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Building Statistics


Building Name:   Crystal Plaza II
Location/Site:  220 20th Street Arlington VA
Building Occupant:  Charles E Smith Commercial Realty/Vornado
Occupancy:  Multi Family Residential, R2
Size (Sq. Feet):    325,000 SF, previous 205,500 SF
Number of Stories:    20, 8 new, 12 original, 1 Existing underground parking facility
 Height: 218’ from street level to top of parapet, 196’ from street level to top of main roof
Primary Project Team:          


Charles E. Smith/Vornado
2345 Crystal Drive Suite 100
Arlington VA 22202


Balfour Beatty Construction
3924 Pender Drive
Fairfax, VA 22030


1825 K Street, N.W. Ste 500
Washington D.C. 20006

HOK (Hellmuth Obata Kassabaum) (design)
Canal House
3223 Grace Street N.W.
Washington D.C. 20007

Hartman Design Group (Interior)
111 Rockville Pike Suite 425
Rockville MD 20850




Tadjer Cohen Edelson
1109 Spring Street, 5th Floor
Silver Spring MD 20910


GHT Limited
1010 N Glebe Road Suite 200
Arlington VA 22201


VIKA Incorporated
8180 Greensboro Dr Suite 200
McLean VA 22102


1001 Connecticut Avenue NW
Suite 704
Washington D.C. 20036


Steel Inspections-      Hillis Carnes
Curtain Wall-             CDC
Construction-            TPSi

Construction Dates:  Start Date January 2008 with pre construction beginning August 2006, Completion Date Floors 1-3 Late June/Early July 2009, and Substantial Completion August 2009
Overall Cost:  $134 Million (Includes Soft Costs, fee, previous demo/site work/abatement, FF&E, allowances, GC’s, and land costs)
$82 Million (Total cost minus previous demo/site/abatement, owner provided items,equity, and land costs)
Building Cost:  $67.3 Million (Construction Costs Only)
Soft Cost: $19.5 Million (Design, bonds, permits, interest, ect.)
Project Delivery Method: Negotiated contract with pre-construction services.  Project to be delivered with a GMP with anticipated change orders around 5% of project cost



Design and Functional Components: 
Crystal Plaza II is a 325,000 square foot building located along Arlington’s 20th Street and Crystal Drive.  The original building was completed in 1969 as a 12 story office building.  Given Crystal City’s location near the Pentagon, it often housed overflow offices for the Department of Defense and other military personnel.  However, during the Base Realignment and Closure Act of 2005, many of the tenants were required to relocate to more secure locations, including the tenants of Crystal Plaza.  The result of this situation was to transform the existing site of Crystal Plaza II into a 266 unit residential tower in a prominent location in Arlington County featuring connections to the metro, proximity to Ronald Reagan National Airport, and direct access to the Crystal City shops. The current project uses the existing concrete structure through the twelfth floor with nine additional floors of post tensioned slabs to house the required 254 units.  The individual apartments range from studios to penthouse suites located on the uppermost floors.  A two story lobby with direct access from 20th Street, Crystal City Shops, and the plaza located behind the building greets its occupants with colorful terrazzo flooring and stone finish work.  Also inside the lobby will be a small retail area and a club room on the second level.  An underground garage will be available for the buildings tenants.  The exterior design was changed from the original precast and glass façade to a more modern and efficient curtain wall system.  The new look creates a dynamic difference between the new Crystal Plaza II residential tower and the surrounding office buildings of Crystal Plaza.  Also distinguishing it from other residential areas is the overall building height, which towers 7 stories above all the surrounding structures.    However, keeping with other sites in Crystal City, the project employs the use of an outdoor plaza area sheltered from the street that is shared with the other buildings in Crystal Plaza.  This is one of the lone commonalities with other sites in Crystal City.

Major National Codes: 
Arlington County 4.1 Process, LEED-NC Version 2.2, IBC 2003, ANSI, Fair Housing Act, N.F.P.A 12, 14, 20, 24, 70, and 101, SMACNA, ASHRAE/IESNA Standard 90.1-2004, Virginia USBC 2005, International Plumbing Code, National Electric Code, International Energy Code, International Mechanical Code
Zoning:  R2-Residential
Historical Requirements of Building or Zone:  None

