How much does ductwork installation cost?

New ductwork installation costs $4,000–$10,000 for a 1,500 sq ft home and $8,000–$18,000 for a 2,500+ sq ft home. Cost per square foot of home ranges from $3–$7 for flexible duct to $6–$12 for sheet metal. Homes without existing ductwork (adding central HVAC for the first time) are at the higher end because routing through finished spaces adds significant labor.

How long does ductwork installation take?

New ductwork installation takes 2–5 days for most homes. A 1,500 sq ft home with easy access (new construction or open basement) takes 2–3 days. A 2,500 sq ft existing home with finished spaces may take 4–7 days due to routing challenges and drywall patching.

What type of ductwork is best for new installation?

Sheet metal (galvanized steel) is the best long-term choice — 30+ year lifespan, best airflow, easiest to clean. Flexible duct is more affordable and faster to install — ideal for branch runs to individual rooms. Most HVAC contractors use sheet metal for main trunk lines and flex for branches. Fiberboard is a budget option but can harbor mold in humid climates.

Do I need a permit for ductwork installation?

Yes, in most jurisdictions a mechanical permit is required for new ductwork installation. Permit costs range from $100–$400. An inspection ensures the system is properly sized and sealed. Your HVAC contractor typically pulls the permit; confirm this is included in their quote.

How many supply and return vents do I need?

A general rule: one supply vent per room (100–150 sq ft per vent), plus one large return per floor. A 1,500 sq ft two-bedroom home typically needs 8–12 supply vents and 2–3 return air grilles. Proper Manual D duct design calculates this precisely based on room load calculations.

Can ductwork be installed in a home without a basement or attic?

Yes, but it's much harder and more expensive. Options: crawlspace routing (moderate difficulty), running ducts through interior walls (high cost, requires drywall work), soffit construction to hide ducts in kitchens/hallways, or using a high-velocity mini-duct system (SpacePak, Unico) that fits through 2-inch holes in walls. Many slab-on-grade homes choose mini-splits instead of traditional ductwork.

Home / Home Maintenance / Ductwork Installation Cost Calculator

🔧 Ductwork Installation Cost Calculator

Estimate the cost to install brand-new ductwork in a home that never had central heating or cooling — material, labor, and total cost by home size

Who Should Use This

Homeowners adding central HVAC to a home that currently uses window units, radiant heat, or mini-splits — and anyone planning a new construction project.

Purpose

Calculate new ductwork installation cost by home size, number of floors, duct material, and access difficulty — plus estimated number of vents and cost per square foot.

Example

Installing new sheet metal ductwork in a 1,800 sq ft two-story existing home with moderate access typically costs $8,000–$14,000. New construction with open access runs $4,000–$8,000 for the same size.

Installation Details

Home Size (sq ft)

Number of Stories

Duct Material

Installation Type / Access

Add-Ons

Mastic Sealing on All Joints

Professional application for airtight system (+$400–$900)

Duct Insulation (R-8) in Unconditioned Spaces

Required by code in most states for attic/crawlspace runs (+$600–$1,500)

Zoning Dampers (2-zone system)

Independent temperature control per zone (+$800–$2,000)

Permit & Inspection

Required in most jurisdictions (+$100–$400)

💡 Pro Tip: New ductwork in an existing finished home is one of the most labor-intensive HVAC projects. If your home has no ducts, get quotes for both traditional ductwork AND a multi-zone mini-split system — mini-splits are often 30–50% less expensive in finished homes without attic/basement access.

Installation Cost Estimate

Total Installed Cost

$— – $—

Including all selected options

Cost Per Sq Ft of Home

$— – $—

Estimated linear footage

Cost Breakdown

Trunk Duct Materials$—

Branch / Flex Duct Materials$—

Labor (Fabrication + Install)$—

Supply & Return Registers$—

Mastic Sealing$—

Duct Insulation$—

Zoning Dampers$—

Permit & Inspection$—

System Summary

Est. Supply Vents—

Est. Return Air Grilles—

Est. Total Linear Footage—

How It Works

4 Steps to Your Ductwork Estimate

Enter Home Size

Select square footage and number of stories to estimate total linear footage of ductwork needed.

Choose Material

Sheet metal + flex is the standard; all sheet metal is premium; all flex is the budget option.

Set Access Type

New construction vs. existing home is the biggest cost variable — open framing vs. finished walls.

Add Options

Include mastic sealing, insulation, and zoning for a complete, code-compliant system estimate.

New Ductwork Installation Cost Factors

Access is the dominant cost driver. New construction with open framing allows contractors to route ducts efficiently through floor joists and wall cavities before drywall goes up. In an existing finished home, every run requires creative routing, cutting through finished materials, and patching — often doubling labor costs.

Home size and number of floors determine material quantity. A single-story home is easier than a two-story because a single trunk line serves all rooms. Two-story homes need separate trunks per floor and a larger return system.

Material choice affects both cost and long-term performance. The industry standard is sheet metal trunk lines (better airflow and longevity) with flexible duct branches (faster installation). All sheet metal adds 20–40% to material cost but provides superior airflow and lasts 30+ years.

