New Furnace and Ductwork Cost Guide: What to Expect

Replacing a heating system involves more than picking a furnace; homeowners must budget for both the new furnace and ductwork cost to ensure efficient, reliable heating and indoor air quality.

Item	Typical Cost Range (USD)
Furnace Unit (Gas, Mid-Efficiency)	$1,200 – $2,500
High-Efficiency Furnace (AFUE 90%+)	$2,500 – $6,000
Duct Repair / Minor Sealing	$300 – $1,200
Duct Replacement (Partial)	$1,000 – $3,500
Full Duct Replacement	$3,000 – $10,000+
Installation Labor	$800 – $3,000+
Total Typical Project Cost	$3,000 – $12,000+

How Furnace And Ductwork Costs Are Calculated

Costs break down into equipment, labor, materials, and project complexity. The furnace model and efficiency class determine the unit price, while ductwork costs depend on material, layout, and whether existing ducts are reusable.

Local labor rates, permitting, and disposal fees also influence the final invoice. Regional variations can change costs by 10–40% across the United States.

Typical Furnace Types And Their Price Points

Gas Furnaces

Gas furnaces are common in many U.S. homes. Mid-efficiency units (80–85% AFUE) are least expensive upfront, while high-efficiency models (90–98% AFUE) cost more but save on fuel bills.

Average unit costs: $1,200–$6,000 depending on efficiency and brand. Expect higher prices for two-stage or modulating burners.

Electric Furnaces

Electric furnaces have lower equipment costs and simpler installation but higher operating costs in most areas with moderate electricity prices. Units commonly range $700–$3,000.

Heat Pumps

Heat pumps provide both heating and cooling and can replace furnaces in many climates. Prices typically run from $3,000 to $8,000 installed, with higher-end ducted mini-split or multi-zone systems costing more.

What Drives Ductwork Costs

Ductwork costs depend on whether ducts are accessible, damaged, well-sized, and properly sealed. Key cost drivers include:

• Accessibility: Attic and crawlspace access increases labor hours.
• Material: Flexible duct vs. metal spiral duct vs. fiberglass-lined: metal is more durable and more expensive.
• Length and Complexity: Multi-story homes and long runs increase material and labor.
• Insulation and Sealing: Proper insulation and sealing add to costs but reduce energy loss.

Signs We Need New Ductwork When Replacing A Furnace

Not all furnace replacements require new ducts, but these signs suggest replacement or major repair is advisable:

• Pervasive uneven heating across rooms.
• Visible duct corrosion, disconnected sections, or large tears.
• Consistently high energy bills after recent tune-ups.
• Poor indoor air quality with dust buildup despite filtration.
• Ducts undersized for a new, higher-capacity furnace leading to noise or performance issues.

Estimating The Total Cost To Replace Furnace And Ducts

Estimate the project cost by adding furnace, ductwork, labor, and extras. Example scenarios:

• Basic Swap (Furnace Only): Mid-efficiency furnace + standard install = $2,000–$4,500.
• Furnace + Minor Duct Repair/Sealing: Add $300–$1,200, total $2,500–$6,000.
• Furnace + Partial Duct Replacement: Replace main trunk or some runs: add $1,000–$3,500, total $4,000–$9,000.
• Furnace + Full Duct Replacement: New duct system in a large home: total often $7,000–$15,000 depending on materials and complexity.

Labor And Installation Considerations

Professional installation is critical for safety and warranty compliance. Labor often represents 25–50% of the total cost depending on project complexity.

Qualified HVAC contractors perform load calculations (Manual J), duct design (Manual D), and ensure correct furnace sizing. Incorrect sizing leads to comfort issues and shorter equipment life.

Energy Efficiency, Rebates, And Long-Term Savings

Choosing a high-efficiency furnace and properly sealed, insulated ducts reduces fuel use and operating costs. Payback depends on fuel prices, climate, and usage patterns.

Federal, state, and utility rebates may offset initial costs. Many utilities offer incentives for high-efficiency furnaces, heat pumps, and duct sealing—research local programs for potential savings.

Financing And Budgeting Tips

Many homeowners finance HVAC projects via contractor financing, home equity lines, or energy-efficiency loans. Typical financing options include 0% introductory APR offers, fixed-term loans, and municipal programs.

Obtain multiple quotes and compare included warranties, labor guarantees, and scope of work to avoid surprises. Ask for itemized bids to see equipment, materials, and labor separated.

How To Get Accurate Quotes

To receive precise estimates, homeowners should ask contractors to:

• Perform a Manual J load calculation to size the furnace properly.
• Inspect and document duct condition with photos.
• Provide an itemized written estimate including permits and disposal.
• Explain warranty coverage for both equipment and labor.

Common Upgrades And Their Costs

Upgrade	Estimated Cost
Smart Thermostat	$150 – $350 Installed
Air Cleaner / Whole-House Filtration	$400 – $2,500
UV Germicidal Light	$300 – $800
Zone Control Dampers	$1,000 – $3,000+
Insulated Ducting (R-6 or Higher)	$1 – $3 per linear foot additional

DIY Vs. Professional Work: Risks And Benefits

DIY projects can save money on simple tasks like filter changes or minor sealing, but furnace replacement and duct redesign require licensed professionals.

Risks of DIY include improper combustion venting, gas leaks, electrical hazards, voided warranties, and code violations. For safety and performance, hire licensed HVAC technicians for major work.

What To Ask Contractors During Bids

Essential questions include:

• Are you licensed, bonded, and insured in this state?
• Will you perform Manual J and D calculations?
• What brand and model do you recommend and why?
• What is the total project timeline and start date?
• What warranties cover parts and labor, and is there a performance guarantee?

Regional Cost Variations In The United States

Northern climates often see higher demand for efficient furnaces and may face higher labor costs during peak seasons. Southern states may prioritize heat pumps and AC integration.

Urban areas typically have higher labor rates than rural regions. Always request local references and verify contractor reputation through review sites and licensing boards.

Case Studies: Typical Projects And Outcomes

Small Single-Story Home With Old Furnace

Scenario: 1,200 sq ft home with 15-year-old furnace and leaky flex ducts. Solution: Replace with high-efficiency gas furnace, seal ducts, replace 2 runs. Cost: $4,500. Result: 15–25% heating energy savings and improved comfort.

Large Two-Story Home Needing Full Duct Replacement

Scenario: 3,200 sq ft home with undersized and damaged ducts. Solution: Full metal duct redesign, high-efficiency furnace, zoning. Cost: $12,500. Result: Balanced rooms, lower noise, better air quality, potential energy savings over time.

Maintenance To Extend Furnace And Duct Lifespan

Regular maintenance prevents premature failure. Annual tune-ups, filter changes every 1–3 months, and periodic duct inspections help maintain efficiency.

Seal duct joints with mastic or UL-181 tape and maintain proper insulation in unconditioned spaces to reduce heat loss and condensation risk.

Resources For Further Research

Homeowners can consult the Department of Energy for efficiency guidance, ENERGY STAR for high-efficiency equipment, and local utility websites for rebates and incentives.

Professional organizations like ACCA (Air Conditioning Contractors of America) provide standards for load calculations and duct design that reputable contractors follow.

For a reliable project estimate, gather three written bids, confirm licensing, and compare equipment efficiency, installation quality, warranties, and financing options to determine the best value.