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Battery to Wired Smoke / CO Detectors

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  • Mar 31st, 2022 10:47 am
Oct 23, 2010
70 posts

Battery to Wired Smoke / CO Detectors

Hi all,

In the middle of a renovation for our house. We noted that all (3) smoke / CO detectors in the house were battery operated and need to be upgraded to wired to be in accordance with code.

Can anyone advise how much this would usually cost to have an electrician do? Is it a DIY-able project?

Thanks in advance.
8 replies
Sr. Member
Dec 21, 2020
651 posts
You don't NEED to upgrade them. They are grandfathered in so you can keep using battery powered ones.
Mar 14, 2022
392 posts
Outer GTA
Has your designer or an inspector from the building department suggested this?

Typically a Reno wouldn’t trigger this type of upgrade. It may be something you wish to voluntarily upgrade, however typically not required.
Deal Addict
Nov 30, 2011
1150 posts
RCLapCar wrote: You don't NEED to upgrade them. They are grandfathered in so you can keep using battery powered ones.
Unless it was called out as a required upgrade when he submitted for permit.
If not specified then they don't need to be changed.
BTW, Kidde makes a 10 year smoke/CO2 combi unit with a 10 yr battery.
Oct 23, 2010
70 posts
Unfortunately it was explicitly called out in our inspection report: Smoke alarms shall hard-wired, interconnected with battery back-up.

Is it possible to push back against the inspector and refuse to perform the upgrade?

The kicker is I upgraded the battery alarms to the 10 year smoke/CO units just last year..

I called around for a few places - seems like the going rate is $2500-$3800 (taxes in). This would be for 3 alarms on each floor, and one alarm in each bedroom. Naturally they don't do the drywall repair if a hole needs to be made.

Guessing nobody has tackled this on their own?
Deal Fanatic
User avatar
Oct 12, 2007
8320 posts
When we did our reno a dozen years ago, I was told by my GC that the permit required that any room being modified that the modifications (not the room) had to meet code. Since our reno involved getting rid of the stippled ceilings, the smoke detectors had to be removed to do that and they could not be reinstalled. Also, our reno was significant enough that it required a physical inspection and an occupancy permit. I was told that the inspector would not allow battery operated smoke detectors to pass - and that was in 2010.
I always upvote respectful/helpful posts wherever I encounter them.
Temp. Banned
Jun 24, 2015
7649 posts
all the electrician would be doing is running 14-3 between 3 junction boxes at most, and 14-2 from the closest one to your hydro panel. just hire the electrician to do the wiring only then install the smoke alarm yourself, its a peace of cake
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Drive an Escalade
Oct 23, 2010
70 posts
Makes sense. I have been quoted $3,300 + HST for the electrician to do this. Seems a bit high?
Deal Addict
Dec 27, 2007
4447 posts
All depends on the routing. I have done it before and it’s not bad. Take your time on the weekend and then the weekend after just patch up drywall, mud and tape and your good to go. It’s almost all labour work
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