The rules

Every controlled opening needs credential input, a way to leave without alarming, and position monitoring. Omitting the door position switch is the single most common shortfall in this trade: without it there is no door-forced and no door-held-open alarm, and the system silently becomes a lock rather than an access control system.

Where egress depends on a panic device, the latch must remain free at all times, so the locking function has to act on the panic device itself rather than on the frame. An electric strike releases the frame keeper and leaves the panic latch under electrical control, which is why a strike is not an acceptable substitute on this opening. This rule overrides quiet hardware preferences: acoustic comfort in an adjacent classroom does not outrank free egress.

Hollow metal frames accept a standard Grade 1 strike body with field preparation, and Grade 1 is the durability class appropriate to a school corridor. This is the default and it is deliberately the lowest priority in its conflict group, so any opening with a life safety, acoustic, or verification constraint is resolved by the rule that names that constraint instead.

A standard strike buzzes on release and clacks on relatch, which is disruptive immediately outside a classroom or an administration suite. The quiet alternative is continuous duty and draws roughly twice the holding current, so choosing it here is not free: it constrains the power supply calculation for the whole IDF, which is why this rule exists rather than leaving the choice to the installer.

A narrow stile will not accept a standard strike body, and the difference between a narrow stile and a standard stile changes both the device and the preparation. Selecting a strike here and discovering the stile at rough-in is a change order. Declining to select is the correct answer, and it is worth more to the estimator than a confident guess.

Frame material decides whether a strike is installable at all, and whether preparation is factory or field. Guessing hollow metal because it is the common case is how a bid absorbs a storefront.

Openings are allocated to panels by the closet that serves them, not by the building total, because a home run does not cross an IDF boundary. Rounding up rather than to nearest is deliberate: a partially populated panel is a normal condition, an under-provisioned one is a change order.

Latch retraction draws roughly thirty times its holding current at actuation. Fed from a shared access supply, that inrush browns out every other device on the branch, which reads in the field as intermittent reader failures that nobody connects back to the door. The supply must also sequence, so that retraction and any automatic operator do not start together. This is not a preference and it is not value engineering material.

The supply carries every device continuously and must additionally absorb the largest single actuation without sagging, which is why the sizing is total holding current with headroom plus the largest single inrush rather than a sum of inrushes: two strikes are not actuated at the same instant. Latch retraction openings are excluded from this calculation because AC-021 gives each of them a dedicated sequenced supply, so counting their inrush here would size the shared supply for current it never sees. Standby batteries are two 12V units in series because the supply output is 24VDC.

A low confidence entity flowing into the bill of materials as certain is how this category of product loses a customer permanently. The threshold is data in this rule rather than code, so a project that has hand verified its drawings can lower it.

A critical space is one where the district expects to be able to say who a person was, not merely that a person was present. Identification class is the resolution at which a face is usable, and it is a function of sensor resolution divided by the width of the scene at that distance, so it degrades with the square of the area a single camera is asked to cover. A space that receives detection class or worse will produce footage that shows an incident occurred and cannot support who did it, which is the specific failure districts complain about after the fact. The class is computed from the camera's own optics against the visibility polygon, not assumed from the presence of a camera on the plan.

This is separated from VS-001 deliberately. A space with a camera that underperforms is a design question about lens and placement; a space with no camera at all is a scope question about whether a device was omitted from the drawings. Those two findings go to different people and carry different money, so collapsing them into one rule would make the register less actionable.

This is the sentence that becomes a change order. 'BY OTHERS' with no named work and no named division tells a bidder that something in this area is not theirs, without telling them what, so every bidder draws the line in a different place and the low bidder is whoever drew it most generously. At award the question is settled by whoever has to open the wall. The finding is not that the work is missing; it is that the documents do not determine who has it, which under directive 2.4 is a flag rather than a quantity. A pre-bid RFI closes it for the cost of an email, and after award the same question is a negotiation.

A marker that names a division is a different finding from one that names nobody, and it points at us. 'BY OTHERS' reads as somebody else's problem right up until the sentence continues 'BY DIV. 28', at which point the work is electronic safety and security and the estimator reading the Division 8 section is the person who has to carry it. The common failure is symmetrical and expensive: the door hardware supplier reads the same sentence, agrees the work is Division 28, and neither party prices the rough-in. This rule wins its conflict group over SB-001 because the party is named, so the honest finding is a cross reference to confirm rather than an unattributed gap, and reporting both against one sentence would put the same money in the register twice.

Two sections requiring two different devices at one door is the argument half of section 2.4's 'a duplicate buy or an argument'. Only one device gets installed, so one of the two sections is unmet the day the door is hung, and which one is unmet is decided by whoever ordered first rather than by the design. The estimator's exposure is the difference between the two products plus the frame preparation that suits only one of them, and an electrified lockset and an electric strike do not share a frame prep. Note that a difference in wording is reported here as a conflict, because this rule compares what the sections say rather than guessing that two descriptions mean one product, and a seam where the two sections describe the device differently is worth reconciling before bid whether or not the descriptions turn out to name the same catalogue number. The severity is not blocking only because the fail state is not in question here; a conflict that also disagrees about fail-safe versus fail-secure on an egress opening is a life safety defect and belongs to the egress rules, not to this one.

