William D. Cox

Construction Management

1099 New York Avenue

Washington, D.C.

General Building Data

Building Name:  1099 New York Avenue
Location: Washington, D.C.
Building Occupant: Tishman Speyer Properties
Occupancy Type: Office/Retail
Size: 173,260 SF
Number of Levels (Above Grade): 11
Number of Levels (Below Grade): 4
Dates of Construction: June 2006 through March 2008 (Estimated)
Building Costs: $31,600,000 (Total Cost of Construction)
Delivery Method: Design-Bid-Build with CM @ Risk (General Contractor)

Architecture

1099 New York Avenue is to be Tishman Speyer’s new premier office building located in the heart of Washington, D.C. near the newly constructed convention center. The ground floor will serve as a main lobby for the 10 stories of office space above and will include two retail spaces that will have separate street access located on both New York Avenue and 11th street. Below grade will be 4 levels of parking structure that includes a fitness center accessible to all future tenants. The entire structural frame of the building is composed of a cast-in-place concrete system that will be post-tensioned for additional strength.  

The cooling towers and emergency generator are located in the mechanical penthouse. Each floor is served by its own Air Conditioning Unit which is located in the centrally located in the core of the building. The fuel storage for the generator however is located on level B2 thus requiring a system of pumps for fuel to serve the penthouse.

Major national model codes used include the 2000 International Building Code and the Building Code of the District of Columbia.

The building is located in the Downtown Development Overlay District and the underlying C3C zoning district as defined in Title 11 – Zoning of the District of Columbia Municipal Regulations. No historical preservation considerations are necessary on this site.

The East and North Facades of the building are both EIFS since they cannot be clearly seen from the streets. The South and West facades, which face New York Avenue and 11th Street, differ however. They are comprised of a complex fish-scale glass curtainwall in which each panel overlaps another and not one piece of glass is located in the same plane. The roof is a built-up system consisting of a stone ballast on a filter fabric on moisture resistant insulation on a waterproofing membrane on the concrete deck. A concrete parapet lines the perimeter.

Project Team

Owner

Tishman Speyer Properties
1775 Pennsylvania Avenue
Washington, D.C.
www.tishmanspeyer.com

Architect

Thomas Phifer and Partners
180 Varick Street
New York, NY
www.tphifer.com

Civil Engineer

Wiles Mensch Corporation
11860 Sunrise Valley Drive
Reston, VA

Structural Engineer

Tadjer-Cohen-Edelson
1109 Spring Street
Silver Spring, MD
www.tadjerco.com

MEP Engineer

Syska Hennesy Group
11350 Random Hills Road
Fairfax, VA
www.syska.com

Lighting Designer

George Sexton Associates
2121 Wisconsin Avenue NW
Washington, D.C.
www.gsadc.com

General Contractor

James G. Davis Construction Corporation
12530 Parklawn Drive
Rockville, MD
www.davisconstruction.com

Building Statistics Part II

Construction Methods for Existing Conditions

The site for the project is located at the corner of 11th Street NW and New York Avenue NW in Washington, D.C. Neighboring on the east side is the Embassy Suites Hotel, a recently constructed 14 story structure. The only space between these two areas is a 10 ft public alleyway. To the north is another active construction site. This project began just weeks after mobilization on 1099 New York Avenue, so careful coordination had to be taken into consideration while excavating.

Due to a congested site, one of the north bound lanes on 11th Street will be closed for the duration of the project. This will allow for more flexibility in material staging and room for a covered pedestrian walkway. This way there is still a steady flow of pedestrian traffic. Because it is a downtown location, parking is scarce and only available at the meters on New York Avenue and the public parking lot across the street.

The relocation of existing utilities is minimal. Most will be cut and capped until reattached once sufficient construction has progressed. 

