I don't know anything about such things, but I'd guess if you take the market value of your house, that would be the bare minimum for the cost to add a second story. That assumes your foundation can support a second load. I'm afraid if you're worried about being shocked, you are going to be very shocked.

What is it about your house that makes a huge remodel more attractive than buying a different house?

Nashville is a very hot market. We were in a bidding war just to get our house and bid $20,000 over to get it. That was 2015 and it has gotten much more competitive. They tear down small houses and build million dollar homes. So we love our location and didn't get the space we needed but bought a the lower end of our house budget. I have been looking for a bigger place but it the prices are hundreds of thousands of dollars more for not much more sq. ft. and they still need complete renovations. We have a big yard and it is close to work, etc.

That's a good suggestion about market value. but it is rising so fast here...

• I understand loving your location and not wanting to move but it comes at a cost. I added 104 sq feet above an existing sunroom at the cost of $650 per sq ft. Granted you per sq ft cost in a larger addition will likely be less since people are on site already but it will not be less than new construction ever. Even in the least expensive COLAs , cost to build additions run over 250 per sqft.
• A few big item costs people do not seem to remember to add into the equation are redoing landscaping for the exterior will be effected greatly. Expect your driveway to age years by the wear and tear of trucks daily. Also expect to have to find alternative living arrangements on a job the size you are talking about. Work will need to be done to the existing areas too. Siding will not match often, walls and ceiling need altering, footings need to be strengthened.
• Good luck.
  

It was almost as costly as tearing down the house and building new on a project I was involved in, which is what the client ended up doing.

A friend was quoted approximately 400.000(second story over a slightly smaller ranch, but in Silicon Valley) and moving out for a year. Have no idea what her quote included. For example when we remodeled our contract didn't include finished materials, with some exceptions-so add materials to it, if her quote was more like mine.

They bought another house instead. A bigger one. Lots, lots of money. But if you add up the very approximate quote plus the very high rent they'd have to pay living somewhere else during the remodel plus everything unexpected plus huge inconvenience plus..

They'd probably pay the same, in her area. If not more. And they wouldn't have a time of their lives, I assume. I hadn't.

We gut remodeled plus added to the new house while living in the old one. It'd be smarter to just move and pay several hundred thousands more right away. Of course we didn't know exactly back then. Well now I know.

Putting finances and huge effort and time aside though-it did allow us to reach some of our goals for the family, that we might not reach otherwise.

In my area (NJ, 30 miles outside of NYC), it would cost around $300-350k in construction costs. Another $15k or so for plans/permits.

We added a 1200 square foot second story to a 3000 square foot ranch in Dallas. Allocated costs are around $125/square foot for the new portion, $50/square foot for the total gut/remodel downstairs. $300k all-in remodel cost. BUT we were very, very careful about budget (getting multiple bids, holding our GC accountable for every penny, and so on). Also, the foundation was already exactly the shape we wanted (u-shape). Of similar import, we had an almost perfect substrate--minimal foundation work was needed, we didn't need to move substantial numbers of walls, etc.

Ended up saving around $50/square foot versus a new build of similar size/finish-out.

And remember, there are economies of scale. Adding a 600 square foot second story to a 1500 square foot ranch gut (so exactly half the sizes) could easily be 80% of the cost of our total remodel.

In all, our numbers are probably closer on the spectrum to "best case" than median--not sure we could replicate it again. But that's the datapoint we have to share.

Loki, what kind of finishes did you choose? Were they higher end? We are not planning a gut remodel to the first story, maybe just to the kitchen and den. We may go in phases but do the biggest thing first being the addition of more space. I will use the most basic finishes to keep costs down. I have read differing views on if it is more expensive to add up than out, so real stories are very helpful. Thank you!

Hard to say how "high end" a finish is. We put in solid hardwood everywhere except the bathrooms and laundry room and quartzite counters in the kitchen and master bath. Those items were around 15% of our total remodel budget. Other bathrooms have marble or quartzite floors.

My strong conclusion is that up is cheaper than out if you don't need significant foundation work to support the second story. Otherwise, it's probably a wash.

Doing it in parts will almost certainly be more expensive than doing it at once. And you are unlikely to realize value from a low-end finish-out. There's just not enough margin to find good deals.

This is not a process for the faint of heart.

KF, Would you mind telling us what the cost ended up being? We are in the process of considering a similar project right now in the Nashville area. Thanks!

Loki

Hi - I saw your post on Houzz on adding a second story. I’m looking to do the same in Dallas. Would you mind passing along the name of your builder and architect/designer? is there a way to direct message on this site? Many thanks!