• Cyburbia is a friendly big tent, where we share our experiences and thoughts about urban planning practice, the built environment, planning adjacent topics, and anything else that comes to mind. No ads, no spam, and it's free. It's easy to join!

WTF ⁉️ Local code amendment WTFs: prohibitions on "mainstream-alternative" building methods

UrbanUnPlanner

Cyburbian
Messages
47
Points
2
One thing that I have noticed in my research over a span of years now is that local building code amendment packages tend to be less competently drafted and conceptualized than the North American national model building codes (IBC, IRC, UPC or IPC, IMC, IFGC or NFGC, NEC). This isn't nearly as much an issue in major jurisdictions or for statewide codes, as they have enough resources to hire subject-matter experts (trade veterans and PEs) to handle such, but in smaller jurisdictions, it's very easy for the task to be left to someone who isn't a building-code expert, and the results can be rather baffling.

An example of this that I came across recently during some unrelated research is Prospect Heights, IL. This seemingly-ordinary Chicago suburb imposes a rather...provincial and backwards set of requirements on residential construction:

  • Insulating Concrete Forms and Structural Insulated Panels are completely forbidden for residential work. This makes me wonder what they'd do if someone built a house using precast concrete technology or even standard cast-in-place/tilt-slab techniques?
  • They require 16" or closer stud spacing and double top plates. This prohibits the Advanced Framing package with its 2x6 studs on 24" centers, single top plates, and fully in-line, continuous-load-path framing.
  • They prohibit balloon framing, which isn't an issue for wood construction but effectively prohibits the use of cold-formed steel for single-family work outside of single-story structures. (I wonder if they'd try to enforce stud spacing and top plate requirements for cold-formed steel construction?)
  • They require all wood framing members to be dimensional lumber. No TJIs/I-joists, no LVL/PSL beams, and no other forms of engineered wood member. This has me wondering if they would accept wooden truss joists, even?
  • They prescribe plywood for roof and floor sheathing and plywood or OSB for wall sheathing. This effectively prohibits foam sheathing or hybrid products (such as Zip-R), as well as inadvertently prohibiting the use of noncombustible structural sheathings (cement-bonded structural particle/fiber boards, magnesium oxide structural sheathing boards).
  • They beefed up their fire-separation requirements for attached garages (fine by me) but did it with a strict prescriptive callout for Type X drywall, including requiring a double layer of the stuff on the ceiling if habitable space is above the garage. This effectively shows no respect to builders who want to use a tested and listed fire-rated assembly for house/garage separation purposes instead of relying on drywall alone.
  • They require site-poured concrete for all foundation walls. This not only prohibits masonry/concrete block foundations, but ICF (of course), precast (why?), pier-and-curtain foundations (I can see why one would do this, at least), and probably novel foundation technologies too (such as helical piles or slurrywalls)
  • They prohibit wet venting of plumbing fixtures in single-family construction (why? Illinois plumbing code has no problem with it, and they don't amend out that part of the plumbing code for commercial or multi-family work)
  • They also call out specific materials and techniques for roof underlayment, which aren't always applicable (fluid applied underlayments are a thing these days...)
  • And last but not least, they appear to have set their local ordinance up so that their local prescriptive amendments override the model Code equivalency provisions, effectively tying the hands of their own building officials, at least as far as I can tell...

What's more, their commercial/multifamily construction requirements have a few WTFs of their own atop being relatively onerous: they require fully noncombustible or fire-resistive construction (IBC Type I/II), and prohibit the use of fire-retardant-treated wood for structural members, but this is neither a total WTF nor as total a barrier to newfangled things as they think: some composite-type ICF systems ("grey block" as they are sometimes called) are essentially non-combustible on their own (vs foam which'll char and smoke, but not propagate the fire).

However, they also require 2 hour rated (minimum) CMU demising and corridor walls for condominiums, only allowing gypsum board if CMU walls are impractical. This is strange not only because it calls out CMUs specifically, it's a construction requirement that's particular to condominiums -- multi-tenant rental buildings aren't required to be built this way! They also require 16" stud spacing and 5/8" Type X drywall for partitions, and require master water metering of condominium buildings, just to add to the pile of head-scratchers already here. (Note that I left out electrical: Cook County standard electrical code is a whole another matter entirely, but it's something that is respectable despite its onerousness, unlike many of the WTF-amendments I have posted here.)

