The Alarms the Permit Required and Nobody Quoted

Why this matters

A permit for interior work in an existing house often carries an obligation that has nothing to do with the work itself: bringing the whole dwelling's smoke and carbon monoxide alarms up to the requirements for new construction. The shop that knows this and leaves it off the quote has created a cost that somebody has to absorb, and it surfaces at the worst moment, at final inspection with the customer standing in a finished bathroom. This case follows one remodel from the quote to the conversation afterward, with the code reasoning at each point where the shop could have caught it.

The job

A remodel shop quoted a full hall bathroom renovation in a two-story house built in the 1970s, three bedrooms upstairs, a finished basement, a gas furnace and water heater, and an attached two-car garage. The scope moved one wall 18 inches to widen the shower, added a 20-amp circuit for a heated floor and a new exhaust fan, and replaced the fixtures. The shop pulled a building permit with electrical and plumbing sub-permits. The quote said nothing about alarms.

The house had two battery smoke alarms: one in the upstairs hallway, one at the bottom of the stairs on the main floor. Their date labels read 13 years old. No CO alarm.

What the permit triggered

The jurisdiction had adopted the 2021 IRC. Under R314.2.2 in that edition, as adopted, when alterations, repairs or additions requiring a permit occur in an existing dwelling, the dwelling unit gets smoke alarms located as required for new dwellings. Two exceptions matter for field work:

• work on exterior surfaces only (roofing, siding, windows and doors, a porch or deck) is exempt;
• installation, alteration or repair of plumbing or mechanical systems is exempt.

A bathroom remodel that only swapped fixtures under a plumbing permit would plausibly have sat inside the second exception. This one moved a wall and added a circuit under a building permit. It was an interior alteration, and the exception did not reach it. That reading is the shop's; the inspector's reading of the same exceptions is the one that counts, which is why borderline cases go in the shop's interpretation log. See related: Smoke and CO Alarm Requirements Your Permit Triggers, which owns the trigger rules across job types.

The CO section (R315.2.2 in the 2021 edition) has a parallel trigger for dwellings that have a fuel-burning appliance or an attached garage. This house had both. Its exceptions are similar to the smoke alarm exceptions but are not word-for-word the same, so read them in your adopted edition rather than assuming the smoke alarm list carries over.

The state layer sits on top. Some states add their own alarm requirements tied to permits, sale or rental through statute rather than the building code. California is one, through its health and safety code, and its rules can apply to work the IRC exceptions would exempt. Check your own state's statute as well as the adopted code.

Counting what new construction would require

New-dwelling smoke alarm locations under R314.3, as adopted, are each sleeping room, outside each separate sleeping area in the immediate vicinity of the bedrooms, and each additional story including basements. For this house:

• 3 bedrooms: 3 alarms
• upstairs hallway outside the bedrooms: 1 alarm (the existing one location)
• main floor: 1 alarm (the existing one location)
• finished basement: 1 alarm

That is 6 smoke alarms. Both existing alarms were past the 10-year replacement the alarm standards and their manufacturers require (NFPA 72, the consensus standard the IRC references for alarm installation, in the edition the code references), so all 6 were new. One CO alarm outside the sleeping area, upstairs, satisfies the CO location requirement here since no fuel-burning appliance is inside a bedroom or its attached bathroom. The hallway location can be one combination smoke and CO alarm, so 6 devices in total, one of them a combination unit.

Power and interconnection. New-construction alarms are hardwired and interconnected. For existing areas, R314.6 and R314.4, as adopted, carry exceptions where the alteration does not remove interior wall or ceiling finishes that would expose the structure, unless an attic, crawl space or basement gives access for wiring without removing finishes. The upstairs had attic access. This inspector accepted listed sealed 10-year battery alarms with wireless interconnection at all six locations, none of which sat in the bathroom work area. Many do; some read the attic clause as requiring hardwiring upstairs when access exists. That fork changes the labor by roughly a factor of three, which is exactly the kind of answer that belongs in a written interpretation before the quote.

