Editor’s note: This is Part 3 of a three-part series. Read Part 1 and Part 2.

Last time, we looked at some building code requirements that routinely trip up do-it-yourselfers. As arcane as some of the code’s provisions might seem, practically every one of them exists to ensure health and safety, and many were gleaned from over a century of knowledge hard won from real-life incidents, many of them both tragic and unnecessary.

Because building codes — and this includes plumbing, mechanical, electrical and fire codes — are primarily concerned with health and safety, they’re by nature conservative and slow to change.

There’s little incentive for the councils who collectively author the various codes to adopt new technologies that make construction cheaper, faster or more efficient, since these things aren’t directly related to safety. Hence, the code generally ignores technical innovations until there’s overwhelming pressure from the trades, the design professions or manufacturers to incorporate them.

There’s no doubt that this conservatism sometimes impedes the adoption of worthwhile new products. For example, plumbing codes were slow to approve ABS plastic drain piping even though its advantages — low cost, lightweight, excellent durability, and ease of assembly — clearly outweighed its shortcomings (noisiness and susceptibility to fire).

In fairness, plastic plumbing also encountered some resistance from plumbers, many of whom were not keen on seeing a do-it-yourself-friendly material infringe on their business. The various metallic pipe industries, who saw a fair share of their markets about to go down the drain, were not too keen on plastic either. Still, the overwhelming advantages of ABS eventually forced the code to make room for it, and later on for other plastic plumbing materials as well.

More recently, a simple plumbing device called an "air admittance valve," or AAV, has made it possible to greatly simplify the venting portion of drainage systems, eliminating perhaps one-third of the drain piping in a typical house. AAVs have been used in Europe since 1979, and with several million installed they’re well proven.

Yet until very recently, plumbing codes in the U.S. continued to insist that plumbing fixtures be vented through the roof, just as they have been since Victorian times — a needless waste of expensive labor and material, and a common source of roof leaks. Only in the last few years have most plumbing codes finally approved AAVs, and even at that, a few individual state codes still stubbornly outlaw them.

On another front, building codes have shown a sometimes overzealous tendency toward protecting people from themselves, often at a significant cost to comfort and aesthetics. A clear example is found in the code’s ever more stringent requirements for residential railings.

The allowable open space between rail balusters, for example, has progressively shrunken from 9 inches to 6 inches to 4 inches, while the minimum height of exterior railings has recently increased from the longtime standard of 36 inches to a towering, view-obscuring 42 inches.

Still, these are minor quibbles about a document that do-it-yourselfers ought to welcome as more help than hindrance. The building code is like a crotchety old neighbor who’s seen it all during his lifetime — his advice might grate on us now and then, but we’re still glad he’s around when we need him.


What’s your opinion? Leave your comments below or send a letter to the editor. To contact the writer, click the byline at the top of the story.

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