Building Statistics

The LiUNA Headquarters is composed of the original 1959 8-Story Stone-Façade building and the new 8-story curtainwall addition. A mechanical penthouse is located on both structures. To match the original design, the addition will feature a steel-frame structure with composite CIP deck. The curtainwall addition stands to be the primary focus of this thesis investigation. The original building is located at the corner of 16th and I Street, with the existing main entrance located alongside 16th street. The main entrance to the addition will be from I Street. While the existing building is type IIA under the IBC, the project will be designed to meet Type IB construction under the IBC.

The two structures offer a stark contrast in façade styles, both representative of the time of original construction. The original structure features a limestone façade typical with the federal design of post WWII architecture in the Federal District. There are punctuated widows, and granite runs throughout street level and various ornamental locations. The stone veneer is 4” thick and is backed with 1” of grout and an 8” block wall. The existing glass windows are to be replaced as part of the renovation. The new structure, however, is entirely composed of glass curtianwall, allowing for a transparent appearance to the façade.

Both the existing and new structures feature open office plans, and both spaces share the same elevator, plumbing, and mechanical core located at the Eastern edge of the existing structure.

Major National Model Codes:

Building: The 2006 International Building Code, DCMR 12 Building Code Regulations (2008).

Electrical: 2005 National Electric Code

Fire: 2006 International Plumbing Code

Plumbing: 2006 International Plumbing Code

Mechanical: 2006 International Mechanical Code

Energy: 2006 International Energy Conservation Code

Handicapped: ANSI A117.1-2003 and the Americans with Disabilities Accessibility Guidelines for Buildings and Facilities (ADAAG), published July 23, 2004

Sustainability: DC Law 8-36 District of Columbia Environmental Policy Act of 1989; Green Building Act of 2006

Elevator Code: ASME A17.1 Safety Code for Elevators and Escalators

Zoning: DCMR Title 11 Zoning Requirements. According to the District of Columbia Zoning Map, LiUNA Headquarters is within zone district C-4, SP-2. C-4 is the retail and office downtown area of DC, and SP-2 is reserved for residential, non-profit, and trade association organizations. C4 requires a maximum height of 110’. LiUNA is 108’ to the top of the penthouse. The additional screened-in mechanical open-air space on the roof does not count against the overall height requirement.

Building Enclosure

In keeping with the modern style of D.C. architecture, the LiUNA Headquarters expansion will feature a prominent curtain wall system on the street-facing South façade. This curtianwall system is composed of a glazed aluminum frame with insulating glass units. The two main glazing types used on the project are designated as GL-1A and GL-1B. The design team specified the Viracon Insulating Glass Unit VNE 13-63 with various coating features for color effect dependent upon location within the façade. The wall assembly features ¼” glass, ½” of airspace filled with Argon gas, and another ¼” of glass with the coating. This system has a summer daytime U-value of 0.26 and 0.29 for GL-1A and GL-1B, respectively, thereby corresponding with R values of 3.85 and 3.45. The North-side façade will also feature the same façade system, but since that side will be shaded by the adjacent structures, it will not be exposed to the same solar heat gain load. As previously mentioned, the existing structure will retain the original 4” veneer limestone façade and the backing structure of 8” block. As part of the renovation, however, the existing window units and sills will be removed and replaced.

Atop the mechanical penthouse, there is a screened-in mechanical unit space and a green roof. The basic roof structure is composed of a 6” concrete slab cast in place with steel deck and hot-fluid applied rubberized asphalt, and 3” of extruded polystyrene foam insulation with an R-value of 15. At various locations where maintenance foot traffic is expected, there are 2” thick concrete pavers that sit atop shims to allow for water drainage. The green roof is composed of a 6” soil fill atop 2” of filter fabric. Sedum album and Sedum sexangulare compose 60% of the plantings; both are low-rise and low-maintenance ground covers.

Figure 2: Detail at Green Roof and Concrete Paver atop Roof Insulation

Throughout the rest of the roof, there is 4” of aggregate ballast specified to weigh 20 PSF with a bituminous membrane beneath the ballast. At roof penetrations, the bituminous membrane and an additional adhered uncured neoprene flashing are shown to extend beyond the initial penetrating vent stack or plumbing fixture as shown:

Figure 3: Roof Penetration Detail at Typical Vent Stack

Sustainability Features:

The LiUNA Headquarters is designed to achieve LEED Silver designation upon renovation. The design team is achieving this goal through the sorting and recycling of construction waste, specification of local and certified natural materials, regulating the indoor air quality, and integrating building occupant behavior and environment with sustainable-lifestyle choices.

Through the construction process, the construction management team is responsible for the storage and collection of recyclable waste from the project. Concrete, carpet, drywall, and other products of demolition will be sorted at on-site product-specific recycling bins sized by the design team. 50% of all wood products by cost must meet the Forest Sustainability Council (FSC) Certification. Furthermore, 20% of all building materials by cost shall be regional materials.

Within the mechanical system, a 21,000 CFM energy recovery wheel is to be installed and all filters will be MERV 13. Within the project specifications, limits were set on VOC architectural coatings according to 40 CFR 59 Subaprt D (EPA Method 24).

