Cost to add on to an existing house.

I’m interested in a fixer upper residential house that is 797 sq ft. The lot is 9,500 sq ft. For 797 sq ft and what the list price is, there is no room for profit. However if the house can be expanded another 1,000 sq ft, the potential profit could be 6 figures.

My question is in general, what is a ball park figure of how much it costs to expand a house 1,000 sq ft out (toward backyard)? Or 500 sq ft out and 500 sq ft up?

I’m just looking for a ballpark figure to have an idea if this could work.

Thanks for any input.

I was quoted (and this depends on your area) but here in south florida My insurance lady told me the price per square foot for new construction is hovering around $75/sqft so at that rate your looking at $75,000. :frowning:

Campbellgroup - Thanks so much for the reply. I was looking for a rough estimate, and you provided that for me. I guess now I’ll call a few local contractors to get some estimates. I really appreciate your help.

I added 840 sq feet (with 2 1/2 car gar below) to my 864 sq foot house in Wisconsin in 1999.

I did everything myself except for excavating and concrete work, HVAC, plumbing, gutters, and laying the carpet.

Also, I went pretty fancy - solid wood doors, finished wood trim, awesome master bath with jacuzzi ect ect.

Cost $55,000.


Are you afraid to out price yourself in the neighborhood? That is always one of my concerns. what are your #'s like?


Olie, You do need to be careful not to make your house way too much more than the others in the neighborhood. When future buyers are looking they could possibly overlook your property and even an appraisal could be a bit lower just because of the other comps in the neighborhood and other “like” homes.

Olie - I’m not concerned about pricing myself out of the market because I live in California which is already ridicously overpriced.

The 797 sq ft. house list price is $459K in a neighborhood where larger houses sell for $600K-$900K easy.

I’m still not sure if this will work because I’ve been quoted a local price for construction (add ons) of about $150-$200 per sq ft. That price alone will totally destroy my budget.

But thank you all for your comments.

If you are interested I am a mortgage broker and work with other investors who I finance on the purchase of a home with a construction loan and end loan built in. This has been a great option for many of the investors I work with. If you want to discuss this further please contact me.