Electrical Code - Garage

[TNsevier]

Hello all,
I am just looking for others thoughts, as I have never dealt with something like this before. I am located in eastern TN, and started a garage build a three car garage 4 months ago. The plan was to have a detached garage 30x50, that connected to my primary house with a breezeway. The garage is a separate service, due to my primary residence not having enough capacity left. Recently found out that having the breezeway connected between the house and garage is supposedly an electrical code violation. This is due to the fact that you cannot have two electrical services in one residence, and because the breezeway connects the house and garage, it breaks this rule. I find this a bit absurd, because if the garage did catch on fire (which I assume that is what the electrical code is focused on), it is only 10 feet away from my house, so it's going to catch my house on fire regardless. I even checked with my insurance company, and regardless of the breezeway this is considered a detached garage from their perspective. So I have some choices to make, obviously I cannot have the breezeway until the electrical inspection is complete. I could have this built on months later, and there would be no electrical inspection needed or required. It somewhat bothers me I have to bend rules to make this build finish. The breezeway was a big part of the garage plans, being able to park and bring stuff inside without the weather elements. Has anyone ran into this type of thing before? Just curious what others think.

 

[mike93lx]

That's the rule, and it's for good reason. Having two services to a structure can make it hard to make sure all power is disconnected in an emergency, for one.

Why not have the garage service be large enough to cover the whole thing, then feed the house from that? How small is the house service to not be able to support the shop?

Whats the rate and minimum charge on the shop service? You may find that having two services is expensive in the long run as they often are billed commercial and have a minimum charge that exceeds your power usage

 

[TNsevier]

Thanks for the response. The house is an older home, and has a 200amp service that has one breaker available. If I had not planned on having minisplits in the garage it may have worked out, but due to those needs, a new services was needed. The house electric is on the opposite side, compared to where the garage is built. It was mentioned the potential to do a 400amp service to the house, but the electrician said that was not common and didn't even want to price it.
I was told that I could build some kind of "firewall" between the garage and breezeway, but again that seems drastic.

 

[mike93lx]

Thanks for the response. The house is an older home, and has a 200amp service that has one breaker available. If I had not planned on having minisplits in the garage it may have worked out, but due to those needs, a new services was needed. The house electric is on the opposite side, compared to where the garage is built. It was mentioned the potential to do a 400amp service to the house, but the electrician said that was not common and didn't even want to price it.
I was told that I could build some kind of "firewall" between the garage and breezeway, but again that seems drastic.

The panel being full and the service being inadequate aren't the same thing. Tandem breakers or a subpanel can be used to open up room pretty easily and inexpensively.

Was a load Calc done to determine that the service size is actually too small? 200a is a lot of power and if you aren't all electric, I bet you have headroom

 

[TNsevier]

The house is all electric. It's a decent sized home, 2000+sqft, we have a barn and pool that also utilized for electric, so it's pretty utilized. The electrician didn't run a load Calc, he was fairly confident there wasn't enough wiggle room to make it work

 

[Chuckster in NJ]

1) As far as the building code goes, There MUST be a fire separation between the garage and house if there is a roof connecting the two.
2) Having TWO electrical services in a house is not a good idea (highly discouraged) BUT you can always ask for a "code variation"………. Not sure if they will give it to you but you never know unless you ask.
3) I have installed two services on a building in my 60 years in the trade BUT these were industrial services at different voltages on an existing building……….. The code says that these must be labeled 1 of 2 services and 2 of 2 services.
3) I highly suggest doing a service upgrade and "doing the job right" with one main service and a garage sub panel……. You will thank me later!

 

[TNsevier]

1) As far as the building code goes, There MUST be a fire separation between the garage and house if there is a roof connecting the two.
2) Having TWO electrical services in a house is not a good idea (highly discouraged) BUT you can always ask for a "code variation"………. Not sure if they will give it to you but you never know unless you ask.
3) I have installed two services on a building in my 60 years in the trade BUT these were industrial services at different voltages on an existing building……….. The code says that these must be labeled 1 of 2 services and 2 of 2 services.
3) I highly suggest doing a service upgrade and "doing the job right" with one main service and a garage sub panel……. You will thank me later!

