Government building design

When your client is the government, engineering design can be tricky, thanks to stepped-up regulations, budgetary concerns, and other considerations. Respondents discuss government, state, municipal, federal, and military facilities.

By Consulting-Specifying Engineer April 23, 2015

Respondents

  • Ian Bost, PE, LEED AP, Principal, Mechanical Engineer, Baird, Hampton & Brown Inc., Fort Worth, Texas
  • Robert Eichelman, PE, LEED AP Technical Director, EYP Architecture & Engineering, Albany, N.Y.
  • Paul W. Johnson, PE, LEEP AP BD+C, Vice President of Mechanical Engineering, Wood Harbinger, Bellevue, Wash.
  • Katie McGimpsey, PE, LEED AP, Principal, Affiliated Engineers Inc., Rockville, Md.
  • R. Scott Pegler, PE, LEED AP, Director of Mechanical Engineering, Setty, Fairfax, Va.

CSE: Please describe a recent government or military project you’ve worked on.

Ian Bost: We have recently designed two local county sub-courthouses. These were both two-story buildings with chilled water variable air volume (VAV) HVAC systems. Both buildings received U.S. Green Building Council LEED certification (Certified and Silver levels).

Paul W. Johnson: To serve the current Nimitz class nuclear aircraft carriers (CVNs) as well as the future class vessels, Naval Base Kitsap’s Pier B was demolished and replaced with a new state-of-the-art, 1,325-ft-long by 120-ft-wide concrete pier. Wood Harbinger provided rigorous and well-researched mechanical and electrical design for the extensive changes required by this upgrade. The future class CVNs demand twice the electrical power at three times the voltage, which meant major modifications to the upland underground medium-voltage distribution and mechanical utilities at Pier B.

Several other Navy facilities face the same challenging service demand changes, and Wood Harbinger investigated other upgrade attempts to provide a uniform approach solution to this larger scale issue. Electrical upgrades included a new 60 MVA, 34.5kV/13.8 kV/4.16 kV substation, a new generation of shore power mounds and substations, and changes and rerouting of the cross-base 34.5 kV distribution feeders between substations FG and H to the new 34.5 kV substation. Mechanical utilities distribution for pier and shore-side systems included collection, holding, and transfer (CHT) (septic sewage/saltwater mixture) systems; fresh water supply systems; storm drainage systems; pure water, steam, and pumped condensate systems; compressed air distribution systems; and associated appurtenances. The future class CVNs’ electrical requirements dictated a new 60 MVA, 34.5 kV/13.8 kV/4.16 kV substation and a new generation of shore-power mounds and substations. The upgrades required changes and rerouting of the cross-base 34.5 kV distribution feeders between substations FG and H to the new 34.5 kV substation. Substation 73 was replaced with a substation capable of supplying two CVNs with 13.8 kV and 4.16 kV shore power during maintenance. 34.5 kV/480 V substations and distribution were required for AOE and SSBN shore power and industrial power to support maintenance/repair operations. The mechanical distribution of pier and shore-side utility systems included: collection,holding, and transfer (CHT) (septic sewage/saltwater mixture) systems; fresh water supply systems; storm drainage systems; pure water, steam, and pumped condensate systems; compressed air distribution systems; and associated appurtenances. The new water and CHT systems were integrated with the existing systems. The engineering team added fresh water piping and utility connections along the waterfront, and provided drainable spill containment curbing for any drips occurring during hose disconnection. The steam and pumped condensate piping system was also integrated with the existing utilities. Steam piping was routed in a trench including an existing 4-in. pure water converted to a high-pressure return steam pipe. Steam utility connections including steam, high pressure return, and pumped condensate were provided along the pier. The compressed air system was routed in a mechanical vault, and trenches looped and connected to a new 10-in. compressed air main. The compressed air risers along the waterfront included outlets for ship service connection.

Katie McGimpsey: I recently worked on the John Edward Porter Neuroscience Research Center (PNRC) Phase II at the National Institutes of Health (NIH) located in Bethesda, Md. The PNRC Phase II addition is a 5-story, 320,000gsf state-of-the-art research facility that promotes world-class biomedical neuroscience research by enhancing interdisciplinary communication and collaboration. There is a 28,000-sq-ft animal facility and a 7,500-sq-ft imaging and behavioral suite, including an 18.4 T magnet. The building was constructed and is adjoined to an adjacent and occupied building. The central atrium has a 200,000 cfm smoke evacuation system. The design incorporates numerous sustainable initiatives to achieve LEED Gold certification and three Green Globes.

