You may hear the words “clear heights” and “maximizing cubic value vs. square footage” and your brain starts to slowly turn off, but in my line of work, this is an area I feel fiercely passionate about, much to my wife’s chagrin. I continue to hear from clients who are being told by partners or consultants to construct taller and taller industrial buildings, without vetted data and worse, that are not relevant to their needs.
It becomes a matter of what they think is needed, which often leads to over building resulting in underutilized and wasted vertical space that directly impacts the bottom-line costs of constructing and operating the facility. It’s more steel, more precast, more conditioned space, all unnecessary expenses. My goal, and the goal of my firm, is to provide clients with the best value and design solutions, especially when it comes to industrial, manufacturing and distribution design.
Building a 'right-sized' building has a life cycle cost and economic benefit to a company. If we can unpack the decision method for clear height rather than responding to unvetted suggestions, it benefits all types of industrial projects from speculative development to build-to-suit projects. So how do you maximize size?
To clarify, the “clear height” is the lowest structural or mechanical obstruction above the finished floor. We also use the term “ceiling,” which in many buildings is the exposed deck that is above the joist or beam structure.
Start by Understanding Use
To get to the best height, we need to work backwards, understanding the key components within the building from material handling, to racking system to pallet height.
When starting to determine programming and in turn building dimensions, one of the first questions I ask clients is, "How many pallet spaces do you have?" By understanding this and the corresponding dimensions first and backing it in, we can right-size the warehouse component of the building.
Each business has their own pallet system with requirements and dimensions that will factor into the ideal clear height for your facility. But for our purposes today we’ll use a standard 64” tall pallet, a relatively common dimension used by about half the market.
It’s also important to understand the material handling equipment used within the facility, as well as any future technology advances and the desired investment level. For starters, forklift style, from the most basic and lowest cost conventional forklifts to narrow aisle forklifts or very narrow aisle forklifts will influence the programming and layout of the space, the high-density rack system purchased, automated storage system and in turn, the ideal building clear height and design.
Finally, the sprinkler systems will also influence programming and building dimensions of the ‘clear height’, as the prominent selection of ESFR (Early Suppression Fast Response) sprinkler system requires 12”- 18" distance from the ceiling (deck) and 36” above stored material. While the compounding inches of 48”- 54” sounds like a lot, it accommodates for the typical roof structure, which is also a depth of 48” – 54".
By understanding how all these factors come together, we can develop a program for build-to-suit or speculative development that meets current and future needs as well as attracts prospective tenants.
Clear height to standard pallet sizes. 64” pallet package is the most common.
Busting the 40 Foot Myth
I fully understand that regionalism plays a factor in the ideal vertical height. The current trend in the market is a push for taller buildings, but I question if this extra volume is being utilized. Understanding your city tier can influence vertical height decisions. Today, in the Chicago market for example, if you don't have 40' clear height on a speculative property, then you've essentially built a white elephant. But is this really the right solution? If you look at the way the racking systems are designed as well as the standard 64" tall, packed pallet against the modular of 40' the divisibility is off. Let’s break it down: for each pallet you basically need 72" clear height to accommodate material handling needs. Taking 72” (6’) divided by 40’ is 6.66’, so we are in essence designing buildings that are 8" too tall. Eight inches doesn't sound like a lot in the grand scheme of things, but when you think of 8" over 500K sq ft to 1.5M sq ft, resulting in 333,000 cubic ft – 1,000,000 cubic ft of wasted space, which is an actual cost. As a reference, we recently worked with a client in Madison, Wisconsin, a tier-three city, on a 180,000 sq ft building, and due to tenant equipment requirements we determined the ideal vertical height was 32’.
Optimizing Vertical Height and ROI
So, does it make sense to dig into the numbers to get to an ideal height or just go with the standard 40’? Some considerations are the building materials to create the excess height, the operational costs to heat/cool the space, and if buildings get high enough (over 40’ tall) it can require a propriety sprinkler system, reducing the ability to do competitive bidding on this component. The larger the building, the higher these costs become.
NAIOP has teamed with western US based HPA Architects on the second edition of “Rules of Thumb for Distribution/Warehouse Facilities Design,” providing the recommendations below.
- Buildings below 50,000 sq ft can be 28-ft
- Buildings between 50,000 sq ft and 80,000 sq ft can be 30-ft
- Buildings between 80,000 sq ft and 150,000 sq ft should be 32-ft
- Buildings between 150,000 sq ft and 500,000 sq ft should be 36-ft
- Buildings above 500,000 sq ft and (cross-docked buildings) should be 40-ft or 42-ft
These are good baseline numbers, but it is still important to dig into the use and considerations discussed above, and to understand local markets.
Clear Height Examples
This topic inspired me to look back at some of the recent industrial projects (primarily in the Midwest) that we have completed and what the clear heights have been. As you will see the buildings below do not follow the rules of thumb above, but were developed in response to the pallet heights and racking system to work for the specific client needs.
- Building, 130,000 sq ft, Waukesha, WI, 24’ clear
- Building, 137,000 sq ft, Madison area, WI, 28’ Clear
- Building, 156,000 sq ft, Waukesha, WI, 28’ clear
- Building, 184,000 sq ft, Madison area, WI, 28’ clear
- Build-to-suit Manufacturing, 94,000 sq ft, Madison, WI, 29’ Clear
- Build-to-suit Distribution Center, 642,800 sq ft, Kenosha WI, 33.2’ Clear
- Build-to-suit Distribution Center, 936,200 sq ft, Naples, FL, 41’ Clear
- Build-to-suit Distribution Center, 1,012,000 sq ft, Pleasant Prairie WI, 36’ Clear
- Build-to-suit Distribution Center, 1,087,520 sq ft, Kenosha WI, 35.4’ Clear
I want to make it clear that I am not an anti-height industrial architect – so when is maximizing vertical height essential? With many greenfield sites, buildings can be built with a larger floor area, reducing the drive for vertical height, but in urban settings or when challenging site constraints arise, vertical height becomes an essential part of the ROI equation. The examples above are all greenfield sites, allowing for a larger floor area and reduced clear height.
So, there you have it, an exciting topic with a lot of numbers and figures about how to get to the ideal clear height for your facility. Just know that this comes from a place of passion, I am committed to helping my clients build the optimum facility while avoiding being a white elephant in their marketplace. Are you wondering what clear height is best for your facility? Give me a call; I will ask some questions and we can crunch some numbers together.
Chris Johns, AIA
Senior Project Manager : Industrial Market Leader : Associate