As Mosby Building Arts’ registered architect, one of my responsibilities is to keep our team updated on changes in relevant building codes, and how municipalities have amended and enforce them.

Usually these changes are minor and incremental, coinciding with the adoption of new versions of the International Residential Code (IRC). This code updates every three years, and most Metro St. Louis municipalities are under 2009 or 2012 IRC. While St. Louis County proper has not yet adopted the 2015 IRC, the sections about smoke detector codes are already being enforced.

Hardwired Detector Rules for St. Louis County

By way of background a little history might be helpful. In the past, smoke alarms have been required in all sleeping rooms, outside of each sleeping area, and on each level. The code and its enforcement evolved to requiring all detectors to be hardwired (power) and interconnected (communication). The hardwiring requirement removes the risk of occupants not changing the batteries in their detectors. The interconnection requirement made it so that when one detector sounded an alert, all other detectors sounded as well. This is important when the origin of the fire is remote from the occupants.

In order to make this happen, wiring had to be run from a power supply and then to each detector.  This was often very challenging because it required opening up drywall which in turn required patching and painting after the install. These required changes added cost to even the simplest remodeling projects, which was an understandable frustration to many homeowners, remodelers and architects.

Changes to Smoke Alarm Codes

In November 2015 St. Louis County amended their ordinance and enforcement of the 2009 IRC to allow wireless smoke alarms and detectors, incorporating some aspects of the 2015 IRC.

The evolution of wireless technology means that an actual wire is no longer necessary for communication inter-connectivity.  The change of no longer requiring hardwired power to each (or any!) detector is a welcome surprise that lowers costs while putting the responsibility for battery maintenance back on the homeowners.

Overall, these changes are good for the homeowner and the remodeler as they free up money for projects with more lifestyle impact and return on investment. Unfortunately these changes only currently apply to municipalities whose building codes are enforced by St. Louis County or have adopted the 2015 IRC.

Can Your Home Go Wireless?

If you’re contemplating a remodel, and want to know if your municipality requires wired or wireless smoke alarms, check this list: The Code Enforcement Municipality Matrix

On this sheet, look for your town, and cross check it with the “Residential Code” column. If there is a grey box for your town it is likely they have adopted new sections of the 2015 IRC wireless code. If the box is white, you (or your remodeler) will have to contact that town directly to learn which smoke alarm codes they are currently enforcing.

Read the details of the updated St. Louis County IRC code for smoke alarms.

One of the many advantages of working with Mosby Building Arts for your remodeling projects is we (and me, specifically!) do all the research and procuring of building permits. We take care of all the code details that protect your safety and comfort. To collaborate on a project, call us at 314.909.1800 or contact us here.