R. Scott Pegler: The most recent project was at the U.S. Census Bureau located in Suitland, Md. The building is just over 1.2 million sq ft. The work consisted primarily of troubleshooting some installation issues that were contributing to excessive equipment vibration.

CSE: Governments and military organizations frequently have to deal with limited budgets. How does an engineer on such a project stretch the engineering dollars-are there some areas where this is easier to accomplish than others?

Robert Eichelman: To effectively address budget constraints on any project, it must be done holistically with all design disciplines, as well as the cost estimator, owner, and construction manager, working together as a team. Initial construction and lifecycle costs for various system options, as well as their relative benefits, must be clearly defined and understood by all stakeholders to allow for informed value assessments. Early on in the process, the team should also discuss work or projects that can be deferred, as well as the approaches to allow for this work in order to minimize costs and impacts to future operations.

McGimpsey: Understanding the project goals and client requirements is especially important when designing to a limited budget. An opportunity to design shell space for a portion of the program presents an option to keep the budget in line, and still be able to maintain the engineering infrastructure integrity.

Johnson: It is most important to first understand the client organization’s expectations for both initial capital cost as well as long-term operating costs. We provide a range of options that try to balance initial capital cost with long-term maintenance and operating cost. The least initial capital cost option is normally a code minimum standard. The most cost-effective solution is to establish thorough and agreed-upon goals and expectations at the project outset so that we’re only designing it once. It is important to focus on capturing good cost estimates. The more complex the facility, the more crucial it is to get it right the first time because even minor changes can have an impact if systems are intricately interconnected.

Bost: There is a balance between cost and ultimate efficiency for mechanical equipment-finding the sweet spot is a normal project goal. Having the engineering disciplines involved from the very beginning of a project can help with budget establishment, and can be a great step in meeting the owner’s goals. It is easier to help the owner understand the possibilities and limitations of systems and equipment when this is done early in the project. On occasion, we become aware that a particular material or system cost has changed relative to comparable systems. By adjusting our specifications, we can help the owner take advantage of a price break that might be missed if every project was just like the last one.

CSE: How have the characteristics of government and military projects changed in recent years, and what should engineers expect to see in the near future?

Johnson: The military has definitely put a focus on sustainable design. The design standards have increased to show efficiency and sustainability. Other standards have been rewritten to better coordinate with NFPA and ASHRAE.

Pegler: I have personally seen at the federal level that both military and government project design guides and specifications have been revised to become more flexible for the engineers and designers, although both are still somewhat confining and restrictive. Some jurisdictions have adapted and in essence codified the "sustainable" practices and minimum energy consumption benchmarks, while others are fairly dated or nonexistent-it varies widely on the geographic region for municipalities.

McGimpsey: The idea of resilient design, meaning the capability of the built environment to resist (prepare for and adapt to adverse events) and rapidly recover from disruptive events, will be an emerging trend. Recent meteorological events, such as Hurricane Ike and Superstorm Sandy, have exposed the need to retrofit existing critical facilities and design new facilities with resiliency in mind. Resilient design principles look at various strategies based on size and time, and how basic human needs are provided for. Design engineers should also keep diversity, redundancy, simplicity, flexibility,durability, and locally available, renewable, or reclaimed resources in mind as these attributes all are inherently more resilient.

Bost: We have seen tighter budgets, greater emphasis on energy conservation,compacted design and construction schedules, and increased building security.

CSE: How does engineering systems for government (federal, state, and municipal) projects differ from military facilities?

Pegler: Most state and municipal governments do not require anti-terrorist force protection (ATFP) practices and consideration, while many, if not all, military facilities do. Federal government and military follow different, though in some cases similar, guidelines. Many military designs are dependent at some level on existing campus-type distribution systems for HVAC design (chilled water, hot water, and steam). Hours of operation for many military buildings are 24/7/365-not typically true of government buildings.

Johnson: Because of their mission critical nature, military facilities (Dept. of Defense) have requirements that are more demanding than what is required of normal government facilities.

CSE: Please explain some of the general differences between retrofitting an existing structure and working on a brand-new structure.

