Fiber Cement Siding Cost in 2026: Price per Square, Hardie and Allura Warranty Terms

Start with the unit: wall square, not house size

Homewyse's September 2026 model puts basic installed fiber cement siding at $9.32–$15.28 per square foot. The publisher describes a common horizontal lap material and favorable working conditions. It is an illustrative unit-cost model, not a price quote for James Hardie, Allura, or any named finish. Its input is finished wall area including openings. It includes a basic installation labor description and job supplies, while permit fees, sales tax, repairs to existing framing and general contractor supervision sit outside the example estimate. Homewyse lists old-siding removal as an option, so ask whether it is active in any calculation you use.

A Portland, Oregon, James Hardie installer, Cornerstone Renovations, publishes $15–$25 per square foot of wall area for its full installation scope. Its description includes old-siding tear-off and disposal, inspection and repair of sheathing where needed, a weather-resistive barrier and flashing, Hardie siding, trim, corners and cleanup. That scope is broader than a basic line in a national unit model and the range is for a named local market. The two ranges overlap at their boundary, but they are not competing prices for an identical job.

A siding square means 100 square feet of wall, as the Portland installer explains. The amounts below are straightforward conversions of the linked per-foot figures. They are useful for reading a contractor's quantity sheet, not substitute bids.

The contractor's wall area can be very different from the square footage in a real-estate listing. Living area measures floors; siding area measures exterior wall faces and gables. Openings may be deducted for panel takeoff yet add labor back through casing and flashing. Thus the question for a proposal is wall area, not floor area: ask for the measured gross wall area, the deducted openings, the net panel quantity and the allowance for waste. Cornerstone says it measures each wall rather than multiplying floor area by a rule of thumb. Homewyse's input convention counts openings, which makes its cost per foot especially easy to misapply to an installer takeoff that deducts them. An estimate can be internally consistent under either convention; the unit and inclusions must be explicit.

Hardie and Allura are product families, not one board

The general siding replacement guide compares several materials. Here the useful comparison is within fiber cement: horizontal lap, large panels, shake-like profiles, primed boards and factory-finished boards entail different work. A line item reading only “fiber cement” cannot tell you which finish labor is included or which warranty you will receive.

The Portland contractor reports that its projects may put HardiePlank on main walls, HardieShingle in gables, and HardiePanel with battens on an accent wall. That is a description of its own practice, not a brand price list. A panel face may cover wall quickly, while battens and trim increase detail labor; shakes change the number of courses and cuts. Without public, same-market prices for those exact assemblies, no honest table can assign each named line a precise installed premium. Instead, compare the products and documents that an actual bid can identify.

For Allura Lap, the manufacturer's June 2026 submittal sheet lists 12-foot lengths and 5/16-inch thickness. Those measurements help identify the product, but they are not a universal cost formula. Allura says its lap siding may come primed for field finishing or factory-finished with Spectrum. The factory finish versus field paint choice changes who performs finishing and when: a quote for primed boards needs a painting scope, while a factory-finished quote still needs a clear plan for exposed cuts and touch-ups. The submittal sheet does not publish prices for either option, so I have not assigned one a numeric premium.

The Hardie warranty PDF is a manufacturer-authored document hosted on a distributor site. It identifies HZ5 versions of HardiePlank, HardiePanel, HardieShingle, HardieTrim and other products. The file name says HZ10, while the visible first page names HZ5; I used the content on the page, not the file name, to describe its coverage. That mismatch is a practical reason to obtain the exact warranty supplied with your chosen product and market. Allura's warranty is hosted on Allura's own site and names Lap, Panel, Shake and Soffit.

One Portland price, several possible product mixes

Cornerstone's Portland range is a useful regional counterpoint to the national model because the installer describes what goes into its price. It is not evidence that every Portland contractor charges the same, or that a Hardie product has a nationally fixed premium over Allura. The local source says it commonly mixes Hardie profiles on one house. A $/square answer from that company therefore reflects the mix, existing wall condition and trim package, not a single box of HardiePlank. For a Portland homeowner, request a takeoff that separates main-wall lap, gable accent material, panels and battens. For a homeowner elsewhere, use the description as a scope checklist and seek local bids.