What would a fire separation look like between a house and garage with a breezeway? I tried looking up some stuff on google, but wasn't finding a good visual to understand.

 

[mike93lx]

What would a fire separation look like between a house and garage with a breezeway? I tried looking up some stuff on google, but wasn't finding a good visual to understand.

Keep in mind, that is building code, not electrical code. A firewall doesnt change the two service limitation, at least as far as I know

 

[PCustoms]

Move the meter to the shop, put a larger panel in and feed SER cable to the house panel, making that a sub.

 

[Max]

I’ve seen breezeways where it is standalone and elevated a bit over the two roofs. This provides the dry area but since it’s standalone and not touching either building the buildings are not connected. Would something like that work for you?

 

[P0234]

Move the meter to the shop, put a larger panel on and feed SER cable to the house panel, making that a sub.

And avoid additional BS electric company fees on a second meter.

 

[TNsevier]

Keep in mind, that is building code, not electrical code. A firewall doesnt change the two service limitation, at least as far as I know

As far as I am aware, there is no building codes for where I am located. An electrical inspection is all that is required for my location.

 

[TNsevier]

I’ve seen breezeways where it is standalone and elevated a bit over the two roofs. This provides the dry area but since it’s standalone and not touching either building the buildings are not connected. Would something like that work for you?

That would certainly be a nice option, I don't think that would work for my setup, as both the garage and house are basically two stories tall, unless I am not understanding what you mean.

 

[mike93lx]

As far as I am aware, there is no building codes for where I am located. An electrical inspection is all that is required for my location.

There are always building codes. Lack of an inspection doesn't mean they don't matter.

Regardless, my point was that I do not believe a firewall does anything to help you, electrically.

 

[Max]

That would certainly be a nice option, I don't think that would work for my setup, as both the garage and house are basically two stories tall, unless I am not understanding what you mean.

I think you have it. That approach could work well for 1 story buildings but not for two.

I think that I’m in the camp of putting in a 400A panel in the garage and feed the house from the garage.

One last breezeway option would be to connect it to one building only and have a 6” or 12” gap at the other building. (Whatever the AHJ requires.). Then put a canvas or metal overhang on the other building to cover the gap.

 

[mike93lx]

I think that I’m in the camp of putting in a 400A panel in the garage and feed the house from the garage.

To add some detail for the OP, it would likely be a 320a service with two 200a panels

 

[acer66]

The panel being full and the service being inadequate aren't the same thing. Tandem breakers or a subpanel can be used to open up room pretty easily and inexpensively.

Was a load Calc done to determine that the service size is actually too small? 200a is a lot of power and if you aren't all electric, I bet you have headroom

2x

 

[Chuckster in NJ]

What would a fire separation look like between a house and garage with a breezeway? I tried looking up some stuff on google, but wasn't finding a good visual to understand.

Basically one layer of 5/8” sheet rock ran vertically under the roof area.…….. This will slow the spread of fire from the garage to the house.
You should also use 5/8” S/R on the wall of the garage facing the house.
This is a building code issue and has nothing to do with the NEC.

 

[TNsevier]

I think you have it. That approach could work well for 1 story buildings but not for two.

I think that I’m in the camp of putting in a 400A panel in the garage and feed the house from the garage.

One last breezeway option would be to connect it to one building only and have a 6” or 12” gap at the other building. (Whatever the AHJ requires.). Then put a canvas or metal overhang on the other building to cover the gap.

If funds were not an issue, I think would divert to the 400A panel in the garage option. I am just so far down the road, and the money saved for this project is almost gone. Hindsight is always 20/20.
I had spoke with the electrical inspector while he was at my house, and his focus was solely on fire hazard (one building catching on fire, and the other following suit.

