Just met with some folks tonight that want to get a detatched garage built next to their house. They’re talking about a foot print of possibly 30 x 30… 900 square feet on the bottom, and it would have an upstairs area that would be finished at a later date for a guest room.
I’ll be looking for someone to do the do a slab foundation, so what $$$ should I be expecting as a ball park for someone to do the excavating (ground is pretty much flat already) set the foundation and pour the slab? They’re located about an hour south of raleigh nc.
Also, any recomendations for shopping for building plans for such a project, and what’s involved if we want to make any changes to a plan they purchace?
Replies
Plans should be such that the garage compliments the house.
You need plans before you can know foundation price. Also what types soils and frost depth. Somebody to decide if this is monolithic slab on grade or footer foundation with slab over.
And that size means either engineered lumber for the long span, or at least one post for beam in the center.
That post needs a footing located as part of the foundation.
And will this attach to the house or when you say right next to it, do you mean a few.....feet away?
All of this must be adressed by plans that consider the site, soils, and style before you can think about pricing. Otherwise, you can estimate one way and end up with plans that double the cost.
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It is almost pointless to reply because prices and conditions very tremendously.
I just bid a garage 26x30. Excavation and concrete came in at just under 5 k. This was for a floating slab on grade.
Edited 4/15/2008 7:24 am ET by Marson
I spent about the same last fall for one 24x24 with minimal dirt work
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".......with minimal dirt work"
Some of that (in)famous Maine ledge? :) .........no earthmoving required- just pin, form and pour.
Not on this one, it was on the highest point of the lot and had been used for a parking space for years so it already had good base. Had to level it off adding about 6-8" along the back side and compact it in
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I don't mean to be unhelpful, but have you done this sort of contracting before? Getting plans and producing estimates are pretty fundamental skills to doing this type of work. I don't mean you shouldn't do it, but be aware that being a successful GC involves a number of more complex tasks.
I understand what your saying. This would be my biggest project yet if I do it. done plenty of remodels, but this would be my first building from ground up. as long as it doesn't go over $30g, (which I think is right about where they want to spend) I'm allright legaly with no GC licence in nc... I have taken the course a few years back. Would I try to build a 1800 square foot house for someone right now... no. A small unfinished garage... certainly.
They're looking for a garage on a budget... slab, interior walls without sheet rock nor insulation, and an over head area to possibly finish out to a guest room one day. There would be power run to it and plumbing / sewage connections roughed in upstairs. They know someone who will come and do the siding. My part would be the slab (subs), framming, doors and windows, stairs (if there is a 2nd floor), sheathing, electrical (subs), plumbing (subs), shingles (subs) Right now they are just trying to get an aproximate idea of the overall cost, so they can decide on what size to build. the 2nd floor area may or may not fall in their budget. If I can get them a ball park for say a 30 x30, they can decide if they want to go a little bigger, or smaller, then pick out the plans they like and we'll do a real estimate off those.
I figured the price of the slab was some good information to start with as I try to come up with the "ball park" number in the next few days.
The soil... I'll see if they still have any geotechnical info from when their house was built, or the additions that were built in the past few years. it's between raleigh and fayettville, so it's probably just beginning to get a little on the sandy side. I'll try to talk to some of the local builders and cement guys about that area.
Didn't mean to doubt you. You sound like you have a good idea what you are doing. It was just that without all the details you provide in your second post there were too many assumptions to tell what the scope of work was. Did the excavation include perimeter drains, trenches for services, what type of soils etc.
With a bit of thought, the second floor can be quite cheap to rough in. Living-over- garage buildings generally end up being a nice scale project and are a good use of space. I don't know what your costs are down there. Our labor is still so expensive you would be hard pressed to come under $30g. If you are doing most of the work yourself that may help, but make sure you don't end up subsidizing it out of your own wages. Good luck.
They're looking for a garage on a budget ... over head area to possibly finish out to a guest room one day
Which are two different things, really, and the second one is the most expensive one of all. That's because you have to have all of the mechanicals into the 'garage' even if not needed. You also need some way to "trunk" all of those mechanicals "upstairs." Which then brings us to the thorniest of issues in the scheme, where to put the stairs that are not yet needed.
See, the stairs have to be where the roof above the room above permits, which is not always the best place on the floor where cars are going to be parked.
Then, there's the issue of this not being a simple slab, but a potential future dwelling unit foundation. Which is complicated by the long span diaphragm walls a garage typically has. So, stacking a half, or a full, story on top of the garage wall is a bit like building on stilts--the shear walls can really complicate the structural design, let alone the aesthetic one (by needing a wall right where a window or door ought to go).
Not that it can't be done, but that doing it "on the cheap" is really, really, hard. There are some very nice 'garagelow' plans out there, that might suit. But, note that you have to build the garage as if you are finishing the upstairs, roughing in a lot of expensive utilities, which might not be so pretty while this is 'only' a garage.
But, I'm probably biased, I may have seen too many ad hoc "garage apartment" deathtraps lurking about as rentals in my day (and not just 24' wide winder stairs, but built-of-2x4-winders . . . )Occupational hazard of my occupation not being around (sorry Bubba)
think anyone is listening?
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think anyone is listening?
Not to me <g>
Not even when the "customer" was unwilling to believe that the leak in the drain stack from the apartment above was because the wood wall sill set in the dirt was rotting away, not a defect in the plumber's work . . . <sigh>Occupational hazard of my occupation not being around (sorry Bubba)
They want a price so they can come up with a size, but the size dictates the price. you and they cannot assume a sq ft price and then adjust size accordingly! It takes the same time to cut and set a 22' rafter as it does to set a 14' rafter for instance.And the engineering and lumber size requirements are drastically greater for a 30 x 30 than for a 24 x 40 for approx the same size. BTW, 30x30 is a a good size for making an apt upstairs later, but a terrible size and waste of space for a garage. Style also makes a great diff in cost. I built a garage three years ago for 55K
Same size garage this winter for 25KThe difference was that one was totally utilitarian whole the other was carefully designed to the site and was meant to be a decoration for the estate as well.The whole process of asking for estimates based on an imaginary building is a waste of your time and everybody elses with no plans available.
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For a monolithic slab in our area it is $5.25 a sq ft give or take $.25 for turnkey or if you want to save some money you could hire a labor only concrete guy and buy the materials yourself.
If you are talking a stemwall slab that is a bit more complicated since possibly 3 subs would be involved. Or, to simplify things a bit I guess you could do a mono slab with a brick ledge. Then it would be pretty close to the above mono slab costs plus materials and labor for the brick.
All of the above is assuming good soil and that the ground really is pretty flat - say no more than 8 or 10" of fall.
Edited 4/16/2008 7:38 am ET by Matt
My sub would dig, form, pour and finish that as a mono slab for about $4,200. That would include the steel for the footing - 16"W x 12"D, a 6"W x 6"H stemwall on 3 sides and l&r of the door and the 4" garage floor sloped within that perimeter to the door apron. Take them about 1/2 day for the front end, wait for the inspection and pour and finish the next day. Vibrascreed and a power trowel, six guys on the crew.
I don't have frost problems or rocks and your milage may vary with the amount of extra prep required beforehand, ie., fill and compaction.