HVAC replacement cost in St. Louis, MO

Average $7,500; common $5,000 to $12,500; up to $22,000 with new ductwork.

A typical HVAC replacement in St. Louis, MO is about $7,850, including a permit fee of $65.

What we assumed

For the permit line we assumed a Residential Use Group R-3 like-for-like 3-ton (36,000 BTU) furnace plus condensing unit under City of St. Louis mechanical permit fees (Ordinance 70800), so the typical fee is $65 ($25 application + $40 combination). Low $65 uses the same combination path. High $105 bills furnace and condensing separately ($25 + $40 + $40). These totals are for the City of St. Louis, not St. Louis County. Full arithmetic is in the calculation note on this page.

Questions about this estimate

How much does HVAC replacement cost in St. Louis, MO?

Typical all-in is about $7,850. The official local permit fee of $65 ($25 application + $40 combination) is included in the all-in.

Is a permit required for HVAC replacement in St. Louis, MO?

Yes. City of St. Louis Building Division requires a permit for a typical HVAC replacement in St. Louis, MO. The typical listed fee is $65. The official path is Ordinance 70800 Residential Use Group R-3: a $25 application fee plus $40 for a combination furnace/condensing unit on the typical and low bands. The documented 3-ton like-for-like split uses that combination line. High bills furnace and condensing separately.

What is included in this HVAC replacement estimate for St. Louis, MO?

The estimate is labor adjusted for local wages in St. Louis, MO, plus materials at the national figure, at the typical size in the table above. The official typical permit fee of $65 is included in the all-in typical. That $65 is Application fee $25 plus Combination furnace/condensing unit $40. The high separate-billing path is not included in the typical. Electrical is not dollarized on this row.

Why might the St. Louis permit fee differ from this typical figure?

The official St. Louis, MO fee comes from City of St. Louis mechanical permit fees (Ordinance 70800) (flat). The typical path is $65 for a Residential Use Group R-3 like-for-like 3-ton (36,000 BTU) combination furnace/condensing unit under Ordinance 70800 ($25 + $40). Low $65, typical $65, and high $105 are in the calculation note on this page. The high path bills furnace and condensing separately at $25 + $40 + $40 = $105 and is not added on top of the typical $65 combination total. This row does not invent an electrical permit dollar or a St. Louis County mechanical fee. Verify with City of St. Louis Building Division.

How is the typical permit fee calculated for HVAC replacement in St. Louis, MO?

Listed Ordinance 70800 bands are low $65 and typical $65 on the combination path ($25 + $40), and high $105 when furnace and condensing are billed separately ($25 + $40 + $40). Full arithmetic is in the calculation note on this page.

What project value is this HVAC replacement permit fee based on in St. Louis, MO?

The official typical project value is $7,500. This permit fee is the Ordinance 70800 flat mechanical path, not a valuation total. Low, typical, and high totals are in the calculation note on this page.

How much does HVAC replacement cost for 1 or 2 systems in St. Louis?

The documented typical job is a 3-ton (36,000 BTU) like-for-like split system. This cost model prices that job as one system. The cost-by-size rows include 1 system and 2 systems. At 1 system in St. Louis, MO the all-in is $5,255 low, $7,850 typical, and $22,941 high. Those all-in figures add the model's rounded permit for the official Ordinance 70800 bands. The official fees are $65, $65, and $105. The model rounds each to the nearest dollar before adding it, so the all-in uses $65 on the low, $65 on the typical, and $105 on the high. The permit is a flat mechanical fee, so it is not rescaled when the system count changes. At 2 systems the all-in typical is $15,635.

What does the typical $65 HVAC permit fee include in St. Louis?

The official typical HVAC permit in St. Louis, MO is $65. That total is Application fee $25 plus Combination furnace/condensing unit $40. Both of those extras are included. The high separate-billing path ($25 + $40 + $40 = $105) is not part of that typical. Electrical is not dollarized on this row.

Why are the low, typical, and high HVAC permit fees $65, $65, and $105 in St. Louis?

The low, typical, and high fees are three applications of the same City of St. Louis Ordinance 70800 Residential Use Group R-3 schedule, not three different schedules. Typical/low = $25 + $40 combination = $65.00. High = $25 + $40 furnace + $40 condensing = $105.00. The $80 separate-billing extra is high path only and is not added on top of the typical $65.

Is electrical included in the St. Louis HVAC permit fee?

Electrical is not dollarized on this listed row. The typical $65 is the Ordinance 70800 combination path only ($25 application + $40 combination). This row does not invent an electrical permit dollar.

Is the St. Louis HVAC permit the same as St. Louis County?

These totals are for the City of St. Louis Building Division. St. Louis is an independent city, not St. Louis County, and this row does not use a St. Louis County mechanical fee. Confirm the Residential Use Group R-3 combination line with the City of St. Louis Building Division before you apply.