SB 721 Product Substitution Process for Balcony Repair

A product substitution is a formal request to install something different from the product named in the project specification. On SB 721 and SB 326 balcony repair projects, the spec usually names a specific waterproofing assembly as the basis of design. A named coating, membrane, or flashing system that anchors the fire-classification path and the warranty structure the owner is paying for. If the general contractor or waterproofing applicator wants to install a different product, they have to document equivalence, get it reviewed, and secure written approval before ordering material.

The process has three layers. The architect of record (AoR) evaluates technical equivalence. The owner consents to any schedule or cost impact. The local building department. The Authority Having Jurisdiction, or AHJ . Validates code compliance when the substitute changes anything on the permitted drawings. All three have to line up. A substitution that the AoR approves but the AHJ later rejects is worse than no substitution at all, because material has usually already been ordered.

Balcony repair specs name a specific product because the choice drives several downstream decisions that are hard to unwind: the ICC-ES evaluation report, the fire classification, the warranty, the applicator-certification requirement, and in many cases the flashing and drainage details drawn on the sheets. A "basis of design" product is shorthand for all of that. Substituting it means re-verifying every one of those links.

This page is a process reference for the contractor and specifier side. For the parent compliance framework, see the California Balcony Inspection Law (SB 721 & SB 326) overview.

Contractors request substitutions for practical reasons, not because they want to second-guess the specifier. The most common drivers:

• Regional availability. The specified product ships from a distant region and the lead time blows the repair-completion window.
• Lead time. The basis-of-design product is backordered and the inspection report has a deadline the owner is trying to meet.
• Warranty structure. The contractor has an existing relationship with a different manufacturer that offers a joint material-plus-labor warranty on this assembly class.
• Substrate compatibility. The as-built substrate (gypsum-concrete topping, older plywood, existing coating residue) is incompatible with the specified product and the alternative is rated for the condition.
• Applicator familiarity. The approved applicator pool for the specified product is thin in the project market, or the contractor has a long-standing certified applicator for a comparable system.
• Cost. The alternative is less expensive and the savings can flow to the owner as a deductive change order.

Cost-driven substitutions are the touchiest of the six. The rule under standard contract language is that any cost savings from a contractor-initiated substitution belong to the owner, not the contractor, unless the substitution request and the Change Order specifically say otherwise. Keeping the delta is a common reason substitutions get rejected or unwound after the fact.

Whether a substitution is even allowed. And if so, how to submit one. Is answered inside the specification itself. The relevant language usually lives in two places: the product section (Division 07 for waterproofing) and Division 01 (general requirements). The product section tells you what the specifier wants. Division 01 tells you how to propose something else.

Basis of design

A "basis of design" (BoD) product is a specific named product that establishes the performance standard for that scope. It is not automatically a mandate. A BoD listing usually means the specifier expects a comparable product. One that equals or exceeds the BoD on every listed performance criterion. To be considered. The mechanics of proving equivalence live in Division 01.

"Or approved equal" and "comparable product"

These are the two phrases that open the door to a substitution. Both mean roughly the same thing: the specifier will consider a product that functions as well as the named product in all essential respects. The exact definition of "comparable" is whatever Division 01 says it is. Typically a point-by-point match on every listed property, plus equivalent warranty and equivalent installed performance.

"No substitutions" / "sole source"

If the spec says "no substitutions" or "sole source," the specifier is closing the door. Comparable products are not considered at all. If a contractor still believes a substitution is warranted, the only path is a formal spec amendment signed by the AoR. Effectively a design change, not a substitution.

Division 01. The procedure

The substitution procedure itself is in Division 01, usually Section 01 25 00 Substitution Procedures or 01 60 00 Product Requirements. That section tells you what form to use, what documentation to attach, how many days before the material is needed the request has to be submitted, and what happens if the request is late. For pre-award substitutions, the equivalent language is in the Instructions to Bidders.

For broader context on the contract language that governs substitutions, AIA A201–2017 § 3.4.2 is the industry-standard clause: the owner and architect will consider a substitution request after the contract is executed, and any substitution requires owner consent, architect evaluation, and a Change Order or Construction Change Directive.

Substitution approvals involve four parties on a typical SB 721 / SB 326 balcony repair. Each has a distinct role. Skipping any one of them is the fastest way to get a substitution unwound after material has been ordered.

