Skip to content
Chicago — Tier-1 Pillar

Chicago Insulation — R-49 Ceiling, R-21 Wall, Spray Foam, Vintage Retrofit

Chicago insulation reality. Chicago Building Code exceeds national IRC — R-49 ceiling, R-21 wall (or R-20+5 continuous), R-10 basement. Closed-cell spray foam for vintage brick retrofit, cellulose for attic blow-in. $3K-$16K typical.

~1 min read·Updated 2026-04-23

Chicago Building Code winterization requirements exceed IRC national minimums: R-49 ceiling (vs IRC R-38), R-21 wall (2x6) or R-20+5 continuous (2x4 + exterior foam), R-10 basement wall. Vintage brick retrofit typically uses closed-cell spray foam on the interior side of brick to control vapor drive and add R-value.

Frequently asked questions

Why is Chicago insulation stricter than national code? Cold climate zone 5. Chicago Building Code has been ahead of IRC national minimums for decades.

How much does Chicago insulation cost? Attic blow-in cellulose to R-49: $1.50-$3.00/sqft. Closed-cell spray foam retrofit on vintage brick: $4-$8/sqft. Typical whole-home retrofit: $6K-$22K.

<!-- STUB: content-sprint agent should expand to 1,200-word pillar. Add sections on: Chicago R-value code vs national IRC, closed-cell vs open-cell spray foam, cellulose vs fiberglass attic blow-in, vintage brick vapor-drive retrofit, typical whole-home scope. -->
Served in 62 neighborhoods

Where in chicago we match contractors

All neighborhoods →

Each neighborhood has distinct regulatory posture. Baily pre-scopes against the specific overlay your home sits under.

Talk to Baily about your Chicago project

Start a scoping conversation. Baily verifies every matched contractor against the specific licensing, insurance, and permit requirements that apply in Chicago before you get a quote.

Loading chat…

Origin

Who is Baily?

Baily is named after Francis Baily — an English stockbroker who retired at 51, became an astronomer, and in 1836 described something on the edge of a solar eclipse that nobody had properly articulated before: a string of bright beads of sunlight breaking through the valleys along the moon’s rim.

He wasn’t the first to see them. Edmond Halley saw them in 1715 and barely noticed. Baily’s contribution was clarity — describing exactly what was happening, in plain language, so vividly that the whole field of astronomy paid attention. The phenomenon is still called Baily’s beads.

That’s what we wanted our AI to do. Every inbound call and text has signal in it — a homeowner’s real question, a timeline, a budget, a hesitation that means “yes but.” Baily listens to every one, 24/7, and finds the beads of light.

Baily was a businessman before he was a scientist. That’s our vibe too.