The town I live in — Berkeley, Calif. — is the capital of shaggy wooden houses. Around here, you could get stoned for saying you don’t like natural wood exteriors. So I won’t say that. But what 30 years of practicing architecture have taught me is this: Natural wood is a fabulous finish inside a house, where it’s protected. But as an exterior wall finish, left to the elements? Forget it.
The reason exposed wood — whether left natural or given a transparent finish — is still so popular on building exteriors is that it looks absolutely stunning when it’s new. That’s exactly how most people see it in tony design-magazine photos, and so that’s how they think it will look on their own homes. Alas, the reality is that, after a few years, wood is on a one-way trip to "Shabbyville."
I can paraphrase the lumber industry’s stock reply to this assertion, and it goes something like this: "A premium material such as wood needs proper maintenance to keep its beauty, and anyone willing to invest in genuine wood should also be prepared to keep it maintained in top condition."
The trouble is, over time — after the initial 10-year honeymoon, let’s say — very few people continue to provide the kind of painstaking maintenance that’s required to protect natural wood subjected to the weather. And once that maintenance level has slipped even a little, a wood exterior is already on track to inevitable decline.
Compounding this problem: The quality of solid lumber in general has declined during the last few decades. Therefore, unless you’re prepared to pay astronomical prices for carriage-trade grades of lumber, a new wood installation will have an even shorter life span than in the past.
Contrast the ongoing maintenance headache of natural wood with the nominal attention required by that longtime bad boy of building finishes, stucco. Over the last 60 years, stucco’s good reputation has been sullied by lookalike mid-century housing tracts such a Levittown, not to mention Malvina Reynolds singing about "little boxes made of ticky-tacky."
Yet stucco is both cheaper and far more durable than wood. It’s also "plastic" in the best architectural sense — it can assume just about any form you can imagine. It can also be permanently colored, doing away with the need to repaint every few years. An exterior finish that can hold up for a century or so with practically no maintenance — not even painting — is about as good as it gets.
As an architect, I’ve learned that it’s pure folly to specify fragile finishes and then expect people to maintain them forever after. Nor should a homeowner be condemned to this kind of maintenance schedule, no matter how beautiful the finish.
So I almost never use natural wood on exteriors. There are exceptions — if the timbers are substantial enough, for example, wood can’t be beat for outdoor structures such as pergolas and the like. But for an architecturally interesting finish that’ll last pretty much forever, I’ll take ticky-tacky anytime.