BUILDING BASE STRUCTURES—WHAT IF YOU HAD TO START OVER?
- Worked on a retrofit last year where the client insisted on triple-pane windows. Their house was in a pretty mild zone, and honestly, the numbers didn’t justify the cost. We did a blower door test before and after—air leakage was barely improved because the rest of the envelope was leaky as a sieve.
- If I could start over, I’d always prioritize:
- Continuous insulation (even cheap EPS makes a difference)
- Air sealing—tape, gaskets, whatever you can manage
- Dealing with thermal bridges at framing, especially around headers and rim joists
- Triple-pane is great if you’ve already nailed everything else. Otherwise, it’s like putting racing tires on a rusty old sedan.
- On tracking bills: one client actually did this after swapping out double for triple. Savings were maybe 5% over a year—not nothing, but nowhere near what the window salesman promised.
- If budget’s tight, I’d put that money into better wall assembly or even mechanical ventilation before splurging on glass.
Just my two cents—seen too many folks get dazzled by specs and miss the basics.
BUILDING BASE STRUCTURES—WHAT IF YOU HAD TO START OVER?
Totally agree on the air sealing and thermal bridges—those are always the trouble spots people skip, then wonder why their heating bills are still high. I’d add that sequencing matters too. If you’re tearing things back to studs, I’d go: 1) detailed air barrier (tape, caulk, gaskets), 2) continuous insulation (even if it’s just a couple inches of EPS or mineral wool), then 3) address those rim joists and headers with rigid foam or spray. Windows are sexy, but they’re rarely the weak link unless you’ve got ancient single panes.
Curious—has anyone tried exterior air barriers vs interior? I’ve seen mixed results, especially in wetter climates...
BUILDING BASE STRUCTURES—WHAT IF YOU HAD TO START OVER?
Curious—has anyone tried exterior air barriers vs interior? I’ve seen mixed results, especially in wetter climates...
I’ve wrestled with this exact thing on my last project. Went with an exterior air barrier (taped sheathing) because I figured it’d be easier to get continuity, especially around all those weird framing intersections. In theory, it should keep the whole assembly drier, but honestly, in practice, it got tricky. The flashing details around windows and doors were a pain, and I was constantly worried about water getting behind the barrier and not being able to dry out. Maybe that’s just me overthinking it, but it made me second-guess the choice.
On the flip side, I helped a buddy do an interior air barrier with smart vapor retarder and gaskets. It was a lot more fiddly around outlets and plumbing, but at least you can see what you’re doing and fix leaks before you close up the walls. I guess the downside is you’re relying on drywallers to not mess up your careful work, which... yeah, good luck.
I keep hearing that in really wet climates, exterior barriers can trap moisture if you don’t get the flashing and drainage perfect. Anyone actually had long-term issues with that? Or is it mostly a matter of paying attention to the details? I’m still not sure which is less risky in the long run.
Also, on the sequencing thing, I totally agree—if you don’t get the air barrier right first, everything else is kind of a band-aid. But I’ve seen people obsess over windows and ignore the rim joists, like you said. Funny how the boring stuff is what really matters.
BUILDING BASE STRUCTURES—WHAT IF YOU HAD TO START OVER?
I’ll be blunt: exterior air barriers are only as good as your weakest detail, and in wet climates, that margin for error gets razor thin. I’ve seen projects where a single missed tape joint or sloppy window pan leads to rot within a couple years. People love the idea of “wrapping” the whole building, but unless you’re obsessive about sequencing and flashing, water will find its way in and just sit there.
Interior air barriers aren’t perfect either, but at least you can inspect and fix them before closing up. The catch is, like you said, you’re at the mercy of every trade that comes after—one careless electrician and your meticulous work is toast. Still, I’d rather patch a hole I can see than chase leaks behind siding.
If I had to start over in a wet climate? I’d double down on redundancy: robust exterior barrier with a rainscreen gap, AND a smart vapor retarder inside. Overkill? Maybe. But it’s way cheaper than tearing out moldy sheathing down the line. And yeah, rim joists get ignored way too often... that’s where half the problems start.
BUILDING BASE STRUCTURES—WHAT IF YOU HAD TO START OVER?
I get the urge to double up on barriers, but honestly, I think too much redundancy can backfire. I’ve seen high-end builds where over-layering just trapped moisture between barriers, especially when someone missed a detail or used the wrong tape. Instead, I’d focus on a single, bulletproof exterior system—fully integrated, with every penetration detailed like it’s a weak spot. Then, just keep the inside simple and let it dry to the interior if needed. Less to go wrong, and you’re not relying on trades to respect two separate systems. Rim joists, though—totally agree, those need special attention.