I am curious as to what is typically done with taking a commercial building, something like a mill or factory, and converting it to a condition for selling residential ‘loft’ space. More specifically, when companies convert a building like this for residential use are they typically required to pre-install the plumbing, or is it left up to the loft buyer to determine the loft’s internal layout and thence install plumbing raceways?
Has anyone here ever participated in the renovation and conversion of a commercial space into a residential space? I am really curious about the mechanicals (HVAC, electrical, plumbing, etc.) and the toughness of the skeletal structure of the building. I remember reading how some of the targeted for demolition buildings in Detroit were a PITA to take down because of the original construction strength.
Most commercial buildings like factories had pretty high ceilings, but the idea of ‘raising the floor’ for the sake of plumbing seems silly, and the notion of cutting into the concrete floor to run plumbing seems foreboding. 🙂
Replies
Ponytl just posted about this subject- I think you can find that thread in the photo gallery section. Very nice work, and a good melding of commercial, residential, and his own way of doing things.
zak
The turnover point from developer to buyer depends on the project- some are taken to fully complete, while some are left as empty shells. As you mentioned, plumbing is a royal PITA when it's done after the fact, especially when the unit below yours is already occupied. In some cases, the waste lines are roughed in and capped, with finished fixtures by the buyer- but the locations are pre-set.
The "toughness" of the skeleton depends on the building type- I've seen very strong wood-framed buildings and very flimsy concrete framed buildings. Typically though, wood is the lightest, with steel being stronger, and a concrete frame being the stiffest of them all. With a wood or steel frame, you generally have more to do to acheive the required fire ratings for residential use as well.
Bob
Hey Bob, I was concerned with the requirements (if any) and difficult) in cutting into high-pressure concrete slabs in order to stub-in plumbing. I wasn't so much concerned with upper floors of a given building unless they are also concrete. Somehow, I doubt the strength of the concrete in some of those heavy mill floors were made as wimpy as those in tract homes of today--but Murphy always likes to prove me wrong. :)
In most of the older buildings, it's not the strength of the concrete (that's easily fixed by a diamond coring rig), it's the amount of rebar that slows you down (but still gets cut through by that diamond core). Back in the day, the theory was "if 4 bars is good, 10 must be better".
Bob
I'm involved in a loft finishout now. It was originally a candy factory for a few yeaqrs in the 40's, then became a commercial office space (one owner-tenant).
First, the concrete strength ... it's only 6 floors high, but as you go up, the strength goes down. The top floor is only about 2,000 psi.
The developer added a plumbing stack in two places through all the floors. This includes a copper water supply and two CI drains, plus a gas pipe (for cooking only, must be electric heat). All other plumbing is the responsibility of the tenant-owner. Holes are cored in the floor and the lateral lines are in the ceiling of the space below.
Each space is responsible for it's own hvac, using Trane residential-style units. The compressor unit is on the roof of the second floor, and the a-coil & fan unit are in the ceiling of the respective space.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
First, the concrete strength ... it's only 6 floors high, but as you go up, the strength goes down. The top floor is only about 2,000 psi.
That's pretty typical on taller buildings, but not usually worth the hassle of coordinating different mixes on something as low as a 6-story- that's surprising. The 50-story tower I'm currently estimating has shear walls that start out at 10,000 PSI at the lower floors and reduce all the way to 6,000 PSI at the top. There's about 20,000 CY in the shear walls, so the cost savings in switching mixes 5 times as you go up is substantial.
The developer added a plumbing stack in two places through all the floors. This includes a copper water supply and two CI drains, plus a gas pipe (for cooking only, must be electric heat). All other plumbing is the responsibility of the tenant-owner. Holes are cored in the floor and the lateral lines are in the ceiling of the space below.
How are they handling it when the 5th floor unit sells, and the new owner has to try and run plumbing in the ceiling of the 4th floor below, which is already occupied?
Each space is responsible for it's own hvac, using Trane residential-style units. The compressor unit is on the roof of the second floor, and the a-coil & fan unit are in the ceiling of the respective space.
That sounds like a real PITA system to service later- especially when the refrigerant lines for the 6th floor unit springs a leak in the wall of the 3rd floor unit it passes thru. I pity the people whi have windows near the 2nd floor roof with all of those compressors running in the Texas summer heat.
Bob
Got me interested here... what's the recipe on a 10K PSI mix?
