School Without Walls

Washington, DC

Market Segment: Education

Branch: Limbach Mid Atlantic

Owner: CDC Public Schools

GC: Turner Construction

Architect: EEK Architects

Engineer: Limbach

Service: Design Build

Completion: 2009

Limbach DC: School Without Walls
Limbach DC: School Without Walls
Limbach DC: School Without Walls
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Company Profile

→DC Public Schools
→$3,700,000 mechanical and plumbing design and construction contract
→55,000 SF
→LEED Gold Certified
→Construction Completion: 2009

School Without Walls is a small District of Columbia public high school for grades 9-12 located at the heart of the George Washington University in downtown Washington D.C. This innovative school is based on the self proclaimed philosophy, “that life-long learning occurs both inside and outside the classroom.”

Business Situation / Challenge

The school was housed in a 120 year old building, vastly under-spaced and over capacity requiring an additional building to meet the demands of steadily increasing enrollment. However, the construction of this addition was contingent upon the premise that it remain architecturally consistent with the existing 19th century structure; which also necessitated minor interior modernizations along the same vain. The entire 55,000 sq ft. building site encompasses the original structure and the new “L” shaped addition. Along with Limbach Company, the building team for this undertaking consists of Turner Construction and the architectural firm EEK.

The challenge for Limbach Company was to develop an energy efficient system that preserved the architect’s design, while achieving a LEED Silver rating for the facility. As this is a school, creating a comfortable learning environment is also a top priority. Special attention must be placed on ensuring that all thermal and acoustic concerns are properly addressed. Furthermore, this design/build mechanical and plumbing project would need to be completed in time for the 2009 school year.

Technical Situation / Solution

In devising a solution that best satisfied the various obstacles presented in this project, Limbach utilized the relatively new technology of variable refrigerant volume (VRV) in their mechanical system. Extremely versatile and energy efficient, the VRV system employs cutting-edge heat recovery technology, enabling a single system to either cool or heat. The heat recovery function is achieved by diverting exhaust heat from indoor units in cooling mode to areas requiring heating. The VRV system keeps running cost at an absolute minimum by controlling each zone individually via an intelligent inverter. This inverter can manipulate the amount of refrigerant flowing through the system in accordance to fluctuating needs, allowing unoccupied areas to be shut down completely.

The VRV system provides 55 tons of cooling / heating for the building, while an additional 70 tons is supplied by 2 gas fired, 100% outdoor air, roof top units, which also deliver the ventilation air required by code.

In the interest of reducing water consumption, water conserving plumbing fixtures such as dual flush water closets and urinals, time metered faucets, and low flow faucets and showerheads were installed.


No major modifications are necessary for the installation of VRV systems and the need of large space consuming ductwork is reduced. Hence, it is equally suited for use in new buildings and in the restoration of existing buildings and thus, ideal for applications warranted by this project.

The nature of the VRV system not only reduces environmental impact, but will save School Without Walls significant costs, especially in comparison to other systems. MERV 13 filters will be installed on all permanent equipment reducing contaminates which can be harmful to the school’s occupants. Attention to maximized thermal comfort and acoustic design considerations will provide low noise levels and create a comfortable, optimized learning environment. Limbach Company’s design/build mechanical and plumbing project at School Without Walls has contributed to LEED points by utilizing an energy efficient, cost effective design and product.

Products and Services Used

→VRV system
→2 gas fired, 100% outdoor air, roof top units
→MERV 13 filters
→Water conserving plumbing fixtures:
→Dual flush water closets and urinals
→Time metered faucets
→Low flow faucets and showerheads