CSI Form 13.1A Construction Substitution Request: Filing and Approval

CSI Form 13.1A is the Construction Specifications Institute’s standard one-page form for requesting a material or product substitution after a construction contract has been awarded. You fill it out by identifying the project and the exact specification section affected, describing the proposed replacement product, attaching a point-by-point comparison against the specified product, disclosing cost and schedule impacts, and signing the certification block. You submit it through whatever delivery method the project’s Division 01 requirements prescribe, and you do it before the deadline the specification sets — because a late request is rejected without any technical review at all.¹

Confirm You Need 13.1A and Not a Different Form

CSI publishes two substitution forms, and timing decides which one applies. Form 13.1A is for substitutions proposed after contract award, which is the situation most contractors face when a specified product becomes unavailable, jumps in price, or has an unreasonable lead time. Form 1.5C is for substitutions proposed during the bidding period, before any contract is signed.² The two look similar, but approved bidding-phase substitutions go out to every bidder as a formal addendum so all bids price the same materials.³ A 13.1A approval flows through the change order process between the contractor and owner.

Not every alternative product triggers a substitution request. Where a specification names a product followed by “or approved equal” language, you may be able to submit a simpler equivalency demonstration. Where the specification is proprietary — one named product, no alternatives — any deviation requires the full 13.1A. Check your Division 01 requirements, because some owners treat “or equal” proposals as substitutions and demand the same form either way.

Where to Find the Form

The form is typically included in the project manual under Division 01, Section 01 25 00 (Substitution Procedures). Some projects allow a contractor-generated form carrying the same information, but using the standard CSI format avoids unnecessary pushback from the design team.⁴

How to Fill Out CSI Form 13.1A

Project and Specification Identification

The top block asks for the project name, the architect or engineer’s project number, the contract designation, and a substitution request number you assign sequentially so the design team can track multiple requests. Below that, you identify the exact specification section affected: the MasterFormat section number, section title, page number, and article or paragraph reference.⁵ Precision matters. If you cite the wrong section, the architect has to hunt for the original requirement, which delays the review and signals that you have not carefully read the specification.

Proposed Substitute Details

The next section captures the replacement product’s identity: manufacturer name and address, trade name, model number, and installer’s name and contact information.⁵ The form also asks for product history and scope — how long the product has been on the market, where it has been installed in similar applications, and whether its use would require changes to other parts of the work.

That last question trips up a lot of contractors. If your proposed roofing membrane has a different flashing detail than the one specified, the change cascades into the sheet-metal subcontractor’s scope. Acknowledge it on the form. Hiding it guarantees trouble later.

Point-by-Point Comparative Data

This is where most substitution requests are won or lost. The form requires a point-by-point comparison between the specified product and the proposed substitute, and the form labels the attachment “REQUIRED BY A/E” — not optional, not helpful, required.⁶ Cover every performance characteristic the specification addresses: fire rating, load capacity, thermal resistance, dimensional tolerances, warranty terms, available finishes, anything else the spec calls out. Present the data as a table or side-by-side layout so a reviewer can scan for differences in seconds. If the substitute falls short on any metric, address it directly rather than hoping nobody notices.

Supporting Documentation

The form has checkboxes for supporting attachments: drawings, product data, samples, test reports, and other reports.⁶ Check every box that applies and attach the actual documents. Independent laboratory test reports carry more weight than manufacturer marketing literature. If the project has sustainability goals or is pursuing LEED certification, include documentation showing the substitute meets the same environmental credit thresholds as the original product. A substitution that jeopardizes a LEED credit will be rejected even if the product is technically superior on every other axis.

Cost and Schedule Impact

State the financial impact of the substitution: the dollar amount of savings or additional cost to the owner, and whether the change adds or deducts days from the schedule.⁵ Be honest with the numbers. Under AIA A201-2017 Section 7.3.8, when a substitution produces a net decrease, the credit to the owner is based on the actual net cost as confirmed by the architect. The contractor does not automatically pass through the full price difference, because overhead and profit on the original scope are treated as costs already incurred.⁷ When the substitution produces a net increase, the overhead and profit allowance is calculated on the net increase only.