Got me interested here... what's the recipe on a 10K PSI mix?
High cement content, low water/cement ratio, silica fume added to the mix, and a high-range water reducer (superplasticizer). It's not cheap stuff- mostly because of the silica fume and other additives- 6,000 PSI concrete is running around $75/CY here currently, while 10,000 is around $130. But where the strength is needed, you don't really have a choice.
Just another benefit of working on the big projects that I do- access to expensive and out of the ordinary materials and applications.
Bob
Edited 3/17/2006 8:05 pm ET by BobKovacs
Ha ha... you think that's expensive, the ordinary 3000 PSI mud I get is $140/yard. Add a few things to it and it's $160. Of course, you're buying in quantity and I'm not.
Of course, you're buying in quantity and I'm not.
I'm also buying from companies that typically have a plant within 10 miles of wherever the project is, while you're buying from the one guy on an island who has to barge all of his raw materials in, has two trucks, and can charge whatever he damnwell. Sucks living in Mayberry RFD, doesn't it??? lol
Bob
"Sucks living in Mayberry RFD, doesn't it??? lol"
You mean compared to Joisey??
Seriously, how many sacks of cement in a yard of 10000 PSI, and what's the slump it's batched for?
There's approximately 900 lbs of cement in the mix, so that's around a 10-sack mix. With the super-P, you can get it to a 5-6" slump easily- more if you want it. Usually we'll look for around a 6" slump to get it through the pump and to minimize the vibrating that's required to get it into the forms and through the piles of reinforcing that are in the shear walls and columns that the 10k mix is usually required for.
Bob
Wow, a ten sack mix.... and probably that 1-1/8" square rebar too. You're making us little residential guys look like punks. You could drive on that stuff an hour after pouring it.
I've never used any "square" rebar, but there's plenty of big bars. Number 9's like you're talking about are for sissies- most of the pile caps and columns in the high-rises lately have 12's and 14's with barely enough space to slip your hand between them.
Bob
I assume all of your stuff is factory-welded into cages and shipped to the job to be moved by crane. Handling it any other way would really take the fun out of it. Every carp I know would quit before lunch and head for the unemployment office if you made them move a piece of #12 bar.
I assume all of your stuff is factory-welded into cages and shipped to the job to be moved by crane.
Nope- most of the time the cages are fabbed on site and then craned into position. They aren't welded, though- they're tied. Typically, floor, wall, and beam steel is all tied in place- column cages are pre-tied. The only time the steel usually comes to the site pre-tied in for caissons- that allows the caisson sub to avoid having ironworkers on site (they use lower-priced non-union guys to tie the cages offsite). They pick the cages right off the trailers and drop them into the shafts with the crane.
Every carp I know would quit before lunch and head for the unemployment office if you made them move a piece of #12 bar.
That's why we don't use carpenters for reinforcing work- we use ironworkers. The carpenters build the forms, and the ironworkers tie the bar.
Bob
I'm surprised about the site fab. I would have thought the work was done off site to speed things up. I bought pre-bent rebar from a supplier in the Bay Area a few times, and every time I went there the factory was filled with big cages being put together... welded, I thought, but maybe not.
Mostly just kidding about the carpenters and I do know the diff between ironworkers (they call themselves 'rod busters' at least on the west coast) and carps. I think there are two Bay Area ironworker locals (or more), one that handles rebar and one that handles structural steel erection.
Anyway, residential carpenters groan when they have to bend some #5 for footings. I can do a couple of hours of that with bar benders and then I'm toast.
I'm curious about how high you can build with site-precasted concrete tilt-up panels. Even if you tilt up the ground-level panels that might be 20' tall and lift-up a second course, how do you brace, tie-in, and or interlock the courses? Any written good books on this kind of construction for the purpose-built construction topic at hand?
Why not just make the column out of steel?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Why not just make the column out of steel?
Kinda tough to do that in a concrete-framed building. We have embedded steel beams in foundation tie-beams on occasion, when the beam size has to be kept below a certain size and there's no way to get enough rebar into the beam. But typically, it'd be too difficult to get the composite action that's required between the steel and the concrete, and to tie the steel column into the floor reinforcing.
Bob
Depends on the building and how the units will divy up.
