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Old 12-06-2019, 01:55 PM   #1
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5 Car Garage Conversion


Hi everyone,

New here and to homeownership, and what a ride its been so far. I apologize if this is redundant, and I don't have photos at the moment, but here is our predicament:

-We have a 5-car garage for a 2000 sqft house (the previous owner was a car collector).
-The house is calling for a family room/second living area and potentially another bedroom. As is, the garage is heated and cooled, and has painted/finished drywall all around apart from the garage doors.
-No idea if the footings (all updated in 2004) are currently able to support garage door conversion to normal exterior walls with siding or not.
-We would like to convert the larger part of the garage, leaving the 2-car garage with the automatic door as is, cutting it off with drywall.

Questions:
1- Is there a way to do this job without going through the proper approval from town building dept? Obviously this depends somewhat on the town, but I can tell you ahead of time they are stringent, not loose. My fiance's father is a construction manager for Toll Bro's, so it seems to me we could do most of the work ourselves. At the very least the drywall and flooring. I may have answered my own question.

2- What kind of cost am I looking at? I know the flooring by itself will be a few grand depending on what we go with. What does it cost do dig out and pour new footings to be up to code for new exterior walls replacing the 2 manual garage doors? Plus the walls themselves and siding...

3- What factors have I not considered? I'd appreciate any and all constructive advice I can get.

Thanks
Noah
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Old 12-06-2019, 02:05 PM   #2
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Re: 5 Car Garage Conversion


You'd be required to get a permit. If you don't get a permit and get caught they could make you undo all the work. Minimum fine is double the permit cost.


If the footers are adequate for the garage there shouldn't be any issue for the conversion. Sometimes there is no vapor barrier under a garage slab and that could be an issue.
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Old 12-06-2019, 02:14 PM   #3
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Re: 5 Car Garage Conversion


I wouldn't think of doing it without consulting with the city.
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Old 12-06-2019, 03:09 PM   #4
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Re: 5 Car Garage Conversion


Asking us how to do the work without proper approval isn't really fair, many of us are highly skilled and honest contractors. Besides the potential of being discovered the work you want to do can be far more extensive than you expect. Major renovations often require new work to meet the latest codes.

If permits were pulled for the 2004 update those plans should be on file and may provide valuable information. They may also have the architect's name providing a place to start.

You asked for an estimate which I can't do, but from experience my GUESS would be $50K. I've done much smaller projects at $20K.

As for going without permits that begins a long line of deception and many phases of this project will reference those permits and any sub-contractor that has a dispute will have you over a barrel. Remember the Quote "Oh, what a tangled web we weave, when first we practice to deceive!" (Sir Walter Scott, 1808).

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Old 12-06-2019, 04:49 PM   #5
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Re: 5 Car Garage Conversion


Iím with the other guys, pull your permits.

I will mention 3 items you didnít.

1) your electrical requirements in dwelling areas require more than you find in a typical garage. Additional items, if you have them) such as heavy electonics, entertainment, refrigeration (bar area?), etc can further drive the electrical needed.

2) windows. There isnít much glazing needed in a garage. There are requirements in a dwelling area, and a lot of people want to exceed the minimums for bright spaces. So, you will probably be restructuring the existing back wall, in addition to the front. (Iím assuming the 3 bays to be converted are nearest to the existing living area.)

3) What is your existing floor height in the living area ? How far is it above the garage floor ? Do you intend to have the new area match it ?
You may need intermediate support walls poured if you are matching floor height. (to keep your joist sizes down with width of the addition, assuming the current slab is left in place)
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Old 12-06-2019, 05:07 PM   #6
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Re: 5 Car Garage Conversion


First, let me say Noah as a car guy this is just utter blasphemy, get the pitchforks! There are good people all across this country in therapy because they can't have the garage space they desire. Now that I've said my piece:

Permitting: Your assessment is based on your SF of occupiable (conditioned) space vs. garage vs. basement and they probably have a picture of the front of house. Reducing the number of stalls, adding a bedroom, family room, or windows to the front elevation changes that and your life will be much easier going through the proper procedure. Yes, your taxes will go up with more occupiable SF.

Resale: The modern standard in a certain price range is a 3 car garage. Two for cars, one for stuff, with flexibility for the future kid/in-law car. You haven't given much info on the house or your location, but it helps keep value. Also, if the conversion is done poorly/cheaply, and looks like a conversion, it could have negative impact on your value (see below).

Construction items to think about:
- In terms of foundation, nothing different should be needed. However, depending if you add floor joists or for some reason the slab is inadequate, they may require a thickened slab at the new separating wall.
- Your garage slab should be at least 6" lower than the house floor. The floor still needs that 6" height difference at the new interior wall door access.
- The exterior wall infill and interior walls will be sitting level with the existing garage slab and closer to the grade (no stem wall). Address water/bug issues.
- The garage slab slopes either to the door or a drain. Frame a level floor.
- The driveway slab/asphalt goes right to the wall. Remove at least some for landscaping.
- The layout should address a higher ceiling if it has one, the attic access, the exterior man door, and electrical panel if out there. Usually the garage man door is at the back of a kitchen or laundry room. This is not the best solution for access to a family room or bedroom. Consider renovation of the house. Also, large rooms require lots of light + ventilation (big windows), which your garage did not.
- The existing HVAC (mini-split or hung unit gas/infrared heat, maybe radiant floor) should be separate from the house, and is probably inadequate for multiple occupiable rooms. Would you keep it separate by removing it from the remaining 2 stalls, or connect new rooms to the house HVAC?
- The existing electrical probably can't be reused (adding load to existing circuits, high receptacles, general lighting, tool subpanels/disconnects) beyond adding for new layout, so assume a gut job.

