Thermally Modified Wood Siding Price in 2026: What You’ll Pay and Why It Varies

Thermally modified wood siding is one of those materials people fall for fast. It looks like real timber because it is real timber. It also feels “architectural,” which is why it shows up on modern homes, boutique cafés, and high-end renovations.

Then you start pricing it.       

One supplier quotes by linear foot. Another talks in square feet. Someone else sells bundles. Your contractor mentions rainscreens, flashings, trim packages, and suddenly, you are not pricing siding anymore. You are pricing a full exterior system.

This guide breaks down the real numbers you’re likely to see, what actually drives the cost, and how to estimate your total without guessing.

Thermally modified wood siding price range

Typical material-only range (boards only)
Many homeowners commonly see about $5 to $16 per square foot, depending on the wood species, grade, profile, and finish.

Typical installed range

Installed pricing often lands around $12 to $30+ per square foot, with premium hardwoodcladding, complex elevations, and high-detail installs pushing beyond that.

A practical way to think about it

If your design is simple and you choose a pine-based Thermowood profile, you can stay near the lower bands. If you want premium hardwood, flawless aesthetics, and tight modern detailing, expect the upper bands.

What thermally modified wood actually is

Thermally modified wood is lumber that’s heat-treated in a controlled environment. The process changes the wood’s structure so it takes on less moisture, moves less with seasons, and becomes more resistant to decay.

That stability is why it’s popular for clean exterior lines. You are paying for a wood façade that behaves more predictably than many conventional boards.

Why does the price feel confusing

Thermo siding is frequently sold in ways that make comparison hard.

1. Linear foot pricing

Common with tongue-and-groove, shiplap, and rainscreen profiles.

2. Square foot pricing

More straightforward, but not always used.

3. Net coverage vs nominal size

This is where budgets get wrecked. A “1×6” board does not always cover 6 inches once you account for overlap or the tongue.

If you compare products, always convert everything into “net installed coverage” and then into a square-foot price.

How to convert linear feet to square feet

Use this clean conversion.

1. Find the board’s net coverage width (in inches).
2. Convert inches to feet by dividing by 12.
3. Multiply by 1 foot length to get square feet covered per linear foot.
4. Divide the price per linear foot by the square feet covered.

Example (simple illustration)

• If net coverage is 5 inches, that is 5 ÷ 12 = 0.4167 sq ft per linear foot.
• If a board costs $2.50 per linear foot, then $2.50 ÷ 0.4167 = $6.00 per sq ft.

This is the fastest way to compare suppliers without getting misled.

What drives thermally modified wood siding cost

Think of pricing like a stack of dials. Each dial you turn nudges the total.

1. Species choice

Softwoods (often lower cost)

Thermally modified pine and similar options usually start more accessibly.

Hardwoods (often higher cost)

Thermally modified ash, oak, and other hardwood claddings are commonly priced as premium façade materials.

2. Grade and visual consistency

1. Clear grades cost more
   Fewer knots, calmer grain, more uniform walls.
2. Knotty grades cost less
   More character, more variation, often better value if your design welcomes texture.

3. Profile and milling

Simple profiles are cheaper to produce and faster to install.
Complex shapes, end-matched systems, and hidden-fastener profiles usually cost more.

4. Thickness and width

More material equals higher cost.
Wider boards also raise waste and require more careful installation to keep lines clean.

5. Finish choice

1. Unfinished boards

Lower upfront cost, but you decide the finish strategy later.

2. Factory-finished or pre-oiled

Higher purchase price, but less work on-site and more consistent appearance.

3. Charred or brushed surfaces

Usually premium because it adds processing, labor, and visual positioning.

6. Fasteners and corrosion resistance

Exterior wood cladding often performs best with quality fasteners. In humid zones or coastal air, corrosion-resistant choices can add cost but reduce headaches later.

7. Shipping, lead times, and long lengths

Long boards are expensive to transport and easy to damage in transit. If you want extra-long runs for a seamless look, shipping can become a real line item.

Installed cost breakdown: what you’re actually paying for

Material is only part of the invoice. Installation includes system details that protect the wood and the wall behind it.

1. Labor and wall complexity

Cost rises when your home has:

1. Many windows and doors
2. Multiple corners and bump-outs
3. Tall elevations requiring staging
4. Tight reveals details and modern trimless looks
5. Curves, dormers, or uneven substrates

2. Rainscreen and moisture control

A proper wood siding build often includes:

1. Weather-resistive barrier
2. Flashings around openings
3. Furring strips or battens for ventilation
4. Bug screens or vent strips
5. Corner details and trims

This isn’t a fancy upgrade. It’s part of what keeps the assembly dry, stable, and durable.

3. Removal and prep

If you are replacing old siding, the quote may include:

1. Tear-off and disposal
2. Sheathing repair
3. Mold or rot remediation
4. Wall straightening to keep reveals crisp

Those items can dramatically change total cost, even if your board price stays the same.

