Carnegie Institution for Science – Mechanical and Finishes Upgrade
Design-Build General Contractor: Shapiro & Duncan, Inc.
Structural Engineer: Morabito Consultants, Inc.
Mechanical Engineer: Shapiro & Duncan, Inc.
Electrical Engineer: Engenium Group
Architect: Rippeteau Architects, PC
Contract Amount: $6,646,633.00
Start Date: 3/30/2016
Substantial Completion Date: 8/31/2017
The Carnegie Institution for Science is a limestone Beaux Arts National Register-listed landmark building in downtown Washington, D.C. Originally designed by Carrere and Hastings of New York in 1907, the building also has an addition by Delano & Aldrich of New York completed in 1937. It stands at the corner of 16th and P Streets, NW.
The owner knew the building’s HVAC systems were outdated and needed to be modernized so they procured an engineering study from Shapiro & Duncan for a high efficiency Design-Build HVAC renovation. The owner was also early in the design stage for a general renovation of office, lab and meeting spaces with the goal of reconfiguring work spaces to double the staff capacity, provide improved modern accessible toilet facilities, make all corrections to code deficiencies and provide new and refreshed finishes throughout. Seeing the opportunity for synergy in combining these two efforts, the owner wisely combined the two projects into one design-build project.
Given the magnitude of the work and the potential number of trade contractors required to execute it, the owner requested Shapiro & Duncan to be their sole source design-build general and mechanical contractor. We were comfortable accepting this challenge, as we have a long history of successfully completing similar projects for demanding owners.
Challenges
Our biggest challenge was the planning and coordination required to properly phase the project to meet the owners schedule constraints, including Carnegie weekday working staff; daytime and evening conferences and lectures; wedding celebrations on weekends while of course maintaining services and space conditioning. Working as a team of owners, designers and contractors through collaboration we were able to create a schedule for the design and construction which met the owner’s needs.
Pre Phase 1 was complete and Phase 1 was well underway long before the subsequent phases were completed in design. This put a lot of pressure on the design team and owner to finalize design so that pricing could be completed and materials and equipment procured to meet the constraints of the construction schedule.
In addition to overcoming these logistical hurdles, another challenge was figuring out how to hide close to 3 miles of refrigerant piping and where and how to install HVAC equipment without interrupting the historical character and finishes of the prominent Rotunda area. A considerable amount of design-related research would be needed in order to identify the best places to locate the new components and equipment.
Due to the layout of the building, the need to maintain historically significant architectural structures, and the challenges posed by working in the tight confines of a century-old building, opportunities for prefabrication would be limited.
Moreover, as constructible opportunities would be brought to light by our design and installation teams following initial demolition, the owner would have to show a high degree of flexibility to make the most of these ever-evolving opportunities.
Solution
As the General Contractor, our scope included modernizing select areas of the building including office suites, science classrooms, lab areas and gang bathrooms. Our team oversaw and managed more than 30 trades.
The first step in executing the design-build solution for the mechanical and plumbing systems was partnering with the owner to perform an engineering survey. The goal of this survey was to evaluate existing mechanical and plumbing systems and provide three construction solutions in each task area. This field survey was used in place of our usual computer-based Building Information Modeling (BIM) approach.
Results of this survey provided the impetus for:
- Replacing a four pipe HVAC fan coil system with a variant refrigerant flow (VRV) multi-split air conditioning system eliminating the existing chiller and boiler;
- Adding a code-compliant ventilation system by furnishing and installing two new dedicated outdoor air system (DOAS) rooftop units;
- Replacing the existing auditorium air handler with a single-package rooftop unit (RTU);
- Providing direct digital controls (DDCs); and
- Cutting in mechanical closets, through existing two foot thick masonry walls located in the high-profile Rotunda area, to house two new VRV air handlers.
Creation of the mechanical rooms in the rotunda required a cautious approach, due to the owner’s apprehension about cutting into the historic walls. When making the first cut, instead of taking out large portions of the wall, our team maintained the owner’s comfort level by making a small opening to survey what was behind the wall and ensure preservation. Fortunately, we discovered concealed voids in the structure large enough to accommodate our needs so full doorways were cut.
Great care was taken in both the design and installation of mechanical units and diffusers, which make them appear as if they were always there.
Results
Tom McDonaugh, a Carnegie engineer performing as the owners’ representative, was instrumental in the success of this project. With his construction knowledge and experience, he was able to play a hands-on role in the project. In a testimonial letter to Shapiro & Duncan’s CEO Sheldon Shapiro, McDonaugh wrote: “. . .Your people performed admirably. You, sir, have assembled a truly professional team, all of (whom) perform their duties and carried out their responsibilities enthusiastically while demonstrating exceptional expertise in their assigned areas.”
At times, the construction process was slow due to the complexities of the project, but clear communication among all team members kept our mutual efforts continually moving forward.
