600 sq-ft garage build

[AlpineSeven]

Hello all! I’ve been a lurker on this wonderful site for a while now and what better time to emerge from the shadows then with a garage build. I purchased a house recently with a dilapidated single car garage. The original plan was to expand the cinder block garage but for various reasons I have canned that idea. After months of research I’ve settled on a stick built two car garage with a metal roof. My local zoning, Charleston SC, allows 600 sq-ft on an accessory building. I’ll post a screenshot of the other zoning codes below.

My requirements for the space will be:

Fit 2 cars
Separate metalworking and woodworking workbenches
Tall enough for car lift
Exhaust fan for a paint booth
Electrical that can handle an air compressor, welder, and woodworking tools
Comfortable winter and summer
Small attic for storage
Sink and or part cleaner

At 600 sq-ft I’ll need to be mindful of what I put in there. Especially with the variety of projects I find myself in. I’ll be taking a large amount of inspiration from Jack Olsen’s 12 gauge garage.

I scoured the internet for a 600 sq-ft plan that would fit my requirements. I settled on a 36’ x 24’ layout that I will scale down to 30’ x 20’. I went ahead and purchased these plans and have been learning Chief Architect to make my own custom plans. More on this later.
https://www.behmdesign.com/product/designer-garages/816-7/

And here is my site plan. Excuse the potato quality, I made this on my work computer and I’m at home right now.

It’s a tight neighborhood layout and my neighbors master bedroom is 6’ behind my fence. To combat the late night noise I’ll be making I’ve settled on rockwool insulation. Preferably I’ll install the rockwool on the exterior between the siding and sheathing. This adds complication and takes up square footage though. Don’t blame me if I take the easy route and insulate between the studs.

Matt Risinger on exterior insulation:

For the lift I’m going with a dual scissor lift to save floor space. And the bonus of two adjustable height work tables!! The height of the ceiling will be an issue with the 11’ eave height in my towns building codes. Haven't decided if I’ll do scissor trusses yet to get more space. Any advice here would be greatly appreciated. Speaking of trusses, the Behm Design plans I purchased call out for attic trusses with a low 5’ attic height. I’m not a fan of this. I’d prefer to go without trusses if possible and increase my ceiling beam size to compensate. Any thoughts here?

For the lift I’m going with the Atlas FM9SL. It’s a popular option in the scissor lift thread on this site.


Alright, this post is heading towards War and Peace length so I’ll wrap up with my current standings in the design. I’ve got the size right, but will need to decide soon if I’m doing that floorpan cutout shown in the Behm design. My biggest hurdle right now is the truss design.

And here are most of the codes in my local city regarding accessory buildings:

 

[captain14]

No pictures are showing except the ad and diagram of the garage. Sometimes an extra “s” needs to be removed.

Are you planning on building it yourself or contract it out? Is the old garage demolished yet?

 

[matt_i]

Not sure. Scaling the pictured design down to 30x20 is going to lock out a fair number of full-sized vehicles with the 20' depth.

I don't think you're going to get much of a vehicle service lift with an 8'1" wall height. Have to modify with scissor trusses and/or a higher wall, etc.

I also think its pretty constraining to shrink the 12'x20' shop down to 6'x16'-ish. Its better than no shop but the car parking area is going to be jammed to the point I don't think any toolboxes, etc can be placed over there. Just thin stuff on the walls.

 

[Tracs]

OK. A few things. I respect your determination to build the garage you want. But I think it was a waste of $240 on blueprints that will need extensively modified, but not the end of the world.

11' eave height. That means you have a 11' ceiling with the trusses spec'd out. Depending on what you want to do with a lift that is enough height. More than enough to lift a car with space to park a car under it. If you don't want the attic......which I extremely suggest you should....because with the decrease in floor square footage the storage will be immensely invaluable. But if you don't want the attic and if you use scissor trusses that will give you enough room to lift anything.

And finally, at 20' deep, which once framed will turn into 19'... you won't be able to park anything larger than a car.. which is fine if that is all you ever plan on putting in there.