Budget bands you can use for planning

Here’s a helpful way to frame it while you shop.

1. Value-focused thermo cladding

Often suits simpler elevations, softwood options, and straightforward trims.

2. Mid-range modern façade

Common for balanced projects where you want clean lines, a rainscreen detail, and a consistent finish strategy.

3. Architectural premium

Typical for hardwood thermo cladding, custom detailing, long board lengths, and highly visible front elevations where perfection matters.

If a quote comes in way above your expectations, it is usually because the installer is pricing the full assembly correctly, not because the contractor is “overcharging.”

Simple estimator: get your rough total in 3 minutes

Use this approach to budget before you ever request quotes.

Step 1: estimate exterior wall area

This is not your floor area. It’s the total square footage of all exterior walls, minus major openings if you want a tighter estimate.

Step 2: Pick a planning range

1. Material-only planning: $5–$16 per sq ft
2. Installed planning: $12–$30+ per sq ft

Step 3: Add a waste buffer       

A common planning buffer is 10% to cover offcuts, mistakes, and matching.

Example

If your exterior wall area is 2,000 sq ft:

1. Material-only rough range
2. 2,000 × $5 to $16 = $10,000 to $32,000
3. Add 10% buffer: $11,000 to $35,200
4. Installed rough range
5. 2,000 × $12 to $30 = $24,000 to $60,000
6. Add 10% buffer: $26,400 to $66,000

This range is wide on purpose. Thermo cladding varies a lot, and installations vary even more.

Thermally modified wood vs other siding options

Most people consider thermo wood because they want the warmth of real wood without the stress of constant movement and distortion.

Here’s the honest comparison.                             

1. Standard wood siding

Usually cheaper upfront, but more prone to seasonal movement depending on species and treatment.

2. Fiber cement

Often competitive in installed price for many homes, with different trade-offs in texture and detailing.

3. Engineered wood siding

Can be cost-effective, with consistent finishes, though it does not deliver the same “real wood” depth up close.

4. Metal cladding

Strong and modern, often higher in material cost, and it changes the visual vibe completely.

Thermo wood typically wins on “real wood feel” with a more stable behavior than many conventional boards.

Maintenance: what homeowners should actually expect

A lot of disappointment happens because people confuse two different goals.

Goal 1: keep the original color

If you want that rich brown tone to stay, you will likely need a UV-protective finish and periodic refreshes.

Goal 2: accept natural weathering

If you are happy with a silver-grey patina, maintenance can be simpler, though good water management still matters.

Thermally modified wood is more stable than many untreated options, but every exterior surface still lives outdoors. Sun and water are always at work.

What to ask before you sign a quote

If you want clean comparisons, ask these questions and make each bidder answer the same way.

1. Are you pricing by linear foot or square foot?
2. What net coverage width are you using for conversion?
3. What exact species and grade is included?
4. What profile and thickness are included?
5. Is the product unfinished, pre-oiled, or factory-finished?
6. Are battens, WRB, flashings, and vents included?
7. What waste percentage is included in your material takeoff?
8. What fasteners will you use and why?
9. How are corners, window trims, and terminations detailed?
10. What is the expected finish maintenance schedule for the look I want?

If a contractor cannot explain these clearly, that’s a risk signal.

Common mistakes that inflate costs

1. Comparing linear-foot prices without converting to net square-foot coverage
2. Ignoring trim and corner packages
3. Skipping rainscreen details in early budgeting
4. Underestimating waste on modern layouts with many openings
5. Choosing a finish goal after installation planning is done
6. Picking a premium board length standard without checking the shipping cost

FAQs

Is thermally modified wood siding worth the price?

It can be worth it if you care about real wood aesthetics, improved stability, and an architectural look that holds its lines over time. It’s less compelling if your priority is the lowest upfront cost.

What is a realistic installed cost per square foot?

Many projects land in the teens to upper twenties per square foot installed, with premium hardwood cladding and complex builds going higher.

Does thermo wood siding need sealing?

It depends on your appearance goal. You may finish it to retain color, or let it weather naturally. Either way, moisture management behind the siding remains important.

Why are two quotes so different for the same house?

Most of the time, the scope is not identical. One quote may include full rainscreen detailing, flashings, trims, staging, tear-off, and wall repairs. Another may be pricing a thinner scope and leaving the rest for change orders later.

Final takeaway

Thermally modified wood siding is not “just boards.” It is a premium exterior system where species, profile, finish, and installation detailing decide the final number.

If you convert every product to net square-foot coverage and force every contractor to quote the same scope, you’ll get clean, comparable pricing. That is how you avoid confusion and choose based on value, not noise.

Related Resources:

• https://toolsframe.com/upcycling-wood/
• https://toolsframe.com/how-to-remove-nails-from-wood/
• https://toolsframe.com/best-combination-square-for-woodworking/