Building Envelope: 
The exterior is comprised of aluminum storefront on the lower levels with stone cladding and aluminum curtain wall with operable windows on floors 3-19.  Balconies are also present for some of the units which use a similar aluminum framed, glass railing system.  The 1 ¼“ stone veneer cladding is attached to the concrete slab using double clip angles attached to 3”x3” steel angles.  A vapor barrier and 2” mineral fiber rigid insulation is also used.  The aluminum storefront and curtain wall come pre-manufactured with R-13 insulation in the aluminum spandrel panels.
Roofing System:
Given the design that includes an outdoor space and pool, the roofing system varies among the differing areas.  In areas subject to heavy occupant traffic, such as around the pool, a 4” concrete topping slab over 2”, R-10 rigid insulation will be used.  In areas of less traffic, such as the outdoor space, a raised paver system will be used with the pavers supported by pedestals over the same 2”, R-10 insulation.  In the areas receiving pavers or topping slabs the water proofing will be elastomeric membrane.  On the underside of all slabs with the R-10 rigid insulation, additional foil faced batt insulation will be used on the underside of the slab to give the entire roof an R-20 value.  As for the other areas including the mechanical penthouse and elevator machine room roof, a 4”, R-20 insulation will be used above the modified bituminous membrane roofing with ballast on top.



Primary Engineering Systems

Vornado/Charles E. Smith Commercial Realty, the owner, entered into preconstruction services with Balfour Beatty Construction, the general contractor, for Crystal Plaza II in August 2006.  Crystal Plaza II is a renovation/addition of an existing, 205,000 square foot, commercial structure located on 20th Street, Alexandria VA, within the area known as Crystal City, into a 325,000 square foot residential, multi-family complex.

The contract for Crystal Plaza II is a negotiated contract with preconstruction services provided by Balfour Beatty and delivered as a guaranteed maximum price of $67.3 million.  Crystal Plaza II presents the general contractor with many challenges, including the unknowns associated with renovation of an existing building and its attempt to achieve LEED silver.  Primary concerns are with the structural system given its original design and the numerous amount of penetrations that must be added to support the residential systems for the new building use.  Another concern is the installation of the curtain wall system while the upper floor slabs are being placed.  Because the lower floors are already complete, installation of the curtain wall system can begin immediately, however, additional protection and precautions must be used to ensure that the custom built curtain wall is not damaged.  This is accomplished by using a protective “brow” system that surrounds the structure at a given level.

The general contractor has supplied a two car, man/material hoist on the south side of the building that starts at the 2nd floor and includes a single jump from the initial height at the 12th floor to the final, 20th floor.  Also provided is a Peiner Model SK225 tower crane with a 268’ hook height and a 163’ boom length.  The crane is just high enough to place the cooling tower units alongside the penthouse on the 20th floor.  The crane’s primary use on site is for the concrete subcontractor, but is available to other trades until its removal in mid September.

Apartment units will receive 120/208 V, 125 A service via 19 meter centers located on each floor in the electrical closet.  Meter centers are broken into two supplies, one from floors 2-10 and a second for floors 11-19.  Meter centers are connected to a single, 3 phase, 5000 A switchboard by bus duct with a primary riser size of 2500 A and connection ducts of 600 A that is part of Dominion Virginia Power’s grid.   Estimated maximum load for this system is 1,514 KW.  The 277/480 V system provides power to many of the buildings mechanical and fire suppression systems.  Use of transformers also allows the voltage to step down for use in common area lighting and electrical systems.  The system is distributed through two switchboards with the first being the initial connection to service.  The first switchboard provides power to lower level systems such as the lobby and 2nd floor lighting/receptacles (via 150KVa transformer), 1st floor mechanical units, emergency systems, and the second switchboard located on the roof level.  Estimated maximum load for this system on the initial switchboard is 1,831 KW and 1,294 KW on the second switchboard.  Stand-by power is available through a 450 KW, diesel generator located on the roof in the machine room. 

The predominant lighting type for the apartment units is incandescent.  The public areas, such as corridors and the lobby, tend to use more fluorescent and high end, designer fixtures, when compared to the simple incandescent fixtures used in the apartments.  In the apartments the entry areas use 50W, PAR 30 bulbs in a recessed fixture, as do the shower and tub areas.  A 75W, A19 single bulb, pendant fixture is located above the kitchen island with 50W, MR-16 track lighting used around the kitchen and dining areas.  The bedrooms and bathrooms receive 40W and 60W, A19 bulbs in combinations varying from 2 to 3 bulb fixtures and are surface or wall mounted.  The closets and laundry rooms receive 7W, compact fluorescents.  Public spaces primarily use 25W or 32W, T8, 3000K, dual bulb, fluorescent fixtures running on 265 volts.

All of the major required equipment for the mechanical system is located in one of three rooms on the penthouse level.  Individual control for each residential unit is achieved using water source heat pumps located in each apartment.  The fresh air is provided via four roof top units supplying a total of 22,000 cfm with an EER of 9.8 and a total capacity of 417 mbh per unit using a gas connection. These RTU’s also provide supply air to the public spaces, such as corridors and the lobby.  A fifth, packaged RTU, is also located on the penthouse roof to supply conditioned air to the rooftop gym space.  This RTU uses electric heat and provides 2000 cfm.  The water source heat pumps vary in size from 1 to 5 nominal tons, have EER’s between 11.9 and 14, and use R410A, a non ozone depleting refrigerant.  Also, for controls the individual units utilize Energy Star compliant programmable thermostats.