McGimpsey: The most obvious differences between retrofitting an existing building and working on a brand-new building revolve around the structural system, whether it’s preexisting or specifically designed to the project at hand. The available floor-to-floor height, floor plate size, column bay size, and the type of structure (steel versus concrete) all contribute to determining the type of engineering systems. Existing facilities usually dictate where major equipment rooms and vertical utility shafts can and cannot be located. Desired ceiling heights and available ceiling plenums also help determine if an all-air system or hybrid system, such as chilled beams, needs to be considered. Another important difference is the availability of building service utilities, whether there could be existing distributed campus utilities to tie into, or if a new building plant or extensive site work may be required to provide chilled water and steam and/or hot water.

Bost: One interesting aspect that we experience is deeper structural depths in older buildings but still a desire of higher ceilings, which causes design and construction coordination opportunities. We have had very good luck with a post-tension slab, and the constant slab and beam thicknesses, offering a more uniform ceiling space to route utilities.

Pegler: Coordination and negotiation of space for systems in new buildings is usually simpler and cleaner. So many existing government and military buildings were constructed years ago without the thought of some of the systems common in buildings today, namely information technology (IT) infrastructure (such as server rooms, cabletrays, etc.). Many were built without consideration for HVAC systems; when retrofitted, it was sometimes with window-mounted air conditioning units and wall/ceiling-mounted electrical conduit. These types of buildings generally have little to no plenum or shaft space to "hide" ductwork, conduit, or ceiling-mounted equipment. The challenge comes when a building is to be "improved" and it is difficult to convince our architectural counterparts that "visible" HVAC and electrical equipment is aesthetically acceptable.

Johnson: The biggest difference between existing and new structures is mitigating and planning around the unforeseen conditions that come with existing buildings. The idea behind a retrofit is that it will ultimately be less expensive than a brand-new structure, but unforeseen existing conditions can really derail a project budget and schedule.Thorough field investigation or an existing building commissioning program helps anticipate some of the field conditions to help make renovation projects go much more smoothly.

CSE: What unique tools, software, or systems do you use when specifying systems in or designing such projects?

Pegler: We look at the normal array of load calculation and energy modeling software. Photometric modeling software is also prevalent in our design development. Shading analysis software is occasionally employed. Computational fluid dynamics (CFD)software, though infrequent, is sometimes used to predict air diffusion characteristics.

McGimpsey: BIM has changed how buildings, infrastructure, and utilities are planned, designed, built, and managed. Affiliated Engineers Inc. uses Autodesk Revit MEP a sour design tool. We have also developed a proprietary, in-house energy modeling software for early conceptual modeling that can be carried through to design load calculations. We routinely use Autodesk Navisworks for clash coordination and simulated walk-throughs of our 3-D models. Routinely, military projects require the use of SpecsIntact; otherwise, we would use our in-house master specifications and incorporate client and project-specific requirements.

Johnson: Our analysis software tools are up to date and include an internally developed lifecycle cost analysis (LCCA) spreadsheet, WINLCCA and eQUEST (DOE-2 Thermal energy model). For specific project types, we also use other software tools such as Energy Soft’s EnergyPro and Trane TRACE. On specific electrical projects, we use ETAP power systems software for all of our load flow, protection coordination, and hazard arc flash analysis.

Bost: The majority of our new construction projects are using BIM (with Autodesk Revit).This software is especially useful when all the project team members are creating their work in 3-D. This project, in conjunction with Navisworks, has enabled us to more easily perform clash detection, and coordinate between the various disciplines. We have seen a reduction in the number of requests for information (RFIs) received during construction. In addition, we have started running detail take-offs of the equipment and systems in our Revit models. This has given us a better baseline for consideration of change orders.

CSE: Do you have less, more, or the same amount of freedom in specifying equipment and systems for government and military projects? Define the specification standards you must follow.

Johnson: There is always a requirement for nonproprietary equipment specifications. As engineers we provide our opinion based on experience we have with equipment and allow the owner to make an informed decision based on its purchasing requirements.

McGimpsey: In general, because both government and military projects must be competitively bid, design engineers usually have the same amount of freedom in specifying equipment and systems, as long as at least three named manufacturers are listed in the specifications. If there is an instance where only one manufacturer is available, a sole-source justification must be completed prior to bids. Typically, this path is not pursued since multiple bids usually keep the industry honest and fair in pricing.

Pegler: Generally less when compared to private projects. Building standards or guidelines do not allow for much deviation, although each project is different and the respective project manager (PM) may be inclined to permit waivers for specific circumstances. The federal government uses Facilities Standards for the Public Building Service (PBS P100) for most public buildings. The military uses Unified Facilities Criteria (UFC) with specific guidelines and criteria within branches like NAVFAC and Army/COE.