home addition ballpark prices? (rental, appliances, house)

[karen_in_nh_2012]

Yeah, I know, it varies a lot ... just curious about ballpark figures per square foot?

I'm thinking of making a current "junk"/TV room into my kitchen (it's much bigger than my current kitchen, which I HATE) and adding a room off the kitchen in what is now my back yard ... the back yard is huge and beautiful and I'd love to have a breakfast/exercise/TV room overlooking it.

It would likely be anywhere from 12x16 to 16x30 (I'm dreaming!! ) and wouldn't need much in terms of extras -- i.e., some electrical outlets but no plumbing or anything like that. Probably 3-4 very basic windows (or 2 larger ones). I don't know if it could be done on a slab or if a crawl space would have to be constructed (the "junk" room is part of an addition from the late '70s and it has a crawlspace that's connected to the main house's basement).

I'm in western New Hampshire, which is likely a BIT cheaper than eastern New Hampshire, but who knows.

So, has anyone had an addition put on their house, and if so, can you please share details including ballpark costs?

Thanks!

[buck naked]

Twenty years ago we built a 20 X 30 barn. It cost $10K for the foundation slab. The balance was another $15K in building material. 2 windows, 2 doors, no plumbing, electricity.

So if you build it yourself, I would estimate double that cost due to inflation - You are looking at $50K...ballpark.

[karen_in_nh_2012]

Thanks, Buck! 20x30 is about twice as large as I am LIKELY to go, though, and this would be partially attached to my house/garage (I assume your barn is detached).

I am curious as to why the foundation costs so much? A slab in particular is just poured concrete, right? (Clearly I know nothing about the price of building materials ...)

Anyone else?

[buck naked]

Originally Posted by karen_in_nh_2012

Thanks, Buck! 20x30 is about twice as large as I am LIKELY to go, though, and this would be partially attached to my house/garage (I assume your barn is detached).

I am curious as to why the foundation costs so much? A slab in particular is just poured concrete, right? (Clearly I know nothing about the price of building materials ...)

Anyone else?

barn is attached in an L - the garage is between the actual house and barn.


rebar, wire mesh, reinforcing steel, hangers...delivery - it all adds up. The average cost for a cubic FOOT is $100-!25.

Permits were expensive also.

[Brave Stranger]

I did a 12X14 all-season room on a slab in Mass in a rental property I own. I knocked down a wall in the back bedroom to link the addition. Simple space with a tile floor, celling fan, paint, cable, electric, 5 windows & a door with a raised celling. Cost me about 26k. Should run you about 20k in your area I'm guessing. The "BIG IF" is if you run into ledge when dig the space out. That may cost you 3k-5k more. Good luck

[unit731]

Foundation is crucial.
Full foundation?
Crawl foundation?
Piers?

[bignhfamily]

You would want to use a monolithic slab if it's attached to your house. A floating slab of this type can shift and cause movement between the 2 structures. You'll need footings below the frost line to prevent movement.

$150 to $200 per square foot is our average new construction build but a kitchen could be a lot more if your talking new cabinets, counters, appliances, etc

[karen_in_nh_2012]

Originally Posted by Brave Stranger

I did a 12X14 all-season room on a slab in Mass in a rental property I own. I knocked down a wall in the back bedroom to link the addition. Simple space with a tile floor, celling fan, paint, cable, electric, 5 windows & a door with a raised celling. Cost me about 26k. Should run you about 20k in your area I'm guessing. The "BIG IF" is if you run into ledge when dig the space out. That may cost you 3k-5k more. Good luck

I assume that was recent? Thanks for the info, it's very helpful. (Except I'm not sure what you mean by "run into ledge" ... my soil is apparently good for gardening -- i.e. not hard clay or anything.)

Originally Posted by unit731

Foundation is crucial.
Full foundation?
Crawl foundation?
Piers?

As I wrote in the OP, "I don't know if it could be done on a slab or if a crawl space would have to be constructed (the "junk" room is part of an addition from the late '70s and it has a crawlspace that's connected to the main house's basement)." My house was built in 1960 with a full basement (typical where I live); an addition was added in the late '70s -- that's the "junk" room plus an extra bay on the garage to make it a 3-car garage. The house part (i.e., the "junk" room) has a crawlspace that is attached to the original basement.

Originally Posted by bignhfamily

You would want to use a monolithic slab if it's attached to your house. A floating slab of this type can shift and cause movement between the 2 structures. You'll need footings below the frost line to prevent movement.

$150 to $200 per square foot is our average new construction build but a kitchen could be a lot more if your talking new cabinets, counters, appliances, etc

The kitchen is totally separate and I can price that myself based on a kitchen I did back in '09 at my old house. This is for a room OFF the kitchen that would be very basic as described in the OP.

I do have a couple of relatively inexpensive labor sources ... one is one of my tenants who helped a colleague of mine build his house. The colleague raves about him. The other is a different colleague who actually installed my kitchen back in '09 -- he's amazing. So I'm HOPING to keep the labor costs relatively low (would definitely have to hire someone to do the foundation, though -- I don't want to take any chances with that!!).

Thanks for the replies -- I'll rep everyone I can. And if anyone else wants to chime in, please do!

[Snafu]

I had a 24' x 28' 2-story gambrel garage built in 2011, and the foundation for that ran me about $6300, with an additional $5K for excavation (a lot of lot leveling and boulder removal - it IS the "Granite State", after all). The foundation itself was a 16” footing, 8” wide by 48” tall wall, and a 4” slab for the floor.

[Brave Stranger]

Originally Posted by karen_in_nh_2012

I assume that was recent? Thanks for the info, it's very helpful. (Except I'm not sure what you mean by "run into ledge" ... my soil is apparently good for gardening -- i.e. not hard clay or anything.)



As I wrote in the OP, "I don't know if it could be done on a slab or if a crawl space would have to be constructed (the "junk" room is part of an addition from the late '70s and it has a crawlspace that's connected to the main house's basement)." My house was built in 1960 with a full basement (typical where I live); an addition was added in the late '70s -- that's the "junk" room plus an extra bay on the garage to make it a 3-car garage. The house part (i.e., the "junk" room) has a crawlspace that is attached to the original basement.



The kitchen is totally separate and I can price that myself based on a kitchen I did back in '09 at my old house. This is for a room OFF the kitchen that would be very basic as described in the OP.

I do have a couple of relatively inexpensive labor sources ... one is one of my tenants who helped a colleague of mine build his house. The colleague raves about him. The other is a different colleague who actually installed my kitchen back in '09 -- he's amazing. So I'm HOPING to keep the labor costs relatively low (would definitely have to hire someone to do the foundation, though -- I don't want to take any chances with that!!).

Thanks for the replies -- I'll rep everyone I can. And if anyone else wants to chime in, please do!

I just finished up the project this spring. I also ran the heat out there which required a second zone added to the boiler. Ledge, or stones, could be under your land where you can't see it until they dig. If there's a lot of ledge they will have to blast which is very expensive.