Edit: this may repeat some info by Oso while I was brooding, er I mean typing

Last edited by 3onthetree; 12-06-2019 at 05:11 PM.
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Old 12-06-2019, 10:42 PM   #7
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Re: 5 Car Garage Conversion


I think the big parts of the budget will be electric/heat. If existing hvac can be rerouted or needs a new system. Depends on the existing capacity, although hvac for few cars probably was calculated for lower requirement than for people. If you convert with super-insulation in mind, maybe your hvac for the house will heat the addition. You can figure this out with heat/cool calculator (or hvac calculator). It is possible that the hvac system you have has more capacity than you really needed.
For electric, what amp main panel do you have? If 200 amp panel, probably has lots of extra spaces to add electric. Living quarters requirements are different. You'll also need smoke alarms and egress windows for the bedrooms. Different building rules for the wall that separates the garages from the living spaces.
I don't think you will need a new foundation. You can add the wall to block off the existing garage doors but add a low concrete wall (16" or so?) so you don't build with wood lumbers that close to the ground. Add some sort of drain around the perimeter and good gutter system.

Slab isn't a good floor for living spaces. You may want to add joists to the slab to raise the floor. Something like this needs good venting under the floor.
I don't think the project has to be a high cost, esp the relative who knows and can do all the work. But with 2K house, do you need a bigger house? Your property tax will go up. But I agree with everybody about getting the permits. This is especially important if you want to sell the house. By usual real estate practice, which will involve lawyers no matter how hard you try to do without, you need town's permit to sell. House will be inspected at that time. If you have no permit, you will be penalized by both the town and any potential buyer. Since you didn't buy the house without knowing about that garage, you should do it by the book and invest for the future.
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Old 12-07-2019, 04:55 AM   #8
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Re: 5 Car Garage Conversion


Quote:
Slab isn't a good floor for living spaces.
While a wood framed floor is nicer many homes in the south are built on a slab and most folks are fine with that.
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Old 05-24-2020, 07:54 PM   #9
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Re: 5 Car Garage Conversion


Looking back at this original post of mine, I'm a little disappointed in myself for ever considering trying to do this illegally. Definitely appreciate all of your advice.

"If permits were pulled for the 2004 update those plans should be on file and may provide valuable information. They may also have the architect's name providing a place to start." Extremely valuable info- noted.

"1) your electrical requirements in dwelling areas require more than you find in a typical garage. Additional items, if you have them) such as heavy electonics, entertainment, refrigeration (bar area?), etc can further drive the electrical needed.
Luckily, it's fully outfitted with electrical

2) windows. There isn’t much glazing needed in a garage. There are requirements in a dwelling area, and a lot of people want to exceed the minimums for bright spaces. So, you will probably be restructuring the existing back wall, in addition to the front. (I’m assuming the 3 bays to be converted are nearest to the existing living area.)

we would include in the plan new windows on the new walls we'd be building to replace the garage doors

3) What is your existing floor height in the living area ? How far is it above the garage floor ? Do you intend to have the new area match it ?
You may need intermediate support walls poured if you are matching floor height. (to keep your joist sizes down with width of the addition, assuming the current slab is left in place)"
Garage is 3 steps down from living area floor level. We would probably be putting in new floor joists or at least a vapor barrier, but not raising the floor much.


"Construction items to think about:
- In terms of foundation, nothing different should be needed. However, depending if you add floor joists or for some reason the slab is inadequate, they may require a thickened slab at the new separating wall.
- Your garage slab should be at least 6" lower than the house floor. The floor still needs that 6" height difference at the new interior wall door access.
not a problem b/c the door already exists up a few stairs.
- The exterior wall infill and interior walls will be sitting level with the existing garage slab and closer to the grade (no stem wall). Address water/bug issues.
- The garage slab slopes either to the door or a drain. Frame a level floor.
- The driveway slab/asphalt goes right to the wall. Remove at least some for landscaping.
- The layout should address a higher ceiling if it has one, the attic access, the exterior man door, and electrical panel if out there. Usually the garage man door is at the back of a kitchen or laundry room. This is not the best solution for access to a family room or bedroom. Consider renovation of the house. Also, large rooms require lots of light + ventilation (big windows), which your garage did not.
- The existing HVAC (mini-split or hung unit gas/infrared heat, maybe radiant floor) should be separate from the house, and is probably inadequate for multiple occupiable rooms. Would you keep it separate by removing it from the remaining 2 stalls, or connect new rooms to the house HVAC?
- The existing electrical probably can't be reused (adding load to existing circuits, high receptacles, general lighting, tool subpanels/disconnects) beyond adding for new layout, so assume a gut job.

"

I appreciate everyone's input. We will move forward with this in a couple of years. We also noticed that there is a gap- a hole in the driveway where it meets the exterior poured concrete wall by the garage. It measures about 5 inches wide by 2 inches deep. With a flashlight, I can see that under the exterior wall going back about 3 inches, and deep- maybe a foot even, there is a large gap. From looking at diagrams of walls such as these, it looks to me as if there should be gravel fill of some kind there. Does this sound normal?
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Old 05-25-2020, 04:50 AM   #10
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Re: 5 Car Garage Conversion


'normal' as in there probably was no hole before some animal needed a place to stay,,,throw some fill in there & pack/compact w/2x4 & hammer
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