Any rough ideas for building costs?

We are very loosely kicking around the idea of adding onto the back of our house. Maybe about 400 square feet total, up and downstairs. Probably just put it on a slab, or crawl space. Thinking of expanding the master bedroom and adding a bathroom upstairs, and opening up the kitchen and laundry room downstairs. Nothing fancy, builders grade so to speak. Also have the potential of doing some of the work ourselves. Anyone have any ideas what building cost per square foot would be like in SE MI?

thanks!

I am also interestesd to see if there is an answer to this.  Building costs seem to be next to impossible to estimate without major effort or comittment.  At least, I have had difficulty findinag any answers.  

I don't think there is any way to accurately estimate it within a reasonable margin of error without someone out there looking at it and figuring out what you want. Too many variables.

Right now, good contractors have too much on their plates. If you want this to happen anytime soon, you're going to have to pay handsomely to make it worth their while. $150/sqft wouldn't surprise me at all though.

Edit: It turns out that $150/sqft is the current national average for new home construction

Obviously, if you want anything more regionally specific, you're going to need to get actual estimates from actual contractors.

For small additions it is very difficult to estimate per square foot, because the area count is so low.  The bigger the project, ironically, the easier it is to ballpark estimate.  And accurate building cost estimation is a major effort.

At 20' x 10', on 2 stories, assuming structural modifications to open the walls up where you are attaching to the existing house, roofing and siding and foundation tie-ins, I would WAG it at somewhere between $30,000-$40,000.  In most places, trades are busy right now.  You may be able to get it cheaper; probably not.  Most builders that are capable of getting it done in a reasonable time frame also need it to be worth their while.

You'll have a concrete guy, maybe also a mason, a carpenter, a roofer, a plumber / HVAC guy, an electrician, drywallers, painters.  Some of those trades may be combined, or some you may handle.

[edit]  $150 / sq ft is about right for new home construction.  That will be to a decent quality grade and includes extensive HVAC and plumbing, which I'm omitting from my number above.

Completely impossible to guess. 

You haven’t really even defined the square footage (is it 200 SF upstairs plus 200 SF downstairs, or 400 each, totaling 800?)

Remodel work is generally much more expensive than new construction.  Smaller projects cost more per square foot.

https://www.costtobuild.net/

http://legacy.building-cost.net/CornersType.asp

BUT, some people WILL guess.

Most of them will be contractors whose business model is to try to land jobs by telling you what you want to hear (low price).  These builders make their money through change orders. 

If you don’t give them good information up front (like a complete set of plans), then they won’t give YOU good information up front (like an accurate price). 

SVreX said:

Completely impossible to guess. 

You haven’t really even defined the square footage (is it 200 SF upstairs plus 200 SF downstairs, or 400 each, totaling 800?)

Remodel work is generally much more expensive than new construction.  Smaller projects cost more per square foot.

Sorry, I guess I worded that funny, 400 square foot total, up and downstairs combined I should have said. 

I was just trying to get a rough idea, is it a 20k dollar project or 60?  20k would still keep us under the value of our house, 60 is way above. From what it sounds like, at 100$ per square it would be 40k. Probably not worth it in the end. But, then again, a lot of the work can be done ourselves. My brother and I built our garage, everything except the foundation... but we are not carpenters and I don’t honk I’d look forward to doing it again. 

In reply to joey48442 :

It’s not $20K. Not with a new bath, kitchen modifications, and HVAC changes. 

Tangent: For those who "know", how hard is it to move a staircase? I'll draw a picture later to show what I'm talking about, but our house was built in 1927 and modified... kind of strangely throughout the years and I'd like to completely re-route our upstairs design which would involve adding a "box" to the back upstairs as well as moving the staircase entirely. 

SVreX said:

In reply to joey48442 :

It’s not $20K. Not with a new bath, kitchen modifications, and HVAC changes. 

Of course, I didn’t expect it to be, it was just a “for example” price. Just trying to guess what I’d be looking at. And if it is high, well, my dads a plumber and I have an old friend who’s a master electrician, and they work for dinner and bicycle parts, so that would help if it’s too expensive. As for the furnace, this is all directly above the existing furnace so that will help. And when we bought the furnace the size of our house was right in between the recommended furnace sizes, so we went with the bigger option. So I shouldn’t have to move up in furnace size. 

In reply to joey48442 :

Sounds like you have a good sense of the variables (which all cost money), and the ways in which you can save. 

Square footage pricing for construction really amazes me. It’s a system completely designed to take advantage of the consumer. 

We wouldn’t find it acceptable in almost any other business. “How much does it cost per wheel to build a custom car?”  

SVreX said:

Square footage pricing for construction really amazes me. It’s a system completely designed to take advantage of the consumer. 

We wouldn’t find it acceptable in almost any other business. “How much does it cost per wheel to build a custom car?”  

My dad got so hung up on that when looking for a house for my little brother. It was shocking to me, especially since they were looking at tear-downs. How much is the lot worth? That was the only question that mattered in that situation.

SVreX said:

Square footage pricing for construction really amazes me. It’s a system completely designed to take advantage of the consumer. 

We wouldn’t find it acceptable in almost any other business. “How much does it cost per wheel to build a custom car?”  

I get your point, but slightly disagree... only because it’s the main thing for a house after of course you make sure it’s safe and sound, whether or not it’s big enough for your needs. It’s more like how many dollars per horsepower will this mod cost?  Like a thousand dollar exhaust that adds 10 hp, or a 4,000 dollar turbo that adds 100 hp. 

