DESIGN BASICS FOR MULTI-TENANT OFFICE BUILDING TENANT IMPROVEMENTS





Office space design is more about creativity than technical complexity. The technical aspects – the constructability and code issues - of designing tenant spaces in office buildings are relatively simple compared to most types of projects. Yet, office tenant improvements are a specialized niche that many architects can easily fumble if they do not have experience in it. Much of my 30-year career has been in designing office tenant improvements.


With tenant improvements, the architect often has two clients, the landlord and the tenant who is leasing space in the landlord’s building. Each of these clients may have conflicting goals. With a typical 5-year lease, most landlords want their space designed so that it is generic enough to easily accommodate the next tenant with little re-work. Yet most tenants want a space that is unique to their functional needs and sets them apart. The architect must often diplomatically negotiate these two differing interests.


A savvy landlord will have building standards, developed with the assistance of an architect, which outline the products that shall be utilized within the space. The specifications of the suspended acoustical ceiling system, light fixtures, doors, door hardware, interior window frames, and window treatments are pre-determined by the standards. The landlord must maintain a space, and it would be inefficient to stock 20 different types of replacement light fixtures and bulbs (known as “lamps”) for 20 different tenants.


Interior partitions or walls will generally stop at the ceiling so that the ceiling grid is not broken and does not require replacement as walls need to be relocated for new tenants. Even the direction of the ceiling grid is pre-determined so that as walls are moved, the ceilings throughout the floor still align. This approach means that acoustical privacy between rooms must be addressed with batt insulation or vertical sound blankets above walls in the crawl space. Moreover, light fixtures, which lay in the ceiling grid system, will not be centered in each room as is the ideal because the ceiling grids are not centered in each room. Yet, this approach reduces the cost of relocating walls for the needs of future tenants, although light fixtures, HVAC vents, and sprinkler heads within the ceiling must still be relocated when wall locations change. Additionally, the carpet must be replaced and adjacent wall surfaces patched as demolished walls leave scars in the flooring material and adjacent walls, even if not in the ceiling.


Architects unfamiliar with multi-tenant office building standards might design the interior partitions so they go through the ceiling to the slab above, center the ceiling grid and light fixtures in each room, specify specialized light fixtures, vary the ceiling heights for specialty areas, design drywall ceilings and soffits, clerestory windows in interior partitions, floor tile, and more. These are typical features in many stand-alone projects, yet not in multi-tenant office buildings where uniformity is key. Once an architect is familiar with a building’s standards, the design process will be relatively simple compared to other types of projects. However, often, landlords will not enforce the building standards if the financials of a lease deal make it worthwhile, although that is usually only the case for large tenants leasing at least 20,000 or more square feet.


What do most tenants have a say in? They’ll usually get to choose the carpet and paint colors. Since most carpet only lasts about 5 years, and paint is cheap, landlords expect to change these items between tenants. Most important, however, the tenants, with the help of an architect, typically drive the space layout so that it meets their functional needs. This brings us to a discussion on space planning.


Space planning in office buildings is, again, relatively simple compared to most projects. Most office buildings have a number of suites along the outside perimeter of a building off a fire-rated corridor that leads to two-fire rated stairwells on the opposite side of each floor. The corridor and stairwells are part of the building “core” which also includes the elevator shafts, elevator lobby restrooms, and mechanical and electrical rooms on each floor.


Many corridors are a Z-shape, and many make a complete loop around the core. On floors that have only one single tenant, a corridor may not be needed at all. The boundaries of the corridor are usually pre-determined. If the corridor must be shortened or lengthened to accommodate a new suite entry or exit door, there are a few considerations. The corridor must, at a minimum, connect the two stairwell doors which will be on opposite corners of the building core. And, in general, cannot extend further than 50 feet past the stairwell door on either end, a condition called a “dead-end corridor,” unless it makes a complete loop.


The boundaries of a tenant space are also, more times than not, pre-determined. Yet it is also a common need to change the demising wall locations between separate suites or combine two or three suites into one. When doing so, exiting codes must be examined. A suite over 50 occupants requires two exits. Calculating the occupancy of a suite is beyond the scope of this article, but this generally equates to a suite that is about 4,000 square feet give-or-take a couple hundred square feet. When two exits are required, they must be a certain distance apart from one another, so that all of the occupants of a suite do not rush towards the same area in the event of an emergency. The required distance between exits differs depending on whether the building is sprinklered or not. This requirement is sometimes difficult to achieve based on the configuration of the corridor. If the corridor cannot be modified, and the distance between exits is impossible to achieve, then the size of the suite must be reduced. Alternatively, a suite can sometimes be divided into two suites with a fire-rated wall between them and “communicating” doors connecting them so that they can be occupied by the same tenant. However, this is usually not conducive to a tenant’s space needs. Luckily, due to proper corridor design, it is rare that the exiting requirement cannot be met for a suite. When it does occur, it is usually at suites located at the ends of the corridor where only one suite entry door is possible. Within the suite itself, it’s also not allowable to have “dead end” hallways of a certain length, or having to go from room to room to room to exit.


It's important for landlords and tenants to hire an architect who has extensive experience designing interiors in multi-tenant office buildings. Many building architects think of themselves as problem solvers who can design any type of project, however, the fees are typically relatively low on office tenant improvements and an architect that’s experienced in them will typically charge three times less than the architect who isn’t. In my experience, architects who don’t have extensive experience in this project type will tend to overcomplicate the project, which results in a longer schedule to complete their work, but also in higher construction costs.