What the warranty documents make you pay for

The two product PDFs promise a term of 30 years, but that number does not mean a full future re-side is paid for. The decisive clause in both is the labor exclusion. Allura's product PDF and the Hardie HZ5 PDF both say the manufacturer will not refund or pay labor or accessory material costs connected with a covered product defect. A replacement board can be furnished while the owner still pays to reach, remove and reinstall it and to restore adjoining materials. Ask the installation company whether its workmanship promise covers replacement labor for a manufacturer-approved product claim, and for how long. Get that answer in the contract, because it is separate from the substrate PDF.

There is a real difference in the notice window. The Allura PDF requires written notice within 30 days after discovering a claimed defect and before permanent repair. The Hardie HZ5 PDF requires written notice within 90 days and also says to notify before permanent repair. This is not a prediction of which company is more likely to approve a claim. It is an operational difference that matters if a board fails: photograph the issue, preserve purchase and product records, notify the manufacturer under the document attached to your purchase, and avoid changing the evidence before it can inspect.

Both PDFs limit the remedy to the defective portion of the product, with a manufacturer option to refund or replace, or pay up to twice the original retail cost of that portion. “Twice” is a ceiling on one remedy in a specific claim, not a measure of the total cost to fix a wall. The documents also restrict who is a covered person: the first retail buyer, the first building owner and the first transferee are named. A seller calling the warranty “transferable” should point to that coverage definition, not merely to the word in marketing copy.

Allura's PDF provides another cost-relevant extraction: it conditions coverage on storage and installation according to its instructions, and warns that installing wet product may cause staining, shrinkage or efflorescence outside coverage. An installer should document delivery, storage and wall preparation instead of assuming a product warranty will resolve any later cosmetic issue. The Hardie document similarly ties coverage to its named product and the written claim process. In both cases, the product warranty is a limited remedy for a covered product issue; it is not a substitute for a complete work scope.

The assembly behind the $/square figure

Fiber cement's board price is only part of an exterior wall job. The full wall assembly in the Portland contractor's description includes tear-off, inspection, weather barrier, flashing, trim and cleanup. The basic Homewyse model lists a barrier and supplies but does not give a bid-specific allowance for discovering damaged framing. That difference should be visible on a proposal rather than buried in “labor and materials.”

Ask for a simple map of what is being removed. Existing siding may conceal sheathing or flashing that cannot be examined before demolition. A contract can state a per-sheet sheathing replacement price and an approval process without inventing a total for damage nobody has seen. Write down which openings will receive new flashing, how the weather-resistive barrier is integrated at those openings, and whether the quote includes fascia, soffit, corner boards and window trim. A contractor's base lap-siding number may be perfectly honest while those items are separate. Two totals cannot be compared until they cover the same work.

The finish deserves its own line. Allura's current submittal document explicitly offers primed and Spectrum factory-finished lap boards. A primed quote should identify field painting, color and who returns for touch-ups. A finished quote should identify the finish warranty document, because the product warranty extracted above governs the fiber-cement substrate; it does not itself establish the coating's separate terms. The same distinction matters for a Hardie bid offered with a factory finish. A substrate term and a finish term are not one promise, and neither should be substituted for the installer's workmanship terms.

Homewyse's model also excludes permits and sales tax, while its materials example assumes available stock. A proposed product may have a different supply route, color availability and delivery cost in your market. Request an explicit statement on permits and inspections, and whether the quoted line can be obtained in the promised color and profile. That is more useful than guessing a national premium from a brand name.

