An Architectural Perspective: Office Buildings 2011 By Donald R. Powell, AIA

January 2011

CHAPTER ONECommon Sense Office Design: Universal Appeal

Modern design and construction techniques have relaxed many of the constraints that formed the basis for 21st century office building design. Low-rise, mid-rise and high-rise office buildings serve a variety of end users and each require individual analysis. There are, however, certain universal guidelines that organize the building infrastructure and reinforce the perception of rational planning and flexibility. Lenders, developers and corporate design managers strongly endorse several time-tested and generally accepted truths referred to herein as the pillars of design.

The first pillar of design is the concept of right-sizing the floor plates to correspond to the needs of tenants in the submarket being served. Floor plate sizes vary by market segment and should be tailored to

accommodate large tenants, average tenants and desirable minimum-size tenants. 25,000 to 28,000 Rentable Square Feet (RSF) per floor plates are considered average for office buildings. The core to glass dimension is critical. 42’ from the core to glass is desirable for tenants utilizing primarily private offices. 47’ from the core to glass is more desirable for users who incorporate significant open workstation areas in their layouts. There are exceptions to every rule, but upon closer inspection one will find that the guidelines are generally scalable, for example, corporate campuses are often low-rise structures that honor the principals outlined herein by linking multiple floor plates, like “box cars”, resulting in 50,000 to 75,000 to 100,000 RSF floors.

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2 The second of the design pillars is the 5’ x 5’ planning grid. Space planning efficiency is perceived to be optimized by superimposing a 5’ x 5’ planning grid on the entire floor plate for office buildings, regardless of class or

status. That axiom does not necessarily inhibit freethinking about the shaping or massing of an office tower, but exterior designers must carefully consider the impact to space plan-ability and demonstrate adherence to performance standards when deviating from orthogonal geometry. Standardized glass sizes are inseparably coupled with the planning grid discussion. Building maintenance and operations personnel must purchase attic stock for each unique glass light size. Therefore, while the perimeter wall may deviate from the grid, glass sizes and mullion spacing should track the 5’ module whenever possible.

The third pil lar is the core should be centrally located. With the elevator lobby ideally positioned at the mid-point of the core. Larger tenants want direct elevator lobby exposure to their entrances. When

several tenants share a common corridor, it is important to equally share access to the elevators, toilet rooms and the service elevator vestibule. Exit stairs are ideally located within the center core, but the locations are subject to the building code requirements for minimum separation. To minimize the common area corridor, attention should be given to shape of the building or the floor plate size. Either of these can dictate if one or more of the stairs should be disconnected from the central core. There are exceptions to every rule, such as the circumstances that warrant a side core or end core location. Generally, the center core office plate is most efficient and readily adaptable to changes desired by tenants.

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One Victory Park Granite Park ThreeNEC America Headquarters

The seventh pillar is sustainability and pursuit of Carbon Neutrality. As of 2011, the United States Green Building Council LEED certification program has permeated through the entire office market. All office

buildings currently under design are pre-registered and are being planned in accordance with LEED criteria. The goal of reducing the impact of new construction on the environment is becoming a reality. With the initiative of LEED certification for Existing Building Operations and Maintenance (EBOM), it is conceivable that the movement will continue to grow. Green Power sources are becoming mainstream and the notion of acquiring Carbon Credits is gaining momentum. Recent advances in electric automobile design and growing acceptance of alternative methods to produce electricity will dramatically reduce the carbon footprint of commuters. Reducing the heat island affect of urban areas through green roof designs coupled with high performance building materials and further refined MEP systems will further reduce our consumption of fossil fuel and accelerate our path to sustainable communities.

The four th pil lar of design is the 30’ wide structural bay. Private offices are predominantly 10’ wide or 15’ wide. Corporations tend to group 10’ wide or 15’ wide offices on the perimeter. While on

occasion, a 25’, 35’ or 40’ wide column grid may satisfy a particular users needs, lenders will discount the value of buildings that deviate from the 30’ bay due to negative exit strategies. While perimeter columns are unavoidable they can and should be shaped and properly oriented to minimize tenant-planning disruptions.

