Cost to add top floor addition on brownstone
Can anyone give rough cost to add a top floor addition to a small (3-story) brownstone, which is NOT on a landmarked block. I know there are lots of variables, but if you’re just trying to add something that is say 450-550 sf (say a master bedroom with bath), is there a ballpark? 100K? More?…
Can anyone give rough cost to add a top floor addition to a small (3-story) brownstone, which is NOT on a landmarked block. I know there are lots of variables, but if you’re just trying to add something that is say 450-550 sf (say a master bedroom with bath), is there a ballpark? 100K? More? How big a deal is it to break through and then have to add a new roof/skylights?
I have done this several times. The first step is to determine what your foundation will support and the condition of your walls. You may be able to use a lightweight construction method. If you have to do foundation work it will be quite expensive. Without the foundation work $250 a foot is in the ballpark. It is mostly straightforward work on the roof.
I’ve added to a Brownstone. “They” will give you price for everything that’s needed for the addition, but that price will not include all the things they’ll find will need to be done once they start. They may have told you to set aside 10% as a contingency. It could also be 50-100%. I’m sure I haven’t had the best experience you can have, but I wouldn’t do it unless money was not a limitation. Old buildings are like old people, even minor surgery can lead to devastating complications.
Hi,
The first poster is right. The structural work required is quite costly. I wanted to add a large roof deck and ran into a similar problem. The engineer wanted to reinforce the entire roof. I know that it doesn’t seem to make sense but the code in NY is very strict. I wanted to build a two car garage and due to code and Landmark’s requirements the price was $500k. It would have required a very deep foundation. I passed.
4:51 – I’m OP. Just curious what kind of bldg do you have now? Sounds like it’s a big brownstone – 20 x 50? And then you’d rent it out? We have a smaller brownstone (16.58 wide by 40 long, 3 floors) so are just thinking of how to add another bedroom for a master suite – and are not sure whether it’s better to do it on the roof or by building extension on garden level – do you happen to know which is more expensive? Thanks!
You have to have the foundation inspected by an engineer to determine the strengh but most attached brownstones should be able to bear the weight. I am doing a similar project and have had prices of from $150 to $240 per/sq/ft. The higher bids are from more experienced, some union, contractors who promise, among other things a faster finish. We’ll see. I just got a price today on the chimney extensions for myself and my abutting neighbor, $200 per foot, approx 3 chimeys x 20ft for about $12,000 by itself. We are building our 1000 sq. ft. project with steel and stucco, the only masonry will be the chimneys.
I’m planning on dropping more than $240,000 only because I have other building stuff I am going to do at the same time. But at $240 per sq ft to build, 700 per square foot of value and $34/per/sq/ft/per/year rental value, How don’t you build? You pay the thing off in eight years with the rent.
I have friends that tried to do this – but didn’t in the end, because they learned that the 4 story townhouse’s foundations wouldn’t support it in their existing conditions. She spent about $10,000 on an architect, structural engineer, goetechnical (soil) engineer, and environmental engineer to come up with a plan to strengthen the building. She then tried to get estimates from 6 contractors, and only got back estimates from 2 (I guess the others didn’t want the work), and found that it would cost a MINIMUM of $70k IN THE BASEMENT before work could begin upstairs. Yikes!!! Of course, calling off the project is much better than striding ahead and accidentally knocking the building down… Be very careful to have structural and geotechnical engineers look at the project, don’t just wing it!!!
For an additional floor, most people will say plan for $250/ square foot. That is a ballpark price.
I am considering a similar project, but we have a pitched roof, so we don’t have to actually go higher than the present peak.
Do you have a flat roof?
Masonry must be added on both party walls, plus the flues if any must also be extended in masonry or at least multiple wall stainless.
There is demo on the existing, plus new floor and roof joists. If your street has to be blocked for the crane that is another expense for permits.
I would guess that you will run through all the first 100k, but then still have to do interior finishes. So depending on your taste for fancy fixtures, I would go to 125-130.