What a low allowance leaves undecided

A price per siding square can describe panel installation while leaving the hard parts of the wall at a different unit. Trim may be priced by linear foot, a sheathing repair by sheet, painting as a separate trade, and disposal as a single project charge. When that happens, multiplying the siding squares by the advertised unit price produces only one part of the job. The Homewyse and Portland sources illustrate this in their different scopes: one is an educational unit model, and the other is a local installer describing a complete re-side. Neither can tell you which add-ons your own house needs until the walls are measured and opened.

Ask for allowances only where the quantity is genuinely unknown. A bidder can measure the planned trim and known wall area in advance. Sheathing damage behind old cladding is uncertain, so a unit price and approval process are more honest than an unsupported flat amount. The same approach applies to damaged framing or an unexpected second layer of siding. The contract should identify what evidence triggers extra work and who may approve it. If a contractor offers a higher total with tear-off and flashing fully specified, that total may be more useful for budgeting than a lower headline $/square with the wall assembly undefined.

The product schedule should also specify where each profile goes. A main-wall lap panel, an accent panel and a shake-look gable are distinct quantities. A single blended unit price can be reasonable after those areas are measured, but you should still be able to see the product mix behind it. This matters if a substitution is proposed after the contract is signed: a different profile or finish can change labor and the applicable manufacturer document even if the material category remains fiber cement. Attach a material schedule and ask for a written change if a named product becomes unavailable.

That schedule is also a useful way to compare apparent savings. If one proposal specifies factory-finished lap siding everywhere and another specifies primed boards with painting priced later, the two headline siding totals are measuring different purchases. Ask each bidder to show the final finish as delivered, and to identify who repairs handling marks or exposed cuts. A written finish scope keeps the price comparison tied to the appearance and maintenance obligation you will actually inherit. If the installer proposes an alternative line after ordering, compare its product warranty and finish document again. Matching the word “fiber cement” on both invoices does not establish that the warranty, finish, profile or installation instructions are the same.

The warranty PDFs make the paper trail part of that schedule. They define claims around a covered product, purchase and installation, not around a vague phrase like “Hardie house” or “Allura siding.” Preserve the invoice, product labels or delivery paperwork, the selected finish, and the installer's written scope. Those records make it possible to identify which board and warranty a later claim concerns. They also help separate a product defect from a problem with flashing, paint or installation, which the product warranty alone may not resolve.

How I would read two fiber cement bids

Put the bids side by side with the same measurement convention: gross wall area, opening deductions, net panel quantity, waste allowance and the number of squares. Then compare named product and profile, primed or factory finish, tear-off, sheathing repair rules, barrier, flashing, trim, paint or touch-up, haul-away, permit and inspection fees, and cleanup. Ask each bidder to attach the manufacturer product and finish warranties that match the actual products. A “30-year” label on a sales sheet is not enough to determine what repair work is paid later.

If the deciding question is vinyl versus fiber cement, the vinyl cost page provides a parallel per-square calculation and vinyl warranty extraction. The siding materials comparison covers broader material tradeoffs. This page is deliberately narrower: it lets a homeowner distinguish a basic unit model from a complete Portland re-side and read two named fiber-cement warranties as actual payment promises.

What we could not verify

All cited sources were reached during this review.

Questions to ask before you compare quotes

• Does the quote measure siding wall area or living area?
• Is the bid for primed material plus field painting or factory-finished siding?
• Are tear-off, flashing, trim and sheathing repair included?
• Who pays labor if a manufacturer replaces defective boards?

Sources

All retrieved 2026-09-29.

1. Homewyse, "Cost to Install Fiber Cement Siding"
2. Cornerstone Renovations, "How Much Does James Hardie Siding Cost in Portland?"
3. Allura, "Allura Lap Siding Submittal Sheet" (June 2026 PDF) (primary-document extraction)
4. Allura, "30-Year Transferable Limited Product Warranty" (PDF) (primary-document extraction)
5. James Hardie Building Products, "Hardie HZ5 Siding and Trim Products Warranty" (effective February 2024 PDF, distributor-hosted) (primary-document extraction)