Lead-Safe Window Replacement in St. Louis: Why Windows Are the Exception in the Rule

If your house was built before 1978, replacing a window is a lead-safe job under federal law — every time, with no small-job exception — because the Renovation, Repair and Painting rule's minor-repair exemption applies only "where the work does not involve window replacement." That phrase is in the regulation (40 CFR 745.83). In a metro where 86% of the City's housing and 69% of the County's predates 1980, that makes most St. Louis window replacements RRP jobs, and it is the line on a quote that tells you whether the installer knows what they are doing.

Why are windows singled out?

Because windows are where lead paint is most likely to be, most likely to be worn into dust, and most disturbed by the work. Old window sash rub against painted jambs every time they open; the friction makes fine lead dust that settles on the sill and the floor below. Removing a window disturbs every painted surface around the opening — jambs, stops, sill, casing — and the old sash itself is usually painted inside and out. The EPA's minor-repair exemption lets a renovator skip the full rule for disturbances under six square feet per room inside or twenty square feet outside, but the definition adds: "where the work does not involve window replacement or demolition of painted surface areas." Window replacement is out of the exemption by name.

The EPA's own FAQ draws the line a little further: replacing a pane of glass or a broken balance "is not a window replacement," so those repairs can fall under the minor-repair limit if they stay under six square feet. Replacing the sash or the frame is replacement.

How much of St. Louis is pre-1978?

The Census counts year built in decades, so pre-1980 is the usable proxy:

U.S. Census Bureau, ACS 2020–2024 5-year, table B25034.

In practice: nearly every job in the City and the inner ring, most of North and South County, about half of Metro East, and one in four in St. Charles County. Florissant alone has more than 20,000 housing units built before 1980.

Who regulates it here?

The EPA, directly. Missouri's Department of Health and Senior Services licenses lead abatement professionals but states on its own page that Renovation, Repair and Painting is "Regulated by the U.S. EPA" and refers RRP questions to EPA Region 7. Illinois likewise has not adopted its own RRP program; the Illinois Department of Public Health licenses inspectors, risk assessors and abatement contractors, and RRP enforcement stays with EPA Region 5. Fifteen states run their own programs; Missouri and Illinois are not among them. So the credential to ask for on either side of the river is the same: an EPA Lead-Safe Certified Firm certificate for the company, and a certified renovator assigned to the job.

What a certified crew does differently on a window job

1. Pre-renovation notice. You receive the EPA's "Renovate Right" pamphlet and sign for it before work starts. (If you are a tenant, the owner and you both do.)
2. Testing or assumption. The renovator either tests the painted surfaces with an EPA-recognized test kit or assumes lead is present and works accordingly. On a 1920s brick house, assuming is the norm.
3. Containment. Plastic sheeting on the floor extending from the work area, interior doorways sealed, HVAC registers covered; outside, sheeting below the window and the ground covered to catch debris, with the area cordoned.
4. Work practices. No open-flame burning, no power sanding without HEPA, no dry scraping beyond the allowed area. Old sash and frame pieces are wrapped or bagged at the opening, not carried loose through the house.
5. Cleanup and verification. HEPA vacuuming, wet wiping, then the cleaning-verification wipe-and-compare procedure on the sill, the floor and the countertop within the work area. Records are kept for three years.

On a frame-wall insert job this adds perhaps twenty to forty minutes per opening; on a full-frame job in brick, more. We list it on the quote at roughly $40–$120 per opening, depending on method. It is not optional and it is not a profit line; it is the law and it is the thing that keeps lead dust off a toddler's hands.

What to ask any installer

• "Is your company an EPA Lead-Safe Certified Firm? Can I see the certificate?"
• "Who is the certified renovator who will be on site?"
• "Where on this quote is the lead-safe work?" (If the answer is "we don't need that for windows," end the conversation.)
• "How do you dispose of the old sash?"
• "Will you do the cleaning verification before you leave?"

What it does not cover

RRP is about doing the renovation safely. It is not lead abatement, which is a separate licensed activity under Missouri DHSS and Illinois IDPH aimed at permanently removing the hazard. If a child in the house has an elevated blood lead level, the City's Building Division and the health departments run inspection and remediation programs that go well beyond a window job. The City of St. Louis publishes its childhood lead-poisoning data and resources; we link to the City rather than summarize numbers we cannot keep current.

Frequently asked questions

My house is 1965 in Florissant. Does this apply? Yes. Any housing built before 1978, unless it has been certified lead-free by a licensed inspector.

What if I do the work myself? The RRP rule applies to firms and contractors working for compensation; an owner-occupant doing their own work is not covered by it. The dust is the same.

Does lead-safe work mean the old windows are "hazardous waste"? Old sash and frame pieces are bagged or wrapped at the opening and disposed of as construction debris. We do not leave it on the curb loose.

Does the rule apply to the exterior only? No — inside and outside the opening.

Is a certified firm more expensive? The containment time is real; the rest of the quote is the same. An uncertified firm quoting lower on a 1920s house is quoting a job they are not permitted to do.

Next step

Window replacement and full-frame replacement both list lead-safe work as a line item on every pre-1978 house. Related: the brick guide · the complete St. Louis guide.