The fif th pillar is column free interior spaces. Structural engineering technology advances have increased span lengths from the exterior wall to the interior side of the building core walls, thus un-incumbering

tenant layouts. In most cases, no more than 4 interior columns will be located outside the core area. Structural framing preferences vary by city and region. In north Texas, a 21” deep concrete frame utilizing post-tensioned wide-pan joist and post-tensioned girders is dominant. Consideration for construction logistics related to “flying” the concrete table forms can significantly reduce the cycle time for forming, placing and finishing elevated concrete floor slabs.

The sixth pillar is overhead HVAC distribution is the current standard for speculative office buildings. Recent advances in under-floor HVAC technology have begun to challenge this status quo in corporate office build-

to-suits, but lingering questions about broad market acceptance have to be recognized. There are many reasons to continue developing underfloor HVAC systems:

• reduced floor to floor height

• individualized air volume controls

• reduced energy consumption and operating costs

• better indoor air quality

• greater flexibility for moves and changes

• and enhanced capability for architectural floor treatments

Some traditions are slow to change, and there is a great deal of resistance to change in this arena by tenants, building owners, brokers and interior architects. Perhaps the goals for sustainable design will influence the market perception of underfloor air.

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An Architectural Perspective: Office Buildings 2011 By Donald R. Powell, AIA

January 2011

CHAPTER TWOAn Architectural Perspective: Class A versus AA (Trophy Class) Office Buildings

Defining the criteria by which we judge the quality of office buildings is often tainted by marketing spin and attempts to justify higher rents for buildings of lesser value. One can understand the logic of a prospective tenant saying, “I know a trophy class building when I see it, but I cannot tell you specifically what sets it apart.” This chapter outlines some of the definitive elements that separate Class A from AA, but it remains the “wow” factor that sets them apart.

Perception The initial “wow” moment may come as one perceives the building from a half-mile away, or upon arrival at the motor court, or when the grand lobby unfolds before them. An extraordinary impression is the minimum standard. A memorable experience that will last for decades is more aligned with the notion of AA or Trophy Class.

“Iconic architecture” is a term that is used far too often. One’s ability to describe a building using a few carefully chosen words, or a sketch that is immediately recognizable with a few strokes of a pen begins to illustrate the idea of iconicity or correspondence between form and meaning. Can an office building measure up to the standards historically reserved for religious and cultural symbols? The simple answer is, probably not. It is, however, more realistic to simply compare office buildings to one another. Today, modern cities are recognizable by the silhouettes of office buildings in much the same way that cathedrals defined European cityscapes of the past. On that basis, office buildings can become significant and breakthrough to iconic status. Corporate image is enhanced when a building itself becomes meaningful to a community, a region, a country or globally.

Petronas Towers

Transamerica BuildingBurg al Arab Hotel

Singapore Bay Sands Hotel & Conference Center

Chrysler Building

An Architectural Perspective: Office Buildings 2011 By Donald R. Powell, AIA

January 2011

Reality: Outward ExpressionAt some point the class comparison discussion centers on tangible elements. The “wow” factor is important to the observer on several different levels. A building can be recognizable on the city skyline or within its neighborhood context. The manner in which the building profile pierces the sky or the illumination of architectural surfaces at night can establish a distinct office building identity from blocks away. Conventional thinking for a Class A office building envelope would dictate a modest expenditure of one-half to one and one-half percent of the core and shell budget for architectural elements located above the highest occupied floor. Rooftop mechanical and elevator equipment rooms are always carefully screened and integrated architecturally with the body of the building and in accordance with the style of the architecture. Class AA office buildings frequently celebrate the top of the building by employing soaring planes of glass and metal to establish a unique signature element on the skyline. Three to six percent of the core and shell construction budget may be expended for the skyline “move”. Trophy Class buildings deliver multiple layers of detail and complexity starting at the base or podium, with threads of primary, secondary and tertiary elements rising through the body and culminating in a visual crescendo above the roof line.

The base and body of a Class A office building must deliver its’ own architectural message to the observer. While the budget normally dictates other than a comprehensive granite and curtainwall envelope, the street level entrances and storefront openings should announce Class A quality through granite details in casings, sills and frames. The podium and body fenestration should incorporate primary and secondary architectural grid elements to organize and humanize the scale of the building. Properly detailed and finished architectural precast concrete can be viably integrated into a Class A building façade.