Architect of Record (AoR). Evaluates

The AoR is the licensed architect whose seal is on the permitted drawings. The AoR is the primary technical reviewer. Four standard response options after review: Accepted, Accepted with Notes, Not Accepted, and Received Too Late. The AoR's job is to confirm the substitute matches the BoD on every performance criterion cited in the spec, that warranty parity holds, and that aesthetic and detailing impacts are disclosed.

Engineer of Record (EoR). Evaluates when structural is affected

On balcony repairs with framing replacement, connector changes, or load-path modifications, a structural EoR sealed the structural drawings. Any substitution that touches dead load (a heavier coating assembly, for example), fastener type, or connector detailing routes through the EoR in parallel with the AoR.

Owner. Consents

The owner is the party to the construction contract. The owner weighs the technical equivalence against schedule and cost, and is the final decision maker on whether the substitution is accepted. Owner consent is separate from the AoR's technical acceptance. An AoR can accept a substitute that the owner then declines for cost or schedule reasons.

Authority Having Jurisdiction (AHJ). Validates

The AHJ is the local building department (or, on state-funded work, the Division of the State Architect). The AHJ has independent authority to accept or reject the substitution on code-compliance grounds. The AHJ typically only engages when the substitute changes something on the permitted drawings: fire classification, structural load path, code-path compliance. If none of those are affected, AHJ re-review is usually not triggered.

A complete substitution submittal is not a cover letter with a data sheet stapled to it. Reviewers reject incomplete packages without reading them, and a late resubmittal often lands outside the contract-specified window. The baseline package has seven sections.

1. Cover letter

• Project name, address, and permit number (if issued)
• Contract section, article, and paragraph being substituted
• Basis-of-design product ID (manufacturer, product name, model) as named in the spec
• Proposed substitute ID (manufacturer, product name, model)
• Stated reason for the substitution
• Impact on the contract sum (cost delta, savings flowing to owner)
• Impact on the contract time (schedule delta)
• Contractor certifications: functional equivalence, disclosed installation changes, warranty equivalence, trade coordination

2. Side-by-side comparison table

The core of the submittal. A point-by-point match on every property the spec lists. The template field list is in the next section. Leave the values blank on this page. The contractor fills them in from the manufacturer data for the specific BoD and proposed products on their project.

3. ICC-ES evaluation report

The full ESR PDF for the proposed product, not a summary. For walking-deck waterproofing, the relevant acceptance criterion is usually ICC-ES AC39. For a substitution to be a true equivalent under an ESR-referenced spec, the substitute has to be evaluated under the same acceptance criterion and the same code provisions and conditions of use as the BoD product.

4. Warranty documents

The actual warranty document, not a marketing summary. Warranty term (years) and scope (material-only, labor-plus-material, or system warranty) are the two fields that drive acceptance. A shorter or narrower warranty than the BoD is a common rejection reason.

5. Applicator credentials

Manufacturer certification for the applicator installing the proposed product. Include the certificate, any training records required by the manufacturer's QA program, and evidence the applicator has installed this system at the scale of the project. Some manufacturers require a pre-start site visit, periodic inspection during installation, and a completion letter to the architect. Surface any of those obligations in the submittal so the schedule can accommodate them.

6. References

At minimum three prior projects using the proposed product, in the same application class (balcony / walking deck / roof deck over occupied space), with contact information the AoR can actually reach. References matter when the substitute is from a manufacturer the specifier is unfamiliar with.

7. Attachments

• Manufacturer product data sheets
• Safety data sheet (SDS)
• Test reports referenced in the comparison table
• Physical sample (if specified)

The side-by-side comparison table is where an equivalence claim stands or falls. Structure it as three columns: property, basis-of-design value, proposed substitute value. Every row the spec lists as a performance requirement has to be present, and the proposed value has to equal or exceed the BoD value. The table below is the field list only. A template. Values are filled in from the specific manufacturer data for the BoD and substitute products on the project.

Timing is where most otherwise-valid substitutions die. Submit the request early. Before material needs to be ordered and before the installation activity shows up on the critical path. If the AoR responds Received Too Late, the BoD product is what gets installed regardless of the technical merits.

Form template

CSI Form 13.1A is the de-facto industry template for substitution requests after bidding. CSI Form 1.5C covers substitutions during the bidding period. Neither is mandated by AIA A201. Division 01 on a specific project can prescribe a different form, and when it does, that form controls. Read Division 01 before reaching for a CSI template.

Architect review window

A 30-day architect review window is a common baseline in Division 01, though the actual number varies by project. Plan the submittal backward from the material order date: architect review time, plus owner consent time, plus any AHJ re-review if the substitute affects the permitted drawings, plus the manufacturer's lead time on the substitute itself.