The ideal of having a separation is interesting. I will have to dig into that and see what may be feasible.

 

[billconner]

As far as garage separation from house, at most 1/2" drywall on the interior of garage wall facing house and a heavy door. Depending on your jurisdiction, door may need to be self closing. At 10' I'm not sure you need that.

Depending what's in second story - if it's not only storage - codes would usually require 5/8 drywall on the ceiling. If it's an apartment or a bed room, definitely required and good idea. If an office or man cave, I suspect a lot of jurisdictions would let it go to though technically not compliant with code.

 

[dcg9381]

If funds were not an issue, I think would divert to the 400A panel in the garage option.

In my area, you can get 320A service, which is really a feed for 2 x 200A panels. As it's a single "source" of power, it doesn't violate NEC.

 

[billconner]

Here's the section from the IRC:
R302.6 Dwelling-garage fire separation.
The garage shall be separated as required by Table R302.6. Openings in garage walls shall comply with Section R302.5. Attachment of gypsum board shall comply with Table R702.3.5. The wall separation provisions of Table R302.6 shall not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.
Premium Code Insights :

TABLE R302.6DWELLING-GARAGE SEPARATION
SEPARATION MATERIAL
From the residence and attics Not less than 1/2-inch gypsum board or equivalent applied to the garage side

From habitable rooms above the garage Not less than 5/8-inch Type X gypsum board or equivalent

Structure(s) supporting floor/ceiling assemblies used for separation required by this section Not less than 1/2-inch gypsum board or equivalent

Garages located less than 3 feet from a dwelling unit on the same lot Not less than 1/2-inch gypsum board or equivalent applied to the interior side of exterior walls that are within this area
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

 

[billconner]

Here's the door to it,:

R302.5.1 Opening protection.
Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 13/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 13/8 inches (35 mm) thick, or 20-minute fire-rated doors. Doors shall be self-latching and equipped with a self-closing or automatic-closing device.

These are not fire walls in the normal sense. A firewall is a tested assembly - the whole wall, framing and all - that has been tested and proven to stop a fire from burning through for a specific time period. This layer of drywall is just a simple requirement that might add some minutes of protection or prevent a small fire or flame from igniting the common wall.

The stair from other than storage also has to be separated from the garage as similarly.

All subject to local jurisdiction amendments and interpretation. Sounds like not enforced where you live do primarily for your use and possibly insurance provider.

 

[TNsevier]

Here's the door to it,:

R302.5.1 Opening protection.
Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 13/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 13/8 inches (35 mm) thick, or 20-minute fire-rated doors. Doors shall be self-latching and equipped with a self-closing or automatic-closing device.

These are not fire walls in the normal sense. A firewall is a tested assembly - the whole wall, framing and all - that has been tested and proven to stop a fire from burning through for a specific time period. This layer of drywall is just a simple requirement that might add some minutes of protection or prevent a small fire or flame from igniting the common wall.

The stair from other than storage also has to be separated from the garage as similarly.

All subject to local jurisdiction amendments and interpretation. Sounds like not enforced where you live do primarily for your use and possibly insurance provider.

Thank you for this.
I think where I am struggling is the following. Where I live, out in the country, there are no building codes that are enforced. For example, if I build a new home, no one is required to inspect the foundation, or construction to a specific code. There are no ,permits that are pulled, aside from electrical, plumbing, and optionally HVAC. Now, if you lived in the city next to me, this is different, they have rules to follow in terms of permitted building construction.
I seem to be dealing directly with the electrical code issue of two services in one residence. The inspector considers this one residence if the buildings are connected in any way. There are no living quarters in the garage, or anywhere reasonable near the garage.
I think there are probably no good options for me. Upgrading the garage service, and then figuring out how to feed the house with that, or just forget the breezeway, or do the breezeway after the electrical inspection is done.
Feels like I could build a breezeway from non combustible material (steel maybe), and have that shown as a firewall, but I'm sure that would never fly.

