We're considering expanding our facility and this will partly include a new spray booth.

I believe we will have the option of building a larger add-on and locating the spray booth inside that building, or buying an external standalone spray booth and just butt it up to the building with a large pass-thru door.

We are looking to increase our capacity to spray upwards of 100-150 cabinet doors per day. I think we could achieve this if our actual spraying area were approx. 20x30ft. All the prepwork and final curing would happen in the main building.

From a manufacturing/maintenance perspective, are there any advantages/disadvantages to buying one of these as a standalone, joined up to the building...... vs...... building a larger building and putting the spray booth inside (with filtered entry doors on it)?

Are you planning a make up air unit or just filters in door?
Guess it depends on if you need heat?
What part of country are you in?
I would build a new building and include a curing area in there

First person to talk to is your insurance agent, second is fire marshall, then consider weather control. Most booths are just thin sheet metal, never seen one stuck on the side of a building. Pump warm make-up air into a chilled sheet metal building and you will have condensation dripping everywhere. Same happens when chilled air pumped into a hot tin shed. Build another building that's fully insulated.

I would second everything Rich said, insurance and building/fire codes in your area will determine what you can and can’t do.

Gents, thanks for the tips, and I definitely agree with Rich.

We're in a humid environment so condensation would be an issue for sure.

We're in a pretty hot climate most of the year but winter needs some heat mostly for curing the paint, our lows are usually 40's, sometimes upper 20's but not often.

We aren't likely invest in a make-up air solution just for heating although that's not decided. Natural gas around here isn't terribly costly & even in this chilly winter, it doesn't usually run the whole day.

A professional spray booth and a make up air unit go hand in hand. I can’t comment on the building and fire codes in your area, but I would be surprised if you could put a spray booth in with out a MAU.
Your booth will be exhausting 5000 cfm plus, how do you replace that air?
You can leave your windows or doors open, but it won’t be long and your building will be a similar temp to the outside.
You shut your doors and windows and then you put your building into a negative pressure so the air comes through your exhaust vents for your furnaces/heaters and you fill your building with Carbon Monoxide.
A professionally installed spray booth will have the exhaust and supply cfm closely matched so your booth will always be set at 70 degrees or what ever temp you prefer. It will make the task of spraying so much simpler and easy.