Demolition

An existing two story concrete structure must be removed before any new construction can begin. The building was formally a rental car dealer and had several marked parking spaces. Most of the paint used in the garage areas contained lead and had to be separated before removal from the site. All fluorescent light fixtures had to be removed as well because of the hazardous materials in the older ballasts. Below the structure was an abandoned fuel tank which had leaked into the soil over the years. Special precautions had to be taken as the soil was separated and removed.

Support of Excavation

Sheeting and Shoring was required for support during the temporary excavation. It was recommended in the Geotechnical report that a free draining sheeting system consisting of H beams, wood lagging, and appropriate bracing be used. The soldier beams must penetrate at least 5 feet below the lowest point of excavation and wood lagging should not be less than 3 inches in thickness. At least 3 or 4 tiers of tiebacks were required for lateral support. Pressure-injected anchors were installed at an angle of 15˚ to the horizontal. In locations where tiebacks cannot be installed, rakers and heel blocks were substituted.

The ground water levels were found to be at about 22 to 29 feet below existing surface grades. Because of this a sub-drainage system will be required. Ground water levels were required to be maintained at least 2 feet below the lowest excavation levels. The system consists of interior collector pipes below the lowest floor slab and perimeter footing drains. To avoid infiltration of fine size silts into the pipes, filter material was placed around them. Cleanouts were incorporated to facilitate flushing of the system.

Cast in Place Concrete

The garage levels are short-spanned reinforced concrete slabs varying between thicknesses of 4”, 8” and 12”. The typical bay size is 25’-0” x 30’-0”. Slabs on grade are to be 3,000 psi in strength whereas suspended slabs are 5,000 psi. 8” drop panels at each of the columns are incorporated into the structure.

All slabs above grade are 8” thick and scheduled to be post-tensioned with an effective strength between 100 and 1000 kips. The typical bay above grade is spanned longer and sized at an average of 25’-0” x 40’-0”.

Mechanical System

The primary Mechanical room for this project is located at the Penthouse.  Located there are (2) 1440 GPM 500 ton Cooling Towers which serve (15) Self-Contained Water Cooled Air-Conditioning Units throughout the building. The AC unit at the penthouse provides conditioned outdoor air to the smaller units at each of the 15 levels at a rate of almost 30,000 CFM. From each of these units, Variable Air Volume Boxes with Reheat Coils distribute air throughout the occupied spaces.

The Fire-Suppression system combined sprinkler/standpipe system. A dry system is required in areas subject to freezing such as the loading dock and garage levels, whereas all other areas are to have an automatic wet system.  A 6” fire service with backflow prevention will be provided.

Electrical System

The main service feeder for the building enters from the Pepco transformer vaults on New York Avenue at the B2 level. The service is a 3-Phase, 4-Wire, 460/265 Volt, 4000A Main Bus that steps down through (3) 30KVA, 3-Phase 460-208/120 V Transformers. The power supply for the retail area is separate from that of the office space. Emergency power is supplied by a 350/438 KW/KVA 480/277V Generator located at the penthouse.

Curtain Wall System

The curtain wall on the west and south facades is a very complex system. It consists of a “fish-scale” frame on which each corner (except for the upper left hand) on each piece of glass lies in a separate plane. Each panel is constructed of a high performance low-e coated insulated glass assembly which rests on structurally glazed aluminum frame.  The design of the system was completed by a separate architect and requires its own consulting firm. Because of the great detail required, phasing began before the building permit was even obtained. To keep the project on schedule, construction of the west and south elevations must begin as soon as the superstructure is complete and be erected simultaneously.  The system is being fabricated in Toronto and requires considerable coordination during the shipping, staging, and construction process on behalf of the contractor.

Transportation

The Building is served by four traction elevators at the core of the building. There are three passenger cars rated for a capacity of 3,500 lbs. whose hoist way rises from the B4 level to the 11th floor. The one service car is rated for 4,500 lbs. and serves all levels, including the mechanical penthouse.  All four elevator systems gearless and do not require a machine room. They are each rated as Class A Loading and are contracted to travel at a speed of 350 FPM.