Ductwork vs. Mini-Split: Which Is Right?

For existing homes without ducts, compare both options carefully before committing:

Choose ductwork when: You want whole-home central AC with one thermostat, you have accessible attic/basement, or you're doing a major renovation with walls open
Choose mini-splits when: Home is finished with no attic/basement access, you want zone control, you're cooling 3 or fewer areas, or budget is tight
Ductwork advantage: Uniform heating/cooling, familiar controls, better for large homes (4+ bedrooms)
Mini-split advantage: No ductwork needed, more efficient (no duct losses), faster installation, lower cost in finished homes
Rule of thumb: If ductwork requires opening finished walls in more than 3 rooms, mini-splits are usually cheaper and less disruptive

Buyer's Guide

Ductwork Installation — What to Know

Materials, access, sizing, and installation tips

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New Construction Advantage

Installing ductwork in new construction before drywall is 40–60% less expensive than retrofitting. If you're planning an addition or major renovation, schedule HVAC rough-in while walls are open. Coordinate with your HVAC contractor early — duct routing affects wall framing plans.

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Sheet Metal Trunks + Flex Branches

The industry standard hybrid approach: rectangular or round sheet metal for main trunk lines (best airflow efficiency), flexible duct for 6–8 ft branches to individual vents. Flex duct must be kept short and straight — long, kinked flex runs waste 15–25% of airflow.

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Manual D Duct Sizing

Properly sized ductwork requires a Manual D calculation — matching duct diameter to room airflow requirements. Undersized ducts cause whistling, pressure imbalances, and poor comfort. Ask your contractor to provide Manual D documentation; any reputable contractor will do this as standard practice.

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Mastic Sealing — Always

Mastic (elastomeric paste) applied to all duct joints prevents air leakage. Standard "silver" duct tape fails within 2–5 years. ENERGY STAR homes require less than 4% duct leakage to conditioned space. Mastic sealing at installation adds $400–$900 but is the single best investment in system efficiency.

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Insulate Ducts in Unconditioned Spaces

Any duct run through an attic, crawlspace, or garage must be insulated to at least R-6 (R-8 recommended, required by code in many states). Uninsulated ducts in attics can lose 20–30% of heating/cooling energy to the unconditioned space. Factor this into your budget from day one.

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Return Air System

A properly sized return air system is as important as supply. Undersized returns cause pressure imbalances, drafty rooms, and efficiency loss. Minimum: one return per floor. Ideal: one return per bedroom (central-return systems are a common budget shortcut that causes long-term comfort issues).

Common Questions

Ductwork Installation FAQ

Cost by home size (new installation, existing home with moderate access):

Under 1,000 sq ft: $4,000–$8,000
1,000–1,500 sq ft: $5,500–$10,000
1,500–2,000 sq ft: $7,000–$13,000
2,000–2,500 sq ft: $8,500–$15,000
2,500–3,500 sq ft: $11,000–$20,000

New construction discount: Subtract 35–45% for open-framing new construction access.

Difficult access premium: Add 40–70% for finished homes requiring wall penetrations and drywall repair.

Recommended: Sheet metal trunks + flexible duct branches

Sheet metal trunk lines: Best airflow, 30+ year lifespan, easier to clean, pest-resistant. Use for all main supply and return trunk runs.
Flex duct branches: Faster to install, lower cost, good for short (under 8 ft) straight runs to each room. Keep bends gradual — tight bends reduce airflow significantly.

All sheet metal: Premium choice — 20–40% more expensive but maximizes system efficiency. Often specified in high-performance homes.

All flexible duct: Budget option — lower cost but more prone to long-term airflow problems if not properly supported and kept straight.

Avoid fiberboard in humid climates — absorbs moisture and can harbor mold.

Supply vents: Roughly one per 100–150 sq ft, or one per room for rooms under 200 sq ft. Add extra vents for large open spaces.

Return air grilles: Minimum one per floor; ideal is one per bedroom plus one in the main living area. Undersized returns are the most common ductwork mistake.

Example for 2,000 sq ft two-story home:

First floor (1,000 sq ft): 7–9 supply vents, 2 return grilles
Second floor (1,000 sq ft): 6–8 supply vents, 2–3 return grilles
Total: 13–17 supply, 4–5 return

Manual D calculation from your HVAC contractor gives precise vent sizing and quantity based on room-by-room load calculations.

Yes, but it's challenging and expensive. Options:

Attic distribution: Run main trunk in attic, drop branches through interior walls. Works well for single-story slab homes with accessible attic. Cost: similar to standard installation.
Soffit construction: Build a dropped soffit in hallways and kitchens to hide horizontal duct runs. Requires drywall work but avoids opening walls. Cost: add $1,500–$4,000 for soffits.
High-velocity mini-duct: Systems like SpacePak or Unico use 2-inch diameter flexible tubing that snakes through 2-inch holes in walls without major renovation. Cost: $8,000–$15,000 — higher than traditional duct but much less invasive.
Mini-split alternative: Often the most practical and cost-effective choice for slab homes without attic access.

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