of drainage consistent with its pre-developed hydrology.

 

Energy

Achieving net-zero energy requires optimization and integration of all the energy flows and systems of the building with a reliance on many passive energy strategies. Lighting is an integrated system of daylighting, daylight control systems, occupancy controls, and high-efficiency lighting.

Thermal comfort is addressed using an integrated system of thermal mass, radiant slabs, night purging, and natural ventilation. Heating in particular takes a whole-systems approach to energy conservation. The building includes a large thermal labyrinth under the two main office wings. The labyrinth can store heat from the transpired solar collectors located on the south building facades. This heat is used to passively temper the ventilation air during the heating season. The labyrinth also serves as a thermal sink for reject heat from the data center, dramatically lowering the cooling load of the data center year round.Bioclimatic section with a variety of heating, cooling, and ventilation strategies explained.
Courtesy of Stantec

The building’s extremely detailed energy model predicts an energy use intensity of 33 kBtu/ft2/year. The onsite photovoltaic system is sized to meet net-zero site energy at an EUI of 35 kBtu/ft2/year. The onsite PV coupled with the passive strategies, such as thermal mass, natural ventilation, and daylighting, are also strategies for passive survivability in the event of a power outage.

Bioclimatic Design

The building is shaped around the climate to optimize passive energy strategies. The 60' wide section for the main office wings was driven by the objective to daylight and naturally ventilate the main office wings. The narrow footprint results in two long office wings oriented along the east/west axis and linked by a central connector space consisting of the lobby and conference facilities.
floor plans courtesy of RNL

The solar geometry of the site dictated the shading and daylighting strategies. The seasonal and diurnal temperature changes of the climate influence the integration of thermal mass and night-flush capability in the building interior and in the thermal labyrinth in the crawlspace. The geometry of the building was studied in a wind tunnel to fine-tune the effectiveness of the operable windows and cross ventilation, as well as pedestrian comfort in the exterior courtyards.

This building begins to hum as soon as the sun hits it, which is ideal given the number of sunny days in Colorado. The building creates its own electricity, heats its own ventilation air with a transpired solar collector, and shades all windows during the summer while providing an exemplary daylit space all year round.

Materials & Resources

The multi-story wall pictured in the photo is made from beetle-kill pine. Credit: Photo by Frank Ooms The incorporation of passive design features led to the narrow building footprint and to a correspondingly high quantity of exterior envelope. One of the largest challenges of the project was to design and construct the exterior envelope within the overall budget of the project.

One key strategy employed was the use of modular construction. The exterior wall is composed of insulated precast wall panels with finished interior and exterior surfaces. The other key strategy was to optimize the amount of glass and therefore not over-glaze the main office wings. The optimization of the glazing allowed cost control and solar gain control while maintaining fully daylit office spaces.

The material choices for the building were driven by the desire to have flexible and durable materials with low health impacts and reduced resource consumption. Construction waste diversion (75%), low-emitting materials, recycled-content materials (34%), regional materials (13%) and certified wood materials (59%) were all incorporated based on LEED compliance. Several highly visible, innovative materials were also incorporated into the project, including the use of reclaimed natural gas pipe as structural columns and beetle kill pine used as decorative wall elements throughout and as a multi-story feature wall in the lobby.

Staff members working in the open office area in the main office wing.
Photo by Frank Ooms Reclaimed natural-gas pipes were used as structural columns.
Photo by Frank Ooms

Design for Adaptability to Future Uses

Flexibility and adaptability are key sustainable design features but also very important workplace design strategies. The 60' deep office wings have column-free interiors, and the cores are small and decentralized to allow the basic core and shell of the building to have tremendous flexibility.

The workplace is designed with modular components, such as a raised floor, demountable walls, and modular furniture solutions. These systems make the workplace highly adaptable over time. These systems also created a very efficient space plan that allows the owner to add more occupants to the building with less overall building area.

The building is designed for a long service life of 50 years or longer. The main exterior wall finishes are highly durable, long-life materials, including architecturally finished precast concrete wall panels and natural zinc panels. The building is also designed to be expandable. In fact, a 138,000 ft2 extension to the building is already under way and is taking full advantage of the lessons learned from the original building. The building expansion is predicted to be 17% more energy efficient at a cost that is $13 lower per square foot than the cost for the original building.

Lobby features a wall made of salvaged beetle-kill pine.
Photo by Frank Ooms

Indoor Environment

The project utilizes strategies that leverage light and air to increase energy performance and improve workplace performance. Daylighting is the keystone strategy for the project because it significantly impacts lighting energy, cooling energy, and productivity.

The building massing and window design optimize control and harvesting of daylight. Virtually every workspace in the main office wings is daylit. Overall, 92% of all regularly occupied spaces are daylit. Air quality is enhanced by increasing the amount of outside air delivered to spaces.

All office spaces have 100% outside ventilation air delivered through an underfloor air distribution system. The ventilation system is decoupled from the space conditioning system, saving significant energy.

The building also has operable windows and is designed for effective cross-ventilation by using a narrow 60' deep floor plate for the main office wings. Effectively all spaces in the open office area, as well as the conference rooms and lobby spaces in the central connector space between the two main office wings, have excellent access to natural ventilation. A small icon appears on everyone’s computer informing them when it is an appropriate time to open a window.

 

Project details :

Owner : Department of Energy's National Renewable Energy Laboratory, Federal government.
Owner/developer (Director, Public Relations): Kerry Masson, National Renewable Energy Laboratory, Golden, Colorado, http://www.nrel.gov/
Occupancy : 822 people, 50 hours per person per week; and 60 visitors per week, 2 hours per visitor per week
Location: Golden, Colorado
Total project cost: (land excluded): $64,000,000
Total built area: 222,000 ft2 (20,600 m2) in a single building
Lot size: 4.25 acres, Previously developed land in a  suburban setting
Completion: June 2010

Project credits:

RNL
Denver, Colorado http://www.rnldesign.com/
Architecture: Richard von Luhrte, Architect,  Craig Randock, Architect (Lead Designer), Michael Simpson: Architect (Project Manager), Tom Hootman: Architect (Director of Sustainability).
Lighting design: Rachel Petro
Landscape architect: Marc Stutzman
Interior designer (Interior Design Project Manager): Wendy Weiskopf
 

Others:
Commissioning Agent: Michael Holtz, Architectural Energy Corporation in Boulder, Colorado
http://www.archenergy.com/
Contractor: Byron Haselden, Haselden Construction, LLC in Centennial, Colorado http://www.haselden.com
Structural Engineer: Brant Lahnert, KL&A Engineering in Golden, Colorado http://www.klaa.com/Civil Engineer: Duane Jansen, Martin/Martin in Lakewood, Colorado  http://www.martinmartin.com/
Mechanical engineer: John Andary, Stantec Consulting San Francisco, California  http://www.stantec.com/
Electrical engineer: David Knoll, Stantec Consulting
Energy consultant/ Plumbing engineer: David Okada, Stantec Consulting

 

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