It may not be the best way to judge value, but I’m certain if I came on here asking about “how much does an addition cost?” You guys would have asked right away “how big of an addition?”

thanks for your advice, SV, I almost added “paging SVreX to the front desk” to my thread title

SVreX said:

In reply to joey48442 :

It’s not $20K. Not with a new bath, kitchen modifications, and HVAC changes. 

I somehow missed that he was adding a new bathroom.  Yeah, you'll be at the upper end of my range.

In reply to joey48442 :

I’m not trying to derail your thread. You asked a fair question. 

But square footage pricing does not benefit consumers. It benefits lazy tax assessors, and lenders. 

Keep in mind- all construction is custom. 

So, your horsepower comparison doesn’t really work. If you were looking to buy a locost or a race car someone else built, you would not look at wheels or horsepower first. The first thing you’d look at is quality.  You’d post pictures here, and all of us would argue about weld penetration and roll cage design.  You would expect to pay more for a car built by Flyin Miata then one built by me. 

In square footage evaluation, all square footage is treated equal, whether it is by a E36 M3ty entry level builder, or a premium custom builder. It’s only about size, and location. 

This system serves tax assessors well ( who want to take your money, and don’t even know how to measure a house square footage), but it doesn’t serve consumers well who would like a good product that can serve them well for decades. 

Size is not most people’s primary concern. That’s why HGTV highlights features and upgrades.

Rant off. 

In reply to SVreX :

No derailment worry. I think size isn’t the most important thing to people who don’t live in essentially a 450 square foot living area. My house is 900 but the upstairs is all kneewall I can’t stand up in. I need to talk to a contractor who I can bounce ideas off of, see if it’s all viable even. Can you fit a half bathroom and bedroom in 200 square feet?  I’m skeptical. How much of my wall needs to remain to support the roof?  Then I can go to the builder and have them quote me   

joey48442 said:

SVreX said:

Completely impossible to guess. 

You haven’t really even defined the square footage (is it 200 SF upstairs plus 200 SF downstairs, or 400 each, totaling 800?)

Remodel work is generally much more expensive than new construction.  Smaller projects cost more per square foot.

Sorry, I guess I worded that funny, 400 square foot total, up and downstairs combined I should have said. 

I was just trying to get a rough idea, is it a 20k dollar project or 60?  20k would still keep us under the value of our house, 60 is way above. From what it sounds like, at 100$ per square it would be 40k. Probably not worth it in the end. But, then again, a lot of the work can be done ourselves. My brother and I built our garage, everything except the foundation... but we are not carpenters and I don’t honk I’d look forward to doing it again. 

Adding sq ft to your house and updating it at the same time should increase its value.  Please note the should.  If you are already overbuilt for the neighborhood or the neighborhood is going down it won’t.   

You’re kinda caught in the chicken and egg question.  Which comes first the addition or the value?  Now it depends on how you intend to pay for this.  If you already have money available then do what you want.

If on the other hand you need a home improvement loan you have to get bids from contractors to present to the bank ( along with plans drawings etc).  

There is a third way  but you likely won’t do that. 

I really understand what you’re trying to do.  Put a rough number on a proposed addition  to see if it’s the best way to go      Or!  Sell and buy a bigger place?  

As someone has pointed out it’s not going to be the national per square foot for new construction. Not with bathroom and kitchen remodel. 

If you want to use a quick and dirty number that could be wildly off try $200 a sq ft  plus the cost of the things you want in the kitchen and bathroom.  

Mind you saving your old appliances/ cabinets etc can exceed the cost of new.   Depending.... 

mtn said:

Tangent: For those who "know", how hard is it to move a staircase? I'll draw a picture later to show what I'm talking about, but our house was built in 1927 and modified... kind of strangely throughout the years and I'd like to completely re-route our upstairs design which would involve adding a "box" to the back upstairs as well as moving the staircase entirely. 

You don’t really move a staircase. You build the new one and tear down the old.  Only rarely would it be possible to “move” a staircase.  

The other thing is older staircases likely do not meet new building codes. 

frenchyd said:

mtn said:

Tangent: For those who "know", how hard is it to move a staircase? I'll draw a picture later to show what I'm talking about, but our house was built in 1927 and modified... kind of strangely throughout the years and I'd like to completely re-route our upstairs design which would involve adding a "box" to the back upstairs as well as moving the staircase entirely. 

You don’t really move a staircase. You build the new one and tear down the old.  Only rarely would it be possible to “move” a staircase.  

The other thing is older staircases likely do not meet new building codes. 

... that’s what I meant. Never occurred to me to physically move it. 

In reply to mtn :

The answer to your question is, “It depends”. 

It can get tricky, especially in an old house. 

It’s not “hard” to me, but I’ve spent a lot of years building stairs in old houses. Be glad to help if you need it. 

In reply to frenchyd :

Fortunately we already have the smallest home in the neighborhood, values are going up, seems most stuff is selling between 110 and 130 or so within a few block area, and we owe less than 80. If I added 400square feet I’d be right about 1300, very typical in this hood, same with the 1.5 bath. 

Just for a real world example:  Complete bathroom remodel now under way in Frederick, MD.  Complete tear out down to the studs and start over.  Not much plumbing involved as no fixtures are going to be relocated, but all new fixtures.  Tile floor and tub surround(ceramic tile, not marble), Granite top single sink vanity, new lights, mirror, etc. 

Cost on contract (no change orders yet) :  $21,725.00   We picked out all the materials, fixtures, etc. before the contract was written so I expect the price to be fairly accurate.  Once we had picked everything out and I had made some drawings we had 3 different contractors bid the project.  They were all within a $300 price range.