HEALTHY INTERIORS & MATERIAL SELECTION
What the house is made of is what you breathe.
Every other page in this section makes the building tighter. That is the right thing to do and it has one consequence nobody mentions: a well-sealed house holds onto whatever its finishes give off. The leaky house forgave bad material choices by diluting them with outdoor air all winter. A tight one does not. So the material specification stops being a decorating decision and becomes part of the mechanical system.
GREENGUARD vs GREENGUARD Gold
7× APART
The same brand. Plain GREENGUARD permits formaldehyde at 50 ppb — about 61 µg/m³. Gold caps it at 9 µg/m³.
"TSCA Title VI compliant"
MEANS LEGAL
Every composite wood product legally sold in the US already carries it. On a marketing sheet it is the floor, not an achievement.
What no label tests
SEMI-VOCs
Phthalates, flame retardants, metals, biocides. The certifications test what they test, and stop there.
What the labels actually mean
Four marks show up on almost every product sheet. They are not ranked versions of one another — they test different things, to different limits, for different categories.
What none of them cover
Every mark in this table measures volatile organic compounds in a chamber over a fixed period. None of them test semi-volatiles — phthalates, flame retardants — or metals, pesticides and biocides, which do not evaporate fast enough to show up in the test and do not leave the building either. A product can be perfectly certified and still be carrying something the certification was never looking for. That is not a reason to ignore the labels; it is a reason not to stop at them.
Frequently Asked Questions
Doesn't "zero-VOC paint" solve the paint question?
Not by itself. VOC content is a regulation about smog, measured in the can and written for air quality outdoors. What you breathe is emissions — what actually comes off the wall over the following weeks, which depends on the colourant added at the counter, the primer under it and the substrate behind it. A zero-VOC base tinted deeply is not a zero-VOC wall. Specify by tested emissions, not by the label on the lid.
Content is regulated outdoors; emissions are what you breathe
Is a tight house actually worse for air quality?
A tight house with no ventilation is worse than a leaky one, yes. A tight house with mechanical ventilation is far better than either, because you control the air rather than hoping the wind does. The leaky house only ventilated well on the coldest and windiest days, which is also when it cost the most to heat. Tight plus ventilated is the only combination that works.
Tight without an ERV is the one case to avoid
Is any of this measurable, or is it a vibe?
Measurable, and we would rather test than assert. Blower door for the envelope, measured ventilation rates at commissioning, and a post-occupancy air quality reading if you want one. What we will not do is claim a number for indoor air before the building exists — the product certifications describe products in a chamber, not your house with your furniture in it.
Blower door and measured flow at commissioning
How we sepecify an interior
WE SPECIFY
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GREENGUARD Gold or CDPH v1.2 tested where the category offers it
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Factory-finished over site-finished wherever it is an option
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Named adhesives and sealants, not "as required"
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Continuous mechanical ventilation, balanced and measured
WE CHECK
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The submittal, not the sales sheet — certifications by number
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Which tier of a certification, since the brands have several
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Cure and airing time before occupancy, written into the schedule
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Blower door and ventilation flow at commissioning
WHAT WE WON'T DO
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Treat a VOC-content claim as an emissions claim
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Call "CARB Phase 2" a selling point — it is the law
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Build tight without mechanical ventilation
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Promise an indoor air number before the building exists
A small building is the one where this shows up first.
Less air, more surface per occupant, and everything within a few feet of everything else. Send us the project and we will come back with a material schedule that names products and certifications rather than adjectives, and a ventilation design sized to go with it.