As a court planner, I often must explain my programming approach when determining the size of a courthouse. Courthouses are inefficient buildings, and this is intentional. Therefore, it is not possible to calculate the size of a courthouse the same way as an office building.
In this blog, I will explain why courthouses are inefficient, and I will provide what I believe is the best method for estimating the overall size of a courthouse.
Building Efficiency Factor
First, I’ll explain what I mean by a building’s “efficiency factor.” Efficiency in real estate is measured by the ratio of Usable Square Footage (USF) to Building Gross Square Footage (BGSF). USF is the space occupied by tenants. BGSF is the total square footage of a building, which includes the USF plus the square footage attributed to the core spaces such as building circulation, public areas, restrooms, elevators, exit stairs, spaces that house the building systems, and the exterior walls.
For simplicity, let’s think about it in terms of a typical office building. Suppose a building contains a high percentage of USF when compared to the BGSF. The building would be considered to be efficient. Obviously, a building with a lower percentage of USF would be considered inefficient.
This is important to building owners. It enables them to optimize their rental revenue instead of paying for core spaces that only exist to support the operation of the building. Typically, developers strive for a building that is approximately 70-75% efficient. This means 70-75% of the building will be available for tenant space. However, establishing the BGSF of a courthouse based upon an efficiency factor of 70-75% will result in an underestimated project size.
I recently took part in a courthouse project. The size and budget of the courthouse were based on the typical efficiency factor of 75%. Even though we advised our client upfront that the project was undersized and, therefore, the budget most likely too low, the owner insisted the efficiency factor was accurate and directed us to move forward.
As we progressed to concept design, it became apparent that the courthouse would not achieve such high efficiency. It is never pleasant to tell an owner that the budget is too low. Fortunately, the owner finally accepted the news and secured more funding for the project, but that is not always the case. An undersized program can cause significant delays in a project.
Courthouse Efficiency Factor
I have found that an efficiency factor of 65% is the most appropriate to apply when programming a courthouse. Applying a 65% USF/BGSF ratio has consistently resulted in the programmed BGSF being within +/- 5% of the actual designed BGSF at the schematic design phase. This figure typically tightens up as the massing of the building and types of mechanical systems become more defined during design development.
Here are the leading causes that make 65% a more appropriate efficiency factor when planning a courthouse:
Three separate circulation paths
This is probably the biggest culprit contributing to a courthouse’s inefficiency. A courthouse requires separate circulation paths for detainee movement, judges’ circulation, and the public. If any of these paths cross, it is a significant security concern, so designing a building to accommodate the increased circulation space reduces the amount of available USF for tenant spaces.
Somewhat related to circulation, several areas in a courthouse require wider corridors. For secure detainee movement, an 8’-0” wide corridor is recommended as it must simultaneously accommodate the detainee and law enforcement (typically two officers per detainee). In some courthouses – particularly renovations - the path for detainee movement can also be quite circuitous to maintain separation from the other circulation paths. Additionally, corridors outside a courtroom are typically wider – up to 15’-0” - to accommodate the higher occupancy load of a courtroom and provide a comfortable public waiting area.
Often courthouses are designed with larger spaces, such as an atrium or enlarged lobby, to accommodate civic functions. I have been involved with several court planning efforts where the goal was for the building to become more welcoming to the public, and extra space was required in the lobby to accommodate after-hours functions such as art shows or lectures.
How To Apply the Building Efficiency Factor
To establish the BGSF for a new courthouse, the total programmed USF should be divided by the building’s estimated efficiency (USF/Efficiency Factor).
Let’s look at an example:
You are programming an office building. The goal is to achieve 75% efficiency, and you’ve determined that the building will have 100,000 USF. The estimated BSGF for that building would be 133,333 GSF (100,000/.75).
The BGSF for a courthouse with the same USF would be 153,846 GSF utilizing a 65% building efficiency factor. This will accommodate the circulation patterns and civic spaces described above.
A common programming practice is applying a multiplier of 25-35% (1.25-1.35) to account for circulation and walls within a department. Such a multiplier is typically applied to the Net Square Footage of a department to obtain its USF.
Do not mistake an efficiency factor for being a multiplier to be applied to the USF. Doing so will result in a building that is too large! Because the factor represents the ratio of USF to BGSF, the USF should be DIVIDED by the efficiency factor (e.g., USF/.65= BGSF).
Understanding the justification for a lower efficiency factor for courthouses is a key component of programming a new courthouse. Applying the appropriate efficiency factor for a courthouse, as opposed to a typical office building, allows for a realistic estimate of the project size and will be beneficial to keeping the project on track.