Is there a reason that they'd be making their lives and the life of every builder who wants to work in their jurisdiction harder, while at the same time prohibiting alternative techniques and practices that are used to good effect in the rest of this country to make houses that can quite readily argued to be superior to minimum Code performance levels? Have any of my fellow Cyburbians run into these sorts of prohibitions and overprescriptions that effectively prohibit "mainstream alternative" construction in jurisdictions they've researched or been involved with? (Note I'm not talking about way-out-there stuff like earth-sheltered houses, cob or straw-bale construction, or other such things that aren't used across a broad spectrum of geographies and uses, but ICF and SIP are mainstream enough to be used for a wide variety of buildings across the nation, including hotels and public schools, and cold-formed steel structural systems are commonplace in commercial work as well.)
 
  • Like
Reactions: Dan

mendelman

Unfrozen Caveman Planner
Staff member
Moderator
Messages
15,937
Points
60
In my 19+ years of diversified experience in development review and building code enforcement/processes adjacency, I'd say there may be a mix of purpose and accident to your example.

I've developed into a zoning and land use regulatory expert in my career and have developed the guiding philosophies of "create the most benefit to all involved parties" and "find solutions, not obstacles."

There may be a simple answer of administrative inertia (add regs, but can't let go of 'old' regs) and/or direct desire by the legislative body to create a certain gatekeeping and/or revenue generator through permit administration.

I actually have a fair amount of on the ground knowledge of Prospect Heights, IL, so your specific analysis of their building code is further illuminating for me.
 
Last edited:

DVD

Cyburbian
Messages
15,628
Points
53
It could be a hundred things. My city doesn't change anything quickly so lots of old remnant codes get left in there. We tend to treat codes like that as only if you're doing this specific thing if not we ignore it. We're easier on building code, we just adopt IBC code books. We do amend things like fire sprinklers though. We require them in damn near everything except a house. TND requires them in new houses. Let's just say we've got some good ISO ratings around here.
 

UrbanUnPlanner

Cyburbian
Messages
47
Points
2
There may be a simple answer of administrative inertia (add regs, but can't let go of 'old' regs) and/or direct desire by the legislative body to create a certain gatekeeping and/or revenue generator through permit administration.
I think your "gatekeeping" theory might have something to do with it, as protection for a "chosen" set of local homebuilders over those mad scientists from out-of-town who want to run crazy experiments on folks' houses, like sealing them up tight and then using a fancy heat exchanger to bring in ventilation air anyway. (Turns out, ventilation works better when you have a handle on what you're bringing in and can precondition it appropriately.) The alternative I see is that perhaps the building department there simply has no desire to learn how to inspect such newfangled things as ICFs or advanced framing? (Both of which are quite mature technologies at this point in time -- the latter comes from the Optimum Value Engineering research done by HUD & NAHB back in the late 1970s, even.)
I actually have a fair amount of on the ground knowledge of Prospect Heights, IL, so your specific analysis of their building code is further illuminating for me.
Perhaps you can share some of the points you came to? I'm curious as if they'd enlighten me as to which of the above theories, if either, might be driving the bus on such an unusual set of local amendments.

We do amend things like fire sprinklers though. We require them in damn near everything except a house. TND requires them in new houses. Let's just say we've got some good ISO ratings around here.
It utterly baffles me how folks can spring for granite countertops and high-end appliances, yet hide their wallets in terror when asked to add $1-$2/sf to the cost of their house for the best fire insurance money can buy. Is there some sort of gross marketing failure at work here, or just what is going through people's heads to make them act in such a way?
 

DVD

Cyburbian
Messages
15,628
Points
53
I talked to a guy buying land for his new home. One was a nice couple acres where he just needed a building permit. No big deal. The other was a couple acres in the floodplain. I literally told him I will abuse the crap out of you with permits for this one. He bought the floodplain land. It was cheaper. Not for long...
 
Top