There was one in Dallas where your con-dominion rights ended 1/32" away from the existing finished of your unit. Yep, you could not do anything to the brick walls dividing, or to the exterior & its windows, or to the exposed roof/ceiling structure. Only thing you could touch was the floor. So, all the mechanicals went in by floor. Not so bad, really, though, the floor was broom-finished concrete with about 4 decades of fork & pallet-jack wheel scuffs on it.
I want to say the old Sears & Roebuck, they "preplanned" all the condo layouts. But, I can't remember if they built, ot you got to build the units out. I do know that one of the first commercial lease space to condo conversion downtown is still gone horribly wrong--they treated it like "traditional" TI lease space, big mistake. People boring through the floor for plumbing--oops, whaddya mean, you downstairs people ain't got no ceiling; wha' sorta pre-verts gots no ceiling . . . ?
paul simon said it bestIt's just apartment house rules
So all you 'partment fools
Remember: one man's ceiling is another man's floor!
This is what I do... for myself but also as a consultant for others wishing to do the same...
Vents are the worst... bathroom and dryer vents... most even in the $300sf range which is on the high end here, have laundry rooms vs WD in each unit... Yes it's cheaper for most to build new... infact now the trend for many are "loft projects" which look old but are 100% new...
in my current project only 3 story 4 if you count the rooftop deck & gathering room..... I removed 50% of the concrete 1st floor for plumbing... ran a ton of extra pipe just in case... this is the first one that i've ever done/seen that didn't have a a full basement ( this was one of those buildings you see in old pictures where they hauled goods up from river barges on cogged wooden gangways... housed civil war troops ect...) but with a basement it makes life a bit easier... most become underground parking,
hvac... what i use and push on others is package units on top floors, split units on bottom & lower floors,
unfinished space... I don't see alot of that anymore... too much $$ to be made selling a finished unit... there are always upgrades and alot depends when (how early in the project you buy)
depends alot where you are... but there are tax credits for buildings over 40years old and more if it's historic or in an historic area... there are pilot programs, and some low interest seed money for some... enterprise zones also hold some advantages... but most of these things are for the builder/developer.. which is another reason it's not dollar wise to sell unfinished space...
In some areas you can do a project and if you as the owner hold it for 5years (not fix & sell) you can sell it between the years 5 & 9 and have no capital gains tax on your profit... which is why you see many projects done as rentals and later (5yrs later) become condos...
on the project I'm doing now i have 100k in nothing but engineering & plans... this is to be able to build it exactly how i was going to build it anyway... I see alot of screwed up work and budgets blown on these deals mostly because so much has to be designed on site... if you think plans are screwed on new construction... rehab'n old commerical buildings where there is no way a vent/drain...ect... is going to pass through a 20" concrete beam.... or designers not seeing or knowing which way joists run... run'n pipe through 4x16 oak joists 12"oc takes alot of pipe, fittings & drilling...
i have onsite... a diamond bladed chainsaw, 3 walk behind floor concrete saws... 2 handheld diamondblade demo saws... 2 corebit rigs... and at least 15 diamond core bits..., and thats the short list....
p
"unfinished space... I don't see a lot of that anymore"
That's the way it is out here, in the Bay Area. I work for a drywall/ metal stud company and the "loft" conversions we do are all turn key, really just condo's.
It is neat working in a lot of the old warehouses (etc..), though.
I remember some artist friend's lofts back in the day, now there was some interesting living quarters. Mike
Trust in God, but row away from the rocks.
You bring up and interesting point I chatted about with the guy I carpool with. You said, "infact now the trend for many are "loft projects" which look old but are 100% new" and this reminded me of the This Old House 1836 Barn Project in which the structure was too bad to 'restore' so they built a new timber structure and mimiced the original barn.
Using precast concrete and steel framing, I wonder exactly how reason (compared to renovating existing structures) a loft project can get.
it's all in the "feel" I sold a guy a 40ft x 24" riveted I-beam really a goodlooking old I-beam looked like it came off a bridge or something it was gifted to me and i never had to move it but the guy used it exposed in a new "suburban loft" it gave him a 40ft clear span and a heck of an industrial look
think about it... large open spaces... concrete floors... industrial materials... I think the cost per SF could be way down there before you add the 100k kitchens and 30k baths but those would be in any upscale house anyway... anything that wasn't a perfect fit & finish is "character"...
p
Edited 3/17/2006 12:49 am ET by ponytl