Given the urban site of the project, the building design team wanted to integrate a variety of city living and transportation options into the building. At least 5% of the parking spaces on the two levels of parking are designated as carpool spaces, and an additional 5% are designated as spaces for low emitting/ fuel-efficient vehicles. To encourage walking and biking to work, bike racks and showers are integrated in the design. Throughout the day, the building’s water consumption will be further reduced through the replacement of all existing water features and setting a flow limit of 1.5 GPM on all water features. Atop the mechanical penthouse, the green roof feature previously shown is included adjacent to the screened-in mechanical equipment station.

Construction Management

The downtown location of the LiUNA Headquarters required the General Contractor to comply with the District of Columbia Department of Transportation standards and guidelines for construction in the District. Most importantly, a Traffic Control Plan (TCP) had to be submitted to the District of Columbia showing the location of the tower crane, covered sidewalk protection, and jersey barriers surrounding the one lane of I-Street used as an unloading dock. When the loading dock was in use, a flagger was required by the TCP per the 2006 D.C. Temporary Traffic Control Manual.

As part of the renovation of the existing structure, the original façade of the 1959 structure was protected while the windows and sills were replaced. On the inside of the original structure, a complete renovation was performed complete with the installation of new systems and furnishings. Throughout all operations, an on-site recyclable separation facility was operated by the general contractor.

Electrical

Two electrical service mains provide 120/208 V, 3-Phase power to switchgear located in the P1 level electrical room. Switchboard A services all 3 elevators located in the core of the original building while the two Direct Outside Air Supply Units in the prefabricated mechanical penthouse are supplied with 120/208 V 3 PH power from switchgear B. A diesel engine generator is included in the prefabricated penthouse package.

Lighting

There were two lighting schemes in the building design: the lighting of the bellow-grade parking garage levels and the interior open-office floor plans. All “Back-of-House” or non-interior location light fixtures specified are manufactured by Lithonia. The primary outdoor-use lamps specified utilize (2) 32W T8 Florescent lamps manufactured by; these fixtures require an electronic zero-degree ballast

In the interior spaces, compact fluorescents with a CRI 80 minimum, CCT of 3500K, and 10,000 hours average rated life are used in the typical open office floor plans. At bathrooms, 16W 3000K fully recessed downlights work in alongside fluorescent wall mounted fixtures. Exterior LED fixtures flush with the roof terrace glass guardrail and at the canopy of the new building provide outdoor accent lighting.

Mechanical

Atop the roof of the 9th floor of the LiUNA Headquarters is a prefabricated mechanical penthouse featuring a chiller plant, boiler plant, heat recovery wheel, and air handling units. Within the chiller plant, two 302 ton evaporative condenser designed for a 78°F wet bulb work in tandem with two screw compressors, two barrel evaporators, and two chilled 1035 GPM water pumps. The boiler plant uses three natural gas boilers with three hot water pumps capable of providing a total of 340 GPM.

The Direct Outside Air Supply (DOAS) system driven by a direct drive FANWALL system is capable of providing 21,000 CFM to the estimated 1235 occupants. Heat transfer will be accomplished using either an air-side or a water-side economizer. Three water pump fan coils service the occupied interior spaces while four electric fan coils service the garage level zones. At the ninth floor conference rooms, two shut-off variable air volume terminals are specified for acoustical considerations.

The design team sought to earn 34% of the projected LEED points through efficiency in the mechanical design, the highest percentage of any individual section of the LEED program. The energy model projected a 21.9% reduction in energy consumption between the original building and design.

Structural

The bellow-ground parking garage is supported by 9” two-way slabs that sit upon concrete piers and foundation walls. At locations where the new structure meets the existing building, #5 rebar dowels are drilled and epoxied 12” O.C., eliminating the use of an expansion joint. Steel framing and composite deck provide gravity support while steel moment frames provide lateral resistance in the East-West direction, preserving unobstructed views through occupied floors. A combination of braced frames and moment frames provide lateral resistance in the North-South direction. These lateral systems work in tandem with the concrete core within the original building. The prefabricated penthouse and adjacent green roof are supported by a cast-in-place 9” NWC slab.

Fire Protection

The size of the building requires a pump with a flow capacity of 750 GPM; NFPA 20 requires that specified pump is able to provide 150% of the flow capacity at 1125 GPM. This pump is serviced by a 6” fire pipe at the water service room located on the 1st level of parking (P1) with an 8 GPM jockey pump. Automatic wet sprinklers are used in occupied spaces while dry sprinklers are used in non-heated spaces. In elevator machine rooms, 212 degree standard response sprinkler heads with heat detectors are specified. A two-hydrant flor test report was conducted at hydrants at 15th and I Street and 16th and I Street to verify available flow in case of emergency.

Plumbing

Since there are no new bathrooms within the building addition, the majority of the plumbing work involved the replacement of old fixture with more efficient, low-flush fixtures resulting in a total domestic demand of 160 GPM from the mater meter. A total water use reduction goal of 30% to 35% is identified in the projected LEED goals with the primary focus being in setting all fixtures used to a 1.5 GPM maximum flow rate.

LiUNA Headquarters Renovation & Addition

Washington D.C.

Josh Jaskowiak

Structures Option

Building Statistics