 

[mike93lx]

Thank you for this.
I think where I am struggling is the following. Where I live, out in the country, there are no building codes that are enforced. For example, if I build a new home, no one is required to inspect the foundation, or construction to a specific code. There are no ,permits that are pulled, aside from electrical, plumbing, and optionally HVAC. Now, if you lived in the city next to me, this is different, they have rules to follow in terms of permitted building construction.
I seem to be dealing directly with the electrical code issue of two services in one residence. The inspector considers this one residence if the buildings are connected in any way. There are no living quarters in the garage, or anywhere reasonable near the garage.
I think there are probably no good options for me. Upgrading the garage service, and then figuring out how to feed the house with that, or just forget the breezeway, or do the breezeway after the electrical inspection is done.
Feels like I could build a breezeway from non combustible material (steel maybe), and have that shown as a firewall, but I'm sure that would never fly.

Again, you are mixing up building and electrical code. The dual service thing is not a building code, or fire issue.

Codes exist for a reason, but if you don't have inspections, no one can force you to follow them, however I don't think you are going to get much support here for ignoring it.

 

[TNsevier]

Again, you are mixing up building and electrical code. The dual service thing is not a building code, or fire issue.

Codes exist for a reason, but if you don't have inspections, no one can force you to follow them, however I don't think you are going to get much support here for ignoring it.

I am honestly not trying to ignore any codes. I don't want to be breaking any rules, otherwise I wouldn't think twice about just putting the breezeway up after the electrical stuff is connected.
I have this "fire issue" in my head, as that is what the electrical inspector had told me the issue was (in regards to have two connected structures with different service). Maybe he did not fully understand why these rules are in place. He is also the one that mentioned to me as having a "firewall" between the two structures to meet his inspection if we did connect the two buildings in some way.

 

[mike93lx]

Feels like he is reaching past the electrical inspection. Are you sure his purview is only that?

 

[TNsevier]

Feels like he is reaching past the electrical inspection. Are you sure his purview is only that?

100% certain - He is solely a state electrical inspector, nothing else.

 

[TNsevier]

Feels like he is reaching past the electrical inspection. Are you sure his purview is only that?

I guess I'm struggling to understand this, it must be going right over my head.
I get that two services are not allowed at one dwelling. Are you saying that the electrical code requirement should not be considering a detached garage connected in some fashion, one dwelling, or that that interpretation is more for the building code, and not electrical code?

 

[PCustoms]

100% certain - He is solely a state electrical inspector, nothing else.

What state?

Here the fire Marshal is the electrical inspector (if you are subject to an inspection)

 

[mike93lx]

I guess I'm struggling to understand this, it must be going right over my head.
I get that two services are not allowed at one dwelling. Are you saying that the electrical code requirement should not be considering a detached garage connected in some fashion, one dwelling, or that that interpretation is more for the building code, and not electrical code?

A detached building can have its own service. Once you join them, that ability goes away.

For fire code, you need separation between dwellings, as well as garage to living space.

Separate issues

 

[PCustoms]

I guess I'm struggling to understand this, it must be going right over my head.
I get that two services are not allowed at one dwelling. Are you saying that the electrical code requirement should not be considering a detached garage connected in some fashion, one dwelling, or that that interpretation is more for the building code, and not electrical code?

You have 2 situations:

1. per electrical code, you cannot have 2 services.inna single building (note there are likely exceptions)
2. An attached garage requires a firewall between the garage and house. This is likely just 5/8 type x drywall on the end wall/roof of the breezeway, but depending on the exact code and how close the house is you may need type X on that whole wall

 

[billconner]

If the buildings are separated by 10', I'd do what you suggest and finish electrical inspection and build breezeway. You could build it free standing and just add an "eyebrow" on each building to overhang gap. I wouldn't be terribly concerned.

A future buyer could have difficulty getting mortgage if it was shown not to be built to be code.

As far as electrical, just figure out the additional cost of a separate service versus one upgraded and feeding the other. (I would have a real load survey done. I changed my last house from a 60 amp to 200, clipped on an amp meter on feed, and rarely hit 30 amps.)

