A few more images I just remembered I had...

I'd leave it open if you don't mind cooling that extra volume. Does builder plan to frame roof similar to what you have? I would think they would us trusses at 24" on center, which will make overhead space less useable. Also hip roof will give you less space above.

You need to design around the lift, not sure what you will have as the first sketch shows a 4-post but you have 6" concrete for a 2-post? Is that the 2-post or a trench drain shown in the equipment sketch? The elevations show an 8'-0" high OH door (as well as man door and window head height??) with a top plate of 9'-0"?

I assume the jogged footprint and wall height is to get within SF and height regulations? Can you do a gable? With the hip, you can't gain the inside height with scissor trusses. Also you can high-lift the OH door up the gable to not interfere with the lift.

Is that the attic ladder shown between cars?

closing the ceiling off will allow better insulation, therefore more efficient heating and cooling. IDK about you, but if I had a detached workshop like this, I would only heat it "on demand" so I'd want the best insulation possible.

also, rafters can get super dusty and cobwebby. if you want to keep that storage, could you convert that area into a small attic?

The photos of current shop are a common rafter w/ gabled ends. I know know exactly how the trusses etc will be but I'm fairly certain they'll be less storage friendly than what I currently have. Point taken but it is what it is.

I am going from 8 ft to 10 ft walls however affording me the option to build some deep/tall HD shelves down 1 or 2 sides (and if open ceiling - would have easier access to suspending supports for shelves from overhead perhaps.

I currently have the silver aluminum clad sheets above and it helps with lighting. The foam would look 'splotchy' to anyone looking up - but I believe it will be a white-ish color (unless it turns yellow w/ light exposure?) yielding a simlar effect for light.

I don't really care about heat even though the future split mini may offer it. I do care about cooling (Texas) and for cooling - I don't really see a downside for the open ceiling in that regard. On my current shop, when I go 'upstairs' to get something down - it's a LOT warmer up there due to heat rise. The garage doors will only rarely be open - during summer months, AC will be running pretty much all the time.

I don't like the flourescent tube lights on current shop - they were cheap (years ago) but uncovered I always worry about breaking one while not paying attention. Little limited in mount options w/ only joists. But I'm sure something can be figured out for shop lighting to open rafters...

I may just have the builder put the cheapest bare bones switched light fixture up there and I'll put something much nicer up at a later point.

The open rafters afford a HUGE opportunity to store big things up there like bike frames and 4x8 sheets and long pipes or strips of wood... But now that I think about it - going from 8 to 10 ft makes it a little trickier to put stuff up there all other things being equal... hmmm...

And I have to decide on if (and where) to put a pull down ladder or just use a step ladder. Dimensions suggest joists will run front/rear so a ladder could line up and fit between the car bays. But that's the same place I like to put pull down drop lights and power and probably lights. Sigh... it's never easy!

open ceiling spaces can get hot. I've lived in a couple of homes like this and not having an insulated attic makes a difference in the summer. if you get some decent venting and a roof that reflects the sun that will make a difference though! it also helps to have a tree or something nearby that can shade the building.

Do you mind sharing how much this is expected to cost? my husband wants a woodworking shop in our new house we are designing. we did it as a partial basement and the cost is astronomical but he is onky a novice wood worker for fun and dont think its worth 75k. debating asking our architect to redesign with a third car garage or something instead or doing a separate shop later

Is this going to be a garage with a shop (the two cars make me think that is what you're planning) or are they they there just as a size reference?

You won’t have enough height with standard 10’ ceilings. A lift requires a minimum 13’ vaulted area for a low sports car to occupy when on the lift, and have standing working room under it. Higher is better if you own a SUV or truck. 16’ is ideal. It also requires more space in between the vehicles for service carts or tool boxes.

A 2 post lift is a giant PIA for most jobs, and requires point load footings for attachment. A 4 post is more stable, doesn’t require attachment to the slab, and generally is better for 95% of service work.

Build a single floor shop that contains all the storage you need on that level, with a flat ceiling. If you put in a second level, use it to tie flies.

Do you know about garagejournal.com?

@Verbo, I don't know about the original poster, but almost all of the work I do on my cars involves removing wheels (replacing shocks, brakes, hubs. bearings, etc.), which is why I'm considering a 2 post for my garage. Can that be easily done on a 4 post?

Yes, with a bridge jack.