Public works reference point (SB 721 / SB 326 do not use this)

California public works projects operate under Public Contract Code § 3400, which requires an "or equal" opportunity and sets a statutory default of 35 days after contract award for the substitution request unless the spec specifies a different window. This is worth knowing as an industry reference point. It does not apply to SB 721 or SB 326 projects, which are private-owner work. The contract- specified timeline in Division 01 controls on a private balcony repair.

The AHJ. The local building department. Usually does not re-engage on a straight product substitution. AHJ review is triggered by changes that affect what is on the permitted drawings or the code path. Four categories to watch for:

• Permitted drawings must be revised (the substitute changes a detail, thickness, or assembly drawn on the sheets).
• Fire-resistance rating changes (Class A vs. Class B, or a change in tested assembly).
• Structural load path changes (dead-load delta triggers EoR re-review, which can flow to AHJ).
• Code-path changes (the substitute is approved under an alternative method rather than the prescriptive code path originally permitted).

Alternative Materials and Methods Request (AMMR)

When a proposed substitute does not literally match the prescriptive code path but can demonstrate equivalent performance, the mechanism is the Alternative Materials and Methods Request (AMMR) under CBC § 1.11.2.4. The request goes to the building official, is approved case-by-case, and applies only to the permit it was submitted under. The San Mateo AMMR form is a representative example of what CA AHJs ask for. Expect supporting engineering analysis, ICC-ES or equivalent third-party evaluation, and a written statement of equivalence from the design professional of record.

Most rejected substitutions fail on documentation, not on the product. Six recurring patterns:

• Late submission. The request lands outside the Division 01 window and the AoR returns it as Received Too Late.
• Incomplete point-by-point comparison. The table skips properties the spec listed, or fills them with "meets or exceeds" instead of actual values. Reviewers cannot accept an equivalence claim without the values.
• Missing or non-equivalent ESR. The substitute lacks an ICC-ES evaluation report, or has one evaluated under a different acceptance criterion than the BoD.
• Warranty mismatch. Substitute warranty is shorter, narrower, or conditioned on applicator certifications the project applicator does not hold.
• Fire-rating non-equivalence. The substitute has an ESR with a Class A rating on one assembly and a Class B rating on another, and the submittal does not identify which assembly is being proposed for a Class A specification.
• Cost savings retained by contractor. Deductive change order missing, or the substitution request is structured to hold the delta on the contractor side of the ledger rather than flowing to the owner.

A few California-specific reference points that come up on balcony repair substitutions. Read the scope carefully on each. Most do not apply to a private SB 721 / SB 326 project directly.

Public Contract Code § 3400 (public works only)

PCC § 3400 requires CA public-works specs to include an "or equal" provision when they name a specific product, with narrow exceptions for field-test matching, match-existing, single-source, and emergency conditions. The legal equivalence test is whether the substitute "functions as well, in all essential respects, as the specified equipment." This statute does not govern SB 721 or SB 326 projects. Those are private-owner work. PCC § 3400 is referenced here because it is a widely-known equivalence standard that contractors often use as a template.

DSA Construction Change Document (state-funded only)

The Division of the State Architect oversees K–12, community college, and state-funded building projects. On DSA-approved projects, material substitutions run through the Construction Change Document (CCD) process (form DSA 140, governed by DSA Interpretation of Regulations A-6). Typical SB 721 and SB 326 projects on privately-owned apartments and HOA condos are not DSA jurisdiction and do not use the CCD process.

AMMR (applies to all California AHJs)

The Alternative Materials and Methods Request under CBC § 1.11.2.4 is the mechanism that does apply to SB 721 / SB 326 when a substitute requires AHJ-level code-equivalence sign-off. See the When AHJ Gets Involved section above.

Title 24 energy code

Balcony waterproofing substitutions do not typically trigger Title 24 energy-code review because walking-deck coatings are not usually part of the thermal envelope. The exception is a roof deck over occupied space where the coating is part of a thermal-envelope detail. If it is, confirm with the AoR before submitting.

When a substitution comparison table includes AC39-evaluated walking-deck systems, Deck Flex (ICC-ES ESR-3672) is one system contractors may include. See the Deck Flex brand page for the current evaluation-report scope, or the Deck Flex SB 721 / SB 326 reference for manufacturer-depth product guidance. Whatever system is named on a specific project, the same equivalence workflow on this page applies.