The mechanical system uses two plate and frame heat exchangers to exchange heat from the heat pumps to one of two 400 ton, cross flow type cooling towers located on the west side of the penthouse.  Incoming water from the cooling tower is at 85oF, flows at 1200 gpm, and returns to the cooling tower at 95oF.  On the heat pump side, the entering water temperature is 100oF, flowing at 1320 gpm, and returns to the heat pumps at 90oF.  Hot water for the system is provided via four, natural gas, condensing fire-tube boilers also located in the penthouse.
Plumbing is divided into two zones, high and low, for supply to the apartment units.  The system uses the boilers and three heat exchangers to produce hot water that is then passed through an electronic mixing valve to achieve the proper temperature.  The 140oF hot water is stored in two 500 gallon tanks with two 80 gallon expansions tanks, all located on the 20th floor.

Given the nature of the Crystal Plaza II project, the structure can be broken down into two distinct sections.  The existing structure, from levels 1 to 12, is a 10” deep, rebar reinforced, two way, flat slab with drop panels around corner columns at critical points.  The columns from ground level to the second floor slab are 20” diameter, circular columns, while all other columns are square and 18”x18” for exterior or 20”x20” for interior.  As part of the renovation, carbon fiber reinforcing is used to assist the existing structure in the bearing capacity of the new structure and is applied to the columns under critical load.  Steel W shapes are used around slab cuts for the larger openings in the existing slab and include the use of W8x15, W8x21, W8x35, W10x45, W12x45, and W12x58.  A shear wall is also part of the renovated structural system up to the 12th floor.  Given the building’s new height, a 10” thick shear wall with #9 and #5 rebar spaced has been constructed.

The new structure is a 6”, post tensioned, 5000 psi, flat plate slab.  It has a design live load of 50 psf, including 10 psf for partitions, and uses 8000 psi concrete “puddling” over designated columns.  Columns are also reinforced with shear heads in all directions while other reinforcing in the slab and around openings is #4 rebar.  The post tension cables vary in stressing from 51 kips to 270 kips depending on location and direction.  The penthouse slab is an 8” thick, 5000 psi slab reinforced with #5 rebar.  The penthouse roof is a 12” thick, 5000 psi slab reinforced with #6 rebar.  The design live load of the roof is 60 psf, including the 30 psf snow load, and the penthouse floor has an increased design live load of 150 psf at mechanical equipment areas.  Also on the penthouse floor slab, the structure requires specially designed beams ranging from 12”x58” to a post tensioned 36”x48” beam for support of the swimming pool.  Columns for the new structure are identical in size to the existing columns below, however, use of sloped columns are employed at the corner columns on floors 12 and 13 to adjust to the new floor layout and structure.

Additional Engineering Support Systems
Fire Protection
The fire protection system for Crystal Plaza II is a design build system with only the pump room in the lower garage level shown on the construction documents.  The system utilizes both wet and dry systems.  In all locations that are temperature controlled, the wet system is used, while unconditioned areas, such as the garage, are dry to avoid the pipes freezing in low temperature conditions.  The wet pipes that travel through the unconditioned areas are insulated, heat traced, or both depending on the location.  The standpipe risers are all 6” in diameter with 2” branches to the hose valves located in the two primary stair towers.  The sprinkler heads branch off at each floor and include tamper switches before the first sprinkler head.  The dry system uses an oil-less air compressor to fill the lines for levels G1 and G2.  On the exterior of the building is a 4” fire pump test connection and a 4” Siamese connection for the local fire department.

The vertical transportation system selected for Crystal Plaza II is an innovative system that requires no additional machine room for the elevator equipment.  Use of Otis’s Gen II elevator system provides elevators that are 50% more efficient and travel at 400 fpm.  The travel at Crystal Plaza II is 211’-8”, with an overhead hoist way machine location, and is lifted by steel reinforced belts rather than steel cables.  Each car has a capacity of 3000 pounds and is powered by 480 V, 3 phase service.  Although no machine room is required, the designed elevator machine room will be used to house the elevator controllers for the system.

Telecom, Security, Other Systems
The owner has elected to provide the telecom and security systems used on the project.  They have selected Verizon as the telecom contractor, and Kastle Systems as its security contractor. Verizon will provide there FiOS cable system with high speed internet and Kastle will provide cameras and card readers for the entrances that will be monitored at the leasing office and the concierge desk in the lobby.  A final system is the centralized trash chute located adjacent to the single elevator bay for collection.



This Page was last updated on October 12, 2008 by Christopher Stultz and is hosted by the AE Department ©2008