This is the duplicate buy half of section 2.4's 'a duplicate buy or an argument', and it is the quieter of the two because nothing about it looks wrong on either sheet. Both sections are correct in isolation and both estimators price the device, so either the owner pays for two of them or, more often, one bidder assumes the other trade has it, deletes it, and is the low bidder for the wrong reason. It sits at medium rather than high because it is recoverable: the money is still in somebody's number and the answer is a scope conversation, whereas the states SB-022 and SB-023 report are money that is in nobody's number at all. It is deliberately separate from SB-020 because the reader is different. A duplicate is the estimator's question about what to carry, and a conflict is the project manager's question about which specification the submittal will be reviewed against.

This is the failure Part 3 describes when it says each package routinely assumes the other side covers the seam, caught in the act and provable from the documents rather than argued from silence. The door hardware section reads 'work of Division 28' and the access control section reads 'furnished under Division 08', and both writers believed they had assigned the work rather than declined it. At bid time nobody prices it, because each estimator reads their own section and correctly concludes it is not theirs. After award the two sentences are still there, which is why this is worth an RFI and not a phone call: the answer has to change a document. This rule wins its conflict group over SB-021 because counting assignments alone makes a circular hand-off look like two parties carrying one item, which is the opposite of what has happened, and reporting it as a duplicate buy would send an estimator to delete a line they never had.

Section 2.4 puts it plainly: neither means somebody eats it. Nobody has priced the item, so at award it is a change order or it is absorbed by whichever trade is standing closest to the opening when the gap is found, which in practice is the one already pulling cable. This is the most inferential rule in the family and its guards are the reason it is credible rather than noise. It fires only where both divisions are present in the document set and both were read, only on openings the drawings mark as controlled, and only where no third division was named either, because power taken from a Division 26 branch circuit is somebody's work and reporting it as unassigned would be wrong in the most embarrassing direction. It is deliberately separate from SB-022 even though both mean nobody carries the item, because one is an argument from two sentences a reviewer can open and the other is an argument from silence. Those two are answered differently, they fail differently, and Part 12 makes rule ids the thing published benchmark results cite, so collapsing them would make this family's precision uninterpretable.

Directive 2.4: where the documents do not determine something, produce a flag and not a guess. This is the state section 2.4's four outcomes do not name, and it is not the same finding as neither division specifying the work. Neither is a conclusion, reached after reading both sections and finding nothing; undetermined is the admission that one of them was not in the document set, or that the only sentence covering this work moves it to a party the documents decline to name. Reporting the second as the first would be Part 13's confident output where the honest output is a flag, and it would be the specific version of that failure this product can least afford, because a bidder shown 'nobody specifies the rough-in' on a package whose Division 08 section was never supplied will find the specification, find the assignment, and stop believing the register. Amendment A-006 made the same argument for SB-013 against SB-011, and this is the same distinction one gate later. The severity is medium rather than high because the finding is about our reading rather than about the documents: it tells a reader where to look, not what they will find there.

A supply sized to its nameplate with no headroom fails on the first hot afternoon with every door in use. The computed required and available currents are reported on pass as well as on fail, so a reviewer can see the margin rather than trust the verdict.

Authority UL 294; manufacturer supply derating guidance

Pre-bid action Carry an additional access power supply at this closet, or confirm the device schedule.

Devices at one opening on one branch must share an operating voltage or something is being fed the wrong supply. This is blocking because the failure mode is a destroyed device at energisation, not a performance shortfall, and because the resolution changes the bill of materials rather than the labour.

Authority UL 294; manufacturer device voltage ratings

Pre-bid action Resolve the device voltages at this opening before bid, or carry a second supply voltage at this closet.

Panel capacity is counted against the openings actually served from this closet. A shortfall found at commissioning is a panel, an enclosure, a circuit, and a return visit.

Authority CSI 28 13 00; manufacturer panel capacity data

Pre-bid action Add controller capacity at this closet before bid.

Beyond the copper limit the run needs a different topology: an intermediate closet, a fibre link, or a repositioned panel. Each of those is a design change rather than a longer cable, and discovering it during rough-in means the pathway is already installed.

Authority TIA-568 horizontal cabling distance; manufacturer device voltage drop guidance

Pre-bid action Confirm the serving closet for this opening, or price an intermediate closet or fibre link.

Standby capacity is specified in hours of supervised operation, and the required duration is jurisdictional. The computed runtime is reported so a reviewer can compare it against what this AHJ actually requires rather than against our default.

Authority NFPA 72 10.6.7 Secondary Power Capacity; project specification

Pre-bid action Confirm the required standby duration with the AHJ and adjust battery capacity.

On a designated egress path the locking arrangement must not defeat free egress, and a fail secure device on a panic protected opening does exactly that. This is blocking because it is a life safety defect rather than a cost item, and because it will not pass plan check.

Authority NFPA 101 7.2.1.5; CBC 1010.2.13 Electromagnetically Locked Egress Doors; CBC 1010.2 Door Operations

Pre-bid action Resolve the locking arrangement on this opening with the architect and the AHJ before bid.