garage extension or stand alone

[65_valiant]

I need more room, not an uncommon phrase amongst my fellow garage dwellers im sure. I currently have a 20x20 attached garage and was thinking of adding on to the back of it a 20x30 extension. Ideally I would like to go wider than 20, but then I wouldn't be able to drive my vehicle into the backyard area where back my trailer into when I store it. Has anybody done anything like this? Any pros cons to think of? I will be upgrading my electric service at the time of build.

My house is the one on the bottom in this picture. The existing shed behind the garage it will be moved if I decide to do the extension vs. the standalone.

 

[65_valiant]

Here

 

[BobRae]

Additions are more expensive than stand alones, but I'd prefer the addition because you end up with one large space instead of 2 smaller ones. Best thing is to compare quotes for the two options.

 

[bczygan]

Additions are usually less expensive than stand alone.

Most places allow only one accessory building, so the shed would have to go for a detached.

You need to decide what functions it will have and whether they would be better done close to the house or further away.

What area? What weather?

What are setbacks and easements?

Attached may allow higher structure.

Access for construction can be a factor.

Detached uses up more yard with setbacks.

Detached has to have utilities run further.

Detached provides better separation of noise and dust and fumes.

If you add a wider structure, an extra garage door on the back will allow you to push a trailer all the way through and into the back yard.

If I was using the existing garage for automotive functions which were mostly maintenance and parking, and the additional functions were more intense shop functions and included woodworking and machining and welding, I would be tempted to do a detached shop in the back corner of the yard.

If I just wanted to park more cars and add some car related functions, I would add on the the back of the existing garage.

What functions do you want to add?

 

[CNGsaves]

This is little "out of box" idea, but consider adding a drive-thru garage door at back of your existing attached garage (see yellow line in drawing). This would let you drive-thru to back yard detached oversized garage. Concrete would connect the space between both garages. See detached garage in back yard that would be added (ie red in drawing).

The small garden supply shed would be saved but moved to other corner (ie see blue in drawing).

Finally, if your easement would allow it, add a lean-to carport on the upper edge of house in picture (ie left side) so you'd have easy place to park trailer or another car without having to drive-thru garage to new detached. Effectively, this would give you 5 under-roof parking spots (2 in attached, 1 under carport, & 2 in detached). This carport area would still be drive-thru to back yard so you'd have 2 ways to get vehicles to back yard.

If easement won't allow the lean-to carport, then just leave that open so you'll have 2nd way to get vehicles to back yard. A carport roof in front of new detached garage would give you 2 more spaces under roof which could get you up to 6 overall.

 

[kbs2244]

An addition will require a below the frost line foundation in most jurisdictions.
So, a slab foundation stand alone would be cheaper.
Plus you get a buffer zone that keeps the dirt, noise and smell of a shop out of the house.