PS. After typing this out I realized that with the garage doors in the place they are, a jackshaft opener will be required and even with that you won't be able to open the door with a vehicle on the lift.

 

[Tracs]

I fixed your pictures.

 

[cvairwerks]

I’d suggest that you make up 4 stands and use some caution tape and lay this out on the driveway for a reality check. At 20’ exterior dimension, you are looking at about an 18’ interior dimension when completed. If you want to be able to walk around either end of a parked car and the door closed, it will limit you to something less than 16’ in length.

For data points.. a 2019 Toyota Camry is just over 16' long and a 2019 Honda Civic is just under 16'

 

[AlpineSeven]

Thanks for all the help!! It was the HTTPS that caused the pictures to no load. Should be fixed now.

To answer a few questions I am going to build the garage myself, although I'll higher out for the foundation and trusses. I purchased the Behm plans to help with the attic design. And I needed an example to follow for my own plans.

I see a lot of concern for the 20' depth and I am a bit concerned myself. Here is a sample layout I created a while back. Since creating this layout I've added french doors to the right side in an attempt to expand my work space onto a patio.

My two current cars are a '06 3 series and '72 240z. Both small cars which is what I prefer. It would be nice to fit a mid sized truck on the lift if I pick one up in the future.

The afternoon I'll to work out a few different layouts that keep in the small 600 sq-ft.

I do want to keep the attic for the storage. As Tracs mentioned the added storage space will be needed in this small of a space. How do you all feel about half attic trusses and half scissor trusses. Giving me the height to lift a car and some storage.

The zoning office did mention I could appeal to the board for a larger garage. I might stop by with the plans I picked up as a feeler for this option. I know there are larger garages in the neighborhood. Not sure if they are grandfathered in or appeals.

 

[AlpineSeven]

Played around with a bunch of layouts. Eventually most ended up looking like either of these two layouts. I'm more keen on the 21 x 30 layout that keeps the work space. BTW those cars like blobs are the size of my 240z and 3 series. I'm still going to stop by the city with my purchased plans and hope for approval on the 24 x 36 layout.

 

[andyvh1959]

A good looking garage, some nice details. But, why have it stand some distance from the existing garage, when the code limits you to one out building, meaning the existing garage will be demolished? Your site plan proposes an extended driveway to the new garage. Could you build this garage over the existing garage position and actually increase the square footage? Also, that would get your shop garage further away from your neighbors house and you'll gain more usable yard. And you'd save money on putting in less driveway.

Some city codes allow larger square footage IF you attach/maintain the original out building. Now, that leaves some room for interpretation as to how much of the original out building remains. As an example, up here in Wisconsin some lake properties allow a new construction onto an existing old structure to utilize the setbacks of the past, but also to allow some square footage gains. In some cases new buildings are built onto the old structure by only using one wall of the old building. Point being an adaptation of the city code may be possible if you build onto the existing garage and only retain one wall of the existing structure. Would an "attached" design allow you to build bigger square footage? In your case, an attached garage from the rear porch to the new garage? Attached does not mean the house and garage actually would have to share any walls, as I found out years ago on my previous property garage build.

I previously lived in a small country town of 3,000. I had bought the materials and had the CAD drawing for a 1320 sq ft detached garage. The materials I bought was a 26x40 garage I got cheap, broke down to sections and moved to my site, trusses and all. Went to get my permit to find out I was limited to 900 sq ft for a detached garage even within the setbacks my site plan was already meeting. The city clerk said an attached garage had no square footage limit (yeah, I know, odd). So I designed an attached covered walkway from the house to the garage, in essence making it an attached garage, but still on its own locked edge slab. Got my variance on the city code approved and I built my larger garage. The covered walkway actually turned into a really functional design, I could walk from the garage to the house in pouring rain and not get wet.

On your site plan, if an attached walkway from the rear porch to the new garage would allow for greater square footage, you may be able to build the garage deeper for a bigger footprint. Would also require less driveway, put the money into the garage and not the driveway. Then, you could have a pass through garage, with an OH door on the rear, so a vehicle could potentially be parked behind the new garage.