Contractor Certification and Signature

The certification block at the bottom is the section with real legal teeth. By signing, you certify that the proposed substitute is equal or superior to the specified product, that the same warranty applies, that replacement parts and maintenance service are available, and that the substitution will not adversely affect other trades or delay the schedule.² You also agree to pay for any changes to the building design caused by the substitution, including the architect’s redesign fees. Factor those costs into your savings calculation before you submit.

The certification also means you own the consequences if the substitute fails. Under AIA A201-2017 Section 3.4.2, the contractor assumes all liability for changes or additional work needed to accommodate an approved substitution, even if additional costs surface after installation.⁸ Owner approval does not shift that risk.

How to Submit the Form

Your project’s Division 01 General Requirements will specify the delivery method. Many projects route substitution requests through a digital project management platform such as Procore or Newforma, which timestamps the submission and creates an automatic record. Some projects accept formal email if you follow a prescribed subject-line convention. Others require wet-ink signatures. Whichever method applies, keep proof of when you submitted, because that timestamp matters if a deadline dispute arises later.

Watch the Deadline

Every project sets its own deadline for substitution requests, and missing it is the single most common reason requests get rejected without review. Deadlines are measured from the notice to proceed and vary: some projects allow as few as 20 days, while others extend the window depending on the procurement schedule. Your contract’s Section 01 25 00 will state the exact cutoff. The form itself includes a review designation reading “Substitution Request received too late — Use specified materials,” and architects use it freely.¹ If you already know a substitution may be needed, start gathering product data and preparing the form as soon as the contract is executed, not when the material hits the critical path.

What the Architect Does With Your Form

Once the architect or engineer of record receives a complete form, they evaluate whether the proposed substitute meets the design intent. If your submission is incomplete, the review clock does not start; the architect will send it back and ask for the missing data. The architect then marks the form with one of four designations:

Substitution approved. The substitute is accepted and the contractor proceeds with submittals under the project’s submittal procedures.
Substitution approved as noted. The substitute is accepted with specific conditions. Read the notes carefully; failing to comply with a condition can turn an approval into a default.
Substitution rejected. The contractor must provide the originally specified material.
Substitution request received too late. The contractor must provide the originally specified material regardless of the substitute’s technical merit.¹

A rejection is not necessarily the end. If you believe it was based on incomplete information, you can resubmit with additional documentation. A second submission on the same product without new supporting data will get the same result and annoy the design team in the process.

Why Requests Get Rejected

Most rejections trace to three preventable problems. First, the point-by-point comparative data is missing or incomplete. Architects will not do your homework: a product data sheet without a mapping to the specified product’s requirements goes straight to the rejection pile. Second, the request arrives after the submission deadline. Third, the form is mislabeled or references the wrong specification section, so the reviewer cannot locate the original requirement. A smaller but persistent category involves substitutes that perform well technically but would force changes to adjacent work that the contractor never acknowledged on the form.

After Approval: Change Order and Records

An approved substitution does not become part of the contract automatically. Under AIA A201-2017 Section 3.4.2, substitutions require the owner’s consent and must be formally incorporated through a change order or construction change directive.⁸ Until that paperwork is executed, the substitution is not officially in the project record, which means it will not appear in final inspection documentation or warranty tracking. Do not install the substitute material before the change order is signed, no matter how confident you are in the approval.

The approved form and change order should be filed in the project record alongside the original submittal. During closeout, inspectors and commissioning agents will compare installed materials against the approved substitution list. If a product shows up in the building that matches neither the original specification nor an approved substitution with a corresponding change order, you are looking at a potential removal-and-replacement directive at your own cost.

1
Maryland Stadium Authority. CSI Form 13.1A Substitution Request
2
City of Oswego. CSI Form 1.5C Substitution Request During Bidding
3
Southern Methodist University. Product Substitutions
4
University of Colorado Anschutz Medical Campus. Section 012500 – Substitution Procedures
5
The AIA Trust. CSI Form 13.1A Substitution Request
6
ClarkDietrich. Substitution Request After the Bidding/Negotiating Phase
7
AIA Contract Documents. Contractor’s Overhead and Profit on Deductive and Net Increase Change Orders
8
University of Wisconsin. AIA A201-2017 General Conditions of the Contract for Construction