Insulation in Pacific, Missouri

Insulation and air sealing in Pacific

Pacific runs to about 6.7 square miles and roughly 7,414 people. It sits about 30 miles southwest of downtown St. Louis. There are around 3,218 housing units here. The community dates back to 1859. We cover ZIP code 63069.

We have not logged a completed job in Pacific yet. We would rather say so than put a number on this page that is not real.

The housing stock in Pacific

The typical home in Pacific dates to around the mid-1980s. Houses of this vintage usually got batts or blown fiber at whatever the standard of the day was, which is well short of what is recommended now. Most are one top-up away from being right.

Downtown core has brick commercial buildings restored from the late 1800s along First and St. Louis Streets, plus 1930s-40s Route 66 motor-court era structures (Red Cedar Inn, Al-Pac Motel, Beacon Court); typical home dates to around 1991, reflecting later 20th-century suburban infill around that older core.

Meramec River flooding is documented in Pacific in 1895 and 1915, and an 1891 fire destroyed all buildings on St. Louis Street between First and Columbus; the city also straddles the Franklin/St. Louis county line.

Pacific homes in the Census numbers

The Census Bureau estimates 3,218 homes in Pacific. 170 of them (5%) went up before 1940 — 20th of 44 places on this site for pre-1940 housing. The 1970s were the busiest decade, adding 618 of today's homes (19%); 42% predate 1980 and 24% were built in 2000 or later. For Franklin County as a whole the pre-1940 share is 10%, so Pacific sits below it.

Of 3,116 occupied homes, 35% heat with utility gas and 61% with electricity; another 3% burn propane or other tank gas. Electric heat here is less common than across the county (68%), and ranks 4th of 44 on this site. Which utility program can contribute depends on the heating fuel and on who sends the bill, so that is the first thing an assessment pins down.

65% of occupied homes are owner-occupied and 66% of all homes are single-family detached houses, with 133 mobile homes in the count. With houses like these, the conversations we expect most are about an energy assessment before deciding what to fix first.

3,218 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 3,116 occupied.

Sealing comes first in Pacific

1,103 of Pacific's 3,218 homes (34%) were built in the 1980s and 1990s. The gaps in houses of that age are the parts nobody sealed: batts stuffed into the rim joist, bare spots over cathedral and tray ceilings, soffit vents buried with no baffles, can lights punched through the ceiling plane. A top-up plus a day of sealing usually covers it.

What the energy code requires in Pacific

Pacific has no residential energy code in force. Pacific deleted Chapter 11 of the IRC in its entirety and adopts no edition of the IECC, so no residential energy code is in force here. Pacific adopts the 2018 International Residential Code, in Section 500.152, by Ordinance No. 3349 of 12-20-2022, following Ord. Nos. 2249, 2542 and 3013. Section 500.153(40) then states Chapter 11, Energy Efficiency - Delete in its entirety. On the commercial side, Article II adopts the 2018 International Building Code, most recently by Ord. No. 3348 of 12-20-2022, and deletes IBC Section 101.4.6 Energy. Chapter 500 contains no adoption of any edition of the International Energy Conservation Code. The result is that Pacific has no adopted residential energy code. That does not make insulation optional — it makes the specification a conversation between you and whoever you hire, with nothing behind it but their word. It is a good reason to ask for the R-value in writing.

Do you need a permit to insulate here?

Pacific publishes no answer either way. Insulation and air sealing appear on neither the permit-required list nor the exempt list. The code's Article II notes only that exception 2 of IBC Section 105.2 was deleted; insulation is not mentioned in the readable portions of Chapter 500. We confirm it with the department before we start and pull whatever is needed. We would rather write that here than guess on your behalf.

Permits and inspections in Pacific

The published number is 636-271-0500. The department page is here.

Permitting is on us, not on you.

Rebates a Pacific homeowner can actually use

Most Pacific addresses are Ameren Missouri electric customers, and Ameren Missouri pays toward insulation through Pay As You Save: $0.20 per square foot on the attic and $0.06 per square foot on air sealing in the 2026 program year, with the rest of the cost recovered through the electric bill. The conditions: an attic going from R-20 or below to at least R-38, air sealing that cuts measured leakage by 20 percent, and twelve months in the home. CommunitySavers can include attic insulation at no charge for income-eligible households. Income-qualified households can apply to Jefferson-Franklin Community Action Corp. (JFCAC) (636-789-2686) for free weatherization instead. The full program rules are on the Franklin County page and in the rebate guide.

Nearby

Pacific borders Eureka. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in Franklin County we also cover:

How Pacific compares with its neighbors

Missouri sets none of this at state level. Across the 4 places in this table there is one adopted edition, the 2018 IRC ch. 11, and 1 of the 4 publishes a permit rule for insulation.

All 3 Franklin County jurisdictions side by side →

Common questions about insulation in Pacific

Code and permit facts checked September 10, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: ecode360.com (2, 3, 4, 5) · pacificmo.gov (2, 3) · en.wikipedia.org · censusreporter.org · city-data.com · ameren.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 636-271-0500 or your electric utility first.