Trophy Class building facades are high performance, elegant, and exquisitely detailed. Granite, metal panels and glass are primary spandrel materials with curtainwall quality glazing systems employed at all windows. Sun control and “day-lighting” devices in the form of eyebrows and fins, second layer skins (sometimes referred to as architectural sunglasses), shadow box spandrel systems and rain screen systems may all be used to convey social awareness and support sustainability concepts. The envelope of AA Class office buildings is generally one-and-one-half to three times the cost of Class A.

Corporate signage is often considered mandatory under lease terms. When properly integrated, signage can reinforce architectural hierarchy or emphasize an important element of the design. A signage belt course at the top of the podium or a monolithic façade element can serve to ground the signage while adding variety and hierarchy to the overall fenestration. At its best, signage adds to the perception of quality and stability. There are numerous office buildings, such as the Transamerica Tower, Citicorp Headquarters, or the Chrysler Building, that have become meaningful symbols of the corporations they serve.

When you’ve Arrived: the Public Side The arrival experience is very important to both Class A and AA building occupants. Since Class A buildings generally don’t compete in the marketplace with those buildings adorning the skyline, it is likely that the initial impression of a Class A building may be formed at the point of arrival. Class A building entrances must be smartly landscaped with enhanced paving, stylish outdoor furniture and architectural lighting. A visitor or prospective tenant should find convenient parking or standing space close to the front door. The main lobby of a Class A building should be inspiring and reassuring, with no less than 2,500 SF of floor area, 14’ minimum ceiling heights, granite flooring, comfortable seating groups and high-end architectural finishes throughout. Class A buildings should utilize a revolving door at the primary entrance with vestibules at secondary entries. The lobby ceiling should be treated as an important surface and thus incorporate articulated gypsum board planes and custom lighting.

The Trophy Class building arrival procession should incorporate a significant motor court, porte cochere, a water feature, note worthy public sculpture and, through skillful manipulation of the aforementioned elements, evoke the second “wow” sensation. Valet parking should be provided, although visitor parking in a parking structure can be effective if the space is properly finished and lighted, with an elegant vestibule connection to the lobby. Classical background music and scented paths from the garage to the lobby may be incorporated to enhance the sensory perception.

The lobby of the Class AA building must reinforce the stature of the building and create a memorable impression. The scale of the lobby is critical. Ceilings 18' - 20' create the sixth surface of a space expansive enough to overwhelm the observer. Granite floors should be provided throughout except for wool carpeted inlay areas at seating groups. Five-star hospitality quality is the standard for finishes, lighting, and furniture. A lobby concierge/security station should be visible and convenient to guests and tenants.

An Architectural Perspective: Office Buildings 2011 By Donald R. Powell, AIA

January 2011

The ground floor elevator lobbies in Class A buildings should be impressive to guests and tenants. Elements should include 12’ high gypsum board ceilings with custom lighting, 9’ high by 3’-0” wide elevator doors with integrated transoms, custom hall lanterns, stone walls and floor, stainless steel elevator doors and jambs. Class AA ground floor elevator lobbies should make a powerful statement in terms of scale and finishes. A minimum 15’ ceiling height with articulated forms and surfaces including a combination of metal panels, meshes, woven metals, sculpted gypsum board and custom lighting is considered the norm. Elevator door openings should disguise the 9’ elevator height and express a full-height opening from floor to ceiling. 3’-6” wide elevator door openings with stone jambs and custom etched or textured stainless steel doors, custom hall lanterns, custom call buttons, and display opportunities should be incorporated. A public area art program should be considered in either scheme. Class AA buildings should incorporate museum quality sculptures and paintings equating to at least 1% of the gross construction cost.

