I would actually do a separate structure, and call it a 'carriage house.' I know I'm the odd one out, but I would love to be able to go outside the main house and have my own quiet, private space (with no danger of, knock, knock, "honey... can I ask you a favor?" lol). I don't think I would do a shed, it seems like getting water and electricity out to it would be a huge pain, and I'd rather just have my little carriage house. If you are worried about resale, it could be dubbed a guest house, mother in law suite, artist studio, etc. I would even go as far as to cover the walkway to get there, and it would absolutely have to have a wood burning fireplace. :D

You've given me a lot to think about. Our garage is not attached to the house - it sits off to one side and behind the house, so its not possible to connect the two.

I've thought about a dumb waiter, stair chairs, etc., but the way the garage was constructed, there just isn't room to put anything like that in. BTW - the stairs are inside the garage.

We have a very small house and the only room I could consider taking over would be the dining room. But that would be a fraction of the size of the room I am currently using and it wouldn't fit my long arm (or much of my sewing stuff period).

I'm thinking the addition might be the way to go, because I plan on spending another 20 or more years in that house. The fact that it would add value to the home is something to consider as well.

Wow, I have just fell in love with this idea. Wouldn't it just be awesome to have a carriage house as a quilting spot!

I would go for an addition. Reasons: bathroom, nearer kitchen for coffee and snacks, no having to go outside. Also, I think a nice addition would be a good investment for your home value. I have a second floor studio and sometimes it gets a bit lonely.

Well, if you build one, I reserve the right to come and visit! I have a very active imagination for a grownup, and pictured myself quilting away in a little carriage house in the woods. Fire going, snow falling, husky romping outside. Sigh...

Too many questions to give a simple answer. What are the building and lot line restrictions where you live? Building costs between shed and addition may be equal, but I'm sure running electricity (maybe water for a potty?) to a shed will cost more. Your weather conditions require they be buried 4' deep. Extending your home's electric in an addition will not cost nearly as much in installation or the price of copper wire. You can step into an existing bathroom easily from an addition. With an addition you won't have to go outside at all in bad weather.

Now, how old is your home? Does it meet current building code? Sometimes when remodeling (adding on to) a home it is necessary to completely rewire or replumb the home because the existing does not meet current codes and you can't just add on to what's there. This would definitely apply in a home older than about 40-60 years that has not been updated already. A lot to consider.

The cheapest option: Have hub install a dumb waiter from the garage to the studio so you can empty your hands before you climb those stairs.

How far apart are the garage and house? If they are adjacent, could you add an addition that joins the two buildings?

At my Dad's house, I have an outside shop that has lots and lots of electrical plugs and many advantages. The least of them being a heating and cooling problem. It is something to consider if you are going to build a she shed. With an addition, you would only have to extend the existing components.

I think adding on to the garage and a proper staircase would be cheaper and if you can attach with something like a breezeway would be a good solution. My friend stores her stash in the "attic" of the garage. Her DH put in a pulley system for her. It has a staircase but not much head room. She can attach a basket or hangers and take them up or down. So no carrying anything.

I would think the addition might add more to the value, especially if were done with resale in mind.