alas, the metal building on the property I bought 7 years ago leaked then. we have caulked all the screws and seams twice over on the roof. the windows leaked, and lots of framing rot and mold now in the old building. I am afraid it was past time to replace it. we tore it down between install and takedowns this year. it was a 30x88, It had 9 foot sidewalls with stick framing, and a 3:12 pitch truss roof that gave me a 13 or so foot peak in the very middle. as far as how much was warehouse space, had an office and 2 bathrooms in the middle 350 square feet or so. ( used to be a church). as far as rack cubic footage, which really underlines what you can store in a building, it had 11,500 cubic feet to put wreaths and boxes in . still hard to believe I ate all that space quickly, and in 2010 started the new building ( then ) 35 foot wide 88 foot long building right beside it with 20ish foot sidewalls and a 4:12 pitch roof for an eventual 26 foot peak. or added 64,000 cubic feet of usable space! That build thread is on here somewhere. if someone knows how, feel free to find it and link it in a post, I don't know how to do that. I thought both would be plenty until I ran out of employee parking space, but ah, the details. when you go taller, you need a lift to get stuff up and down. and to get lots of boxes and wreaths down daily, you need a pretty decent sized lift. which leads to decent width aisles. and wide aisles get you no storage. and all those bay doors on the new building mean you can't store stuff in front of them. so while we built a beautiful 2 sided middle pallet rack all the way to the ceiling, and built some pallet racks above the bay doors and on the end, our storage for the inventory and customer stuff ended up being about 20,000 cubic feet. we could've bumped that another 10,000, but the guys already gripe about moving the lift around now. moving the lift around is a huge issue to go from aisle to aisle. you have to leave room at the ends to swing it, and you can't have the aisle too narrow or the guys run the lift into the pallet racks. the truth is, ideally you have 4 foot deep racks against the 1st wall, then an 8 foot aisle, then 9 foot double sided rack in middle, then 8 foot aisle, then another 4 foot racks over the loading doors and between them. and maybe a big opening in the middle of the middle rack to get the lift through it. I think we will get another lift just for the new side and to have a spare, especially since the new side will be tall now too. we had really reached the point of if we had to put everything in one building and be able to tear down the old building and build new, it had to be this year. If we waited another year, then we would've had to rent warehouse space somewhere else, move it over there, then build, then move it back. as to the new add on, I probably will regret this, but I am just going to start at the 20 foot side height of the new building a few years back, do a fairly flat 1:12 pitch over the existing 30x80 slab and end up with a 17.5 foot sidewall or so. will still have 350 square feet of office/bathroom space, but no weird hallway between office and bathrooms, and just one bathroom, so a much better office space. but will have storage above the office bathroom space too . so, doing the math, an average of 18.75 usable height, times 2050=38,437 plus 350x8ft tall=2800 cu ft, so a total of 41,237, or another 20,000 cubic feet of new air space. I considered and ran the numbers for a 35' sidewall and going to the peak of the newish building I built a few years back. but the engineering on a wind load on a sidewall that tall is brutal. would've had to do all steel posts on that side and some pretty chunky steel beams/trusses to get to the other peak. other factors, like finding pallet racks that tall, although they exist, it would be fairly ugly, and my builders uncomfortableness with that idea nixed it. and I will look back on this statement and regret it, but right now doubling my previous cubic footage to replace a leaky building seems fine, NOW. I will try to post costs and take and post pics as the progress goes.