How the final went

At final inspection, the inspector checked the bathroom, then asked to see the alarms. The tech showed the two old battery units. The correction notice listed smoke alarms per R314.2.2 and CO alarm per R315.2.2 and was signed.

The tech had heard of the requirement. The estimator had too. Each thought the other had handled it.

The conversation

The owner called the customer that afternoon. The shop had two facts: the requirement was real, and it was not on the quote. The customer had one: nobody had mentioned it.

OWNER:    The inspector passed the bathroom. He also
          wrote us up for smoke and CO alarms in the
          rest of the house.
CUSTOMER: We didn't touch the rest of the house.
OWNER:    No. The permit triggers it anyway. When you
          pull a building permit for interior work,
          the code has the whole house brought up to
          new-home alarms. Six alarms, one of them a
          combined smoke and CO, all on wireless
          interconnect.
CUSTOMER: Why is this the first I'm hearing of it?
OWNER:    Because we should have put it on the quote
          and didn't. That's on us.
CUSTOMER: So what am I paying for?
OWNER:    The alarms themselves you'd have needed
          anyway; yours are past ten years. We'll
          supply them at our cost and we'll put in
          the labor at no charge. We can do it
          Thursday, about three hours.
CUSTOMER: Okay. That's fair.

Three things made the call work. The owner led with the inspector's finding rather than with an apology, so the customer understood it was a requirement rather than an upsell. The owner said whose mistake it was in one sentence and did not argue the code. And the split followed the facts: the devices were a cost the customer would carry in any case because the existing alarms were expired, and the labor was the shop's failure to quote.

What the owner did not say matters too. The owner did not suggest skipping the alarms, did not ask the inspector to let it go, and did not offer to sign off without them. A permit cannot be finaled without the correction, and a house whose alarms were found expired by an inspector is a house the shop now knows about.

Installing them

The install was about 3 hours for one tech. Work on the ceilings was from a stepladder, footed on a level floor and used no higher than its marked top standing level, with a second person in the room for the stairwell location where the ladder stood on a landing. No circuits were opened, since every device was battery-powered and wireless. Each alarm was dated on its label with the install month, paired to the interconnect, then tested with its own test button. The tech then pressed the test button on one unit and confirmed all six sounded. Smoke and CO were never introduced to test them; the test button exercises the horn and the interconnect, which is what the inspector watches. The customer was shown the hush button, the end-of-life signal, and what the CO alarm's sound means: everyone out of the house, call 911 from outside.

The re-inspection passed.

What the shop changed

• The permit question goes on the estimate checklist. For any job needing a building permit for interior work in an existing dwelling, the estimator counts the alarm locations the new-construction rules require, compares them with what is installed and its age, and quotes the difference as its own line.
• When the exception is unclear, the estimator asks before quoting. Plumbing-only and mechanical-only permits often fall inside the exception; a jurisdiction's reading goes in the interpretation log by permit type. See related: The Code Interpretation Log SOP.
• The quote says it out loud. A line reading "Permit requires smoke and CO alarms throughout the dwelling per the adopted code" is in the template, priced or marked "not required, exception [reason]."

The general point the case carries

The job's scope and the permit's obligations are two different lists. The scope is what the customer asked for. The permit is a filing the shop made on the customer's behalf, and its obligations attach to the house as the code sees it. An estimator who prices from the scope alone will keep missing the second list, alarms being the most common item on it. This is not legal advice about who owes what when a quote omits a code requirement; the answer depends on the quote's terms and your state's contract law, and a disputed one goes to the shop's own attorney.

References

• International Residential Code, R314 (smoke alarms) and R315 (carbon monoxide alarms), 2021 edition, as adopted by your jurisdiction, including R314.2.2 and R315.2.2 for existing dwellings.
• NFPA 72, National Fire Alarm and Signaling Code, in the edition your adopted code references: alarm installation and the 10-year replacement.
• Your state's statute on smoke and CO alarms in dwellings, where one exists.
• See related: Smoke and CO Alarm Requirements Your Permit Triggers; Handling Inspector-Required Extras and Who Pays.