How to Find an MCS-Safe Contractor

The Core Problem

There is no licensing category for "MCS-safe contractor." No state issues a chemical sensitivity construction license. No trade school teaches it. When families with chemical sensitivity search for a qualified contractor, they are searching for something the industry has not defined.

This creates two problems. First, families cannot find contractors by searching a category that does not exist. Second, contractors who could do this work — and do it well — do not know they are qualified because no one has given them a specification to follow.

The Good Air Standard solves both problems: it gives homeowners a specification to hand contractors, and it gives contractors a clear standard to follow. The question is not "do you specialize in MCS construction?" The question is "will you follow this specification?"

What to Screen For

Willingness Over Specialty

A general contractor with 15 years of residential experience who is willing to follow a material specification, isolate the HVAC during finishing, and allow air quality verification is a better candidate than a self-described "green builder" who resists being told what products to use. Willingness to follow a defined process matters more than marketing language about healthy homes.

The 12-Question Test

The Builder Interview Script covers four areas:

• Material compliance: Will you follow a material specification I provide? Will you notify me before substituting any specified material? Will you provide documentation of what was actually installed?
• Moisture management: How do you handle framing that gets wet during construction? What is your approach to drying before enclosing? Can you describe your flashing details?
• Construction-phase air quality: Will you seal HVAC registers before coating and finishing work? Will you set up directed exhaust during the cure period? Have you done this before, or are you willing to follow a protocol for the first time?
• Verification: Will you allow a pre-occupancy air quality reading? Will you provide a written log of materials used on the project?

Red Flags

These responses during the interview indicate a contractor who is unlikely to execute to the standard:

• "We already use low-VOC everything" without being able to name specific products or provide documentation. "Low-VOC" is a regulatory floor, not a specification.
• "We'll just ventilate" as the entire air quality strategy. Ventilation without direction spreads emissions deeper into the building. This is the most common failure mode.
• Resistance to HVAC isolation: "We've never needed to do that." The HVAC system running during coating work is the single most common cause of lasting duct contamination.
• Resistance to material documentation: "We'll use whatever meets code." Code compliance is the floor, not the standard. A contractor unwilling to document material selections will not follow a material specification.
• "Trust me, I've been doing this for 20 years": Experience is valuable. Experience that resists a written process is not.

Green Flags

Indicators of a contractor who will execute well:

• Asks clarifying questions about the specification rather than dismissing it.
• Has experience with moisture management beyond "we dry it out." Can describe flashing, drainage planes, and drying strategy.
• Willing to do something for the first time — HVAC isolation, directed exhaust, air quality verification — if given clear instructions. Willingness to learn is more valuable than claimed expertise.
• Provides references from detail-oriented clients, not just "we got five stars."

The Spec Pack Approach

The most effective way to work with a contractor who has not built for chemical sensitivity before is to provide a written specification — not a conversation about preferences. The $79 Build Package includes option-specific contractor spec packs that document material requirements, the Clean Air Construction Protocol, and verification steps. The contractor bids against the spec. Ambiguity is reduced. Expectations are documented.

This changes the dynamic from "homeowner asking for special treatment" to "homeowner providing a professional specification." Contractors respond better to specifications than requests.

Good Air Certified Builders

The Good Air Standard is building a network of certified builders who have passed 10 verification gates — from licensing and insurance through Good Air Standard knowledge, material compliance commitment, Clean Air Construction Protocol capability, and documented project verification. Certified builders have already been screened against the criteria above.

If no certified builder is available in your area, the Builder Interview Script and spec packs allow you to screen and equip any qualified general contractor to work to the standard.

What Not to Do

• Do not rely on "green" or "healthy home" marketing alone. These terms are unregulated and mean different things to different companies. Screen against a specification, not a brand promise.
• Do not assume a contractor who built one healthy home can build another without a specification. What they did on that project may not match what you need on yours.
• Do not skip the HVAC isolation question. A contractor who will not seal registers before finishing work will contaminate the duct system. This is the single most common lasting failure in remodeling for sensitive occupants.

Evidence Basis

Contractor screening criteria adapted from SMACNA IAQ Guidelines for Occupied Buildings Under Construction, ASHRAE Guideline 1.4 (IAQ Procedure for commissioning), and Good Air Homes 10-gate builder verification framework. HVAC contamination data from EPA research on particulate and VOC deposition in duct systems during construction activities. Spec pack methodology follows CSI MasterFormat principles adapted for residential IAQ applications.