Not an electrician or engineer, but wondered if any way to interlock services that would satisfy inspector and didn't cost more than other solutions - like shunt trip breakers. I'm sure it's possible - just don't know cost or if it's ever acceptable.

 

[dcg9381]

Thank you for this.
I think where I am struggling is the following. Where I live, out in the country, there are no building codes that are enforced. For example, if I build a new home, no one is required to inspect the foundation, or construction to a specific code. There are no ,permits that are pulled, aside from electrical, plumbing, and optionally HVAC. Now, if you lived in the city next to me, this is different, they have rules to follow in terms of permitted building construction.
I seem to be dealing directly with the electrical code issue of two services in one residence. The inspector considers this one residence if the buildings are connected in any way. There are no living quarters in the garage, or anywhere reasonable near the garage.
I think there are probably no good options for me. Upgrading the garage service, and then figuring out how to feed the house with that, or just forget the breezeway, or do the breezeway after the electrical inspection is done.
Feels like I could build a breezeway from non combustible material (steel maybe), and have that shown as a firewall, but I'm sure that would never fly.

I live in a similar location. Outside the city. Very limited inspections.
But the deal is the county DOES have a construction standard. They just don't require permits or inspections. I'll bet your county has a similar standard and will refer to a specific version of the NEC.

I have a breezeway to a garage. It's just like any other "garage" structure, a fireblock (typically drywall) is required between the garage and the main structure of the house. No big deal. My breezeway is stick/brick.. Nothing special. Has a fireblock (drywall) at the peaks, just like any garage.

You have a barn/shop. What's the main feed for that? Any chance you can take that breaker down a notch and have enough "total power" to pass a load calc?

Alternately, give us a photo of your 200A load panel... Someone can swag the load, just as a double check.

 

[billconner]

You have 2 situations:

1. per electrical code, you cannot have 2 services.inna single building (note there are likely exceptions)
2. An attached garage requires a firewall between the garage and house. This is likely just 5/8 type x drywall on the end wall/roof of the breezeway, but depending on the exact code and how close the house is you may need type X on that whole wall

If type X is required, that's a jurisdictional amendment to the IRC.

 

[PCustoms]

If type X is required, that's a jurisdictional amendment to the IRC.

You're right, type x is only required on the ceiling below a habitable room per IRC.

I use it because the cost is negligible

 

[Miss the Pontiacs]

Would a dual meter socket (or an additional sub panel) in your home be he answer? I have done this both at the lake and in my residential dwelling. Then you simply run a cable between your two buildings. No need to take up valuable breaker space.
I have more than enough capacity but with the dual meter it is not necessary to have access to the panel. If you are wondering why such a large panel it was a Covid thing. This was what was available so what was installed at the time.
Or am I missing something?

 

[TNsevier]

What state?

Here the fire Marshal is the electrical inspector (if you are subject to an inspection)

Tennessee

 

[manwithtools]

In TN we are on the 2017 (10/1/2018) with TN amendments version of the NEC. Electrical inspections are performed by state deputized electrical inspectors under the jurisdiction of State Fire Marshall's office.

 

[TNsevier]

You have 2 situations:

1. per electrical code, you cannot have 2 services.inna single building (note there are likely exceptions)
2. An attached garage requires a firewall between the garage and house. This is likely just 5/8 type x drywall on the end wall/roof of the breezeway, but depending on the exact code and how close the house is you may need type X on that whole wall

So the issue becomes for me, that my garage is no longer considered a single building when it is "connected" by a breezeway to my house. If I'm following everyone correctly, the definition of what is considered connected, is not in the NEC stuff, but is a building code related item - which may be why others have suggested the electrical inspector may be overstepping just a little bit.
What I found interesting is my home insurance considers this a detached garage regardless of the interconnecting breezeway, which was partly the reason why I never had concerns for any "attached" garage requirements in the beginning. .