Getting Down to BusinessTypical office floors are designed according to the leasing strategy for both multi-floor tenants and multi-tenant floors. There are three common area components to be addressed; the elevator lobby, corridors, and the toilet rooms. Class A elevator lobbies should feature custom ceilings shapes and recessed lighting, with painted elevator doors and frames. Elevator lobby floors are designed for carpet inserts within thin-set stone tile borders. Wall finishes are planned for upgraded vinyl wall coverings and wood base. Class AA elevator lobby finishes should a mimic the ground floor lobby quality including a custom ceiling treatment, stone floors with wool carpet inlays, stone or wood base, stone or wood wainscot, stretch wall acoustic fabric panels above the wainscot, stainless steel elevator doors and jambs, and custom hall lanterns. Multi-floor tenants frequently reserve the option to finish the elevator lobby to match the balance of their space.

The building corridors should be 6' wide with 10' high ceilings. Class A floors utilize carpet flooring and carpet base, vinyl wall covering, wood doors with aluminum door frames, 2’ x 2’ recessed direct/indirect light fixtures and aluminum trim at the ceiling. Class AA floors employ upgraded carpet with enhanced base, enhanced wall coverings, frameless Glass doors and sidelights, indirect cove lighting and gypsum board ceilings with acoustic panel inserts.

Both Class A and AA toilet rooms feature granite lavatories and country club style toilet stalls with wood louvered doors. Class A toilet room walls utilize porcelain tile or thin-set stone tile on wet walls, vinyl wall covering on other wall surfaces, carpet at the lavatory areas and thin-set tile floors in the water closet areas. Class AA toilet rooms are upgraded to granite floors throughout with granite or porcelain tile on all walls. Class A buildings frequently utilize acoustic lay-in ceilings surrounded by gypsum board borders. AA toilet rooms incorporate recessed or architectural cove lighting within an articulated gypsum board ceiling.

Lease areas on the typical Class A office floors are designed for 9’ to 9’ 6” ceiling heights. Building standard ceiling tile and grids may vary, but 2’x2’ ceiling grid is most common. Class AA standards are upgraded to 10’ ceiling height with 2’x2’ Fineline 9/16’ wide grid utilizing tegular, beveled edge tile as the standard. 2x2 and 2x4 direct/indirect recessed light fixtures equipped with motion detectors are standard for both A and AA buildings. Sprinkler heads are semi-recessed chrome for Class A, fully concealed heads for AA.

Class A office space is typically cooled by self-contained package units which employ multiple compressors housed within a variable speed fan unit situated on each office floor. Heat is dissipated through a condenser water loop tied to a cooling tower located on the roof. Flexible after-hours cooling is favored by Class A tenants who can partially condition floors, on a zone by zone basis, utilizing condensers on an as needed basis. Conditioned air is distributed overhead through conventional perimeter loop and medium pressure interior loop. Fresh air is dehumidified by a central SCPU and distributed vertically through the core. Tenants using individual 24-hour air-conditioning units for spot loads can tap into the condenser water loop.

AA Class office buildings tend to operate on a more predictable time schedule and therefore may utilize a more efficient central chilled water system. Variable speed fans are served on each floor via a chilled water loop. Water-cooled chillers are linked to a condenser water loop and cooling tower located on the roof. Fresh air is dehumidified by a central fan and distributed vertically through the core. There are examples of new Class AA buildings using self-contained package units in lieu of water-cooled chillers.

Class A buildings attract tenants who populate their space at a ratio of one person per 300 to 325 GSF. Class AA tenants tend to be more sparsely populated with density based upon 350 to 375 GSF per person.

An Architectural Perspective: Office Buildings 2011 By Donald R. Powell, AIA

January 2011

Amenities and other IntangiblesOffice building occupants can effectively share a conference center, a deli, and a branch bank, but seldom are there population totals of sufficiency to support fine dining, shopping, fitness facilities, laundry services, a day care, a salon or day spa, entertainment or a hotel. A vibrant retail, restaurant and entertainment area situated within walking distance of the office building adds significant value to the office users. Class A and AA tenants must find suitable quality, variety and level of service in order to be of mutual benefit. Care must be taken to direct vehicular traffic to secured parking areas that serve the office users independently of the others on-site. It is possible to take advantage of countercyclical peak hour demands for parking and enhance the overall tenant experience.

An Architectural Perspective: Office Buildings 2011 By Donald R. Powell, AIA

January 2011