what is the average cost of adding a 12x12 room onto a house?

Asked by cam10nv, Napa, CA Wed Jun 13, 2012

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Ron Thomas’ answer
Ron Thomas, Agent, Fresno, CA
Wed Jun 13, 2012
Do you think that there are a lot of people out there, adding a 12 x 12 room; so that we could obtain an AVERAGE?

And is this a slab or raised ground-floor addition?
Is it a second story addition?
Is construction in Napa a wee bit higher than Stockton?

I am sure that it has so many variables that your answers will be: Please contact a contractor for estimates.

Do you think?
0 votes
Well Mr. Perfect, it seems that many people were able to answer the question and they did it without being rude. Also, what was the value proposition of your statement, you didn't add a single bit of value other than revealing your true character. You may be wondering what my value proposition is - go back and read your profile, you should learn how to proof read a formal bio before posting.
Flag Tue Aug 11, 2015
Wow! What a complete jerk and very unprofessional. Maybe someday someone will pop you right in the mouth one of these days because that seems to be what you deserve. I hope one day when you have a question outside of your scope of knowledge that you're treated in the same unnecessary, uneducated, narrow minded fashion...jerk.
Flag Tue Apr 14, 2015
You are rude and out of line. It is only a question. I would not consider doing business with you under any circumstances.

This is my home, not my dog house.
Flag Sat Feb 28, 2015
Now retired - but I was an agent in California for 25 years. What's with the "Do yo think?" The client is asking for advice and this agent could have steered him in the right direction, as Mr. Andersen did.
Flag Sun Jun 24, 2012
John Arendsen, Agent, Leucadia, CA
Wed Jun 13, 2012
Ron offers up some pretty sound advice. There are indeed a lot of variables to your question. Before I'd contact even a contractor and waste a lot of their time I'd first do down to the building and planning department and find out what their requirements are.

Then I'd contact an architect or an architectural draftsman at the very least as a 12x12 would hardly capture the interest and/or attention of a full blown architect. You will have to have a plan before you start wasting a contractors time unless the contractor could design it for you which they often can on very small projects.

Once you have a plan a contractor can then proceed to price it out. If you are talking a one-story level without any plumbing or kitchen features, say a bedroom or any study and it was a slab on grade vs a raised floor you'd probably be in or around 100 to 150 per sf. If, however, it was a bathroom you'd probably be looking at around 200 per sf or a kitchen addition you'd probably be looking at about 250/sf,

You can add on about 25 per sf for 2nd story additions and 50 per sf for a raised floor with a concrete perimeter wall. All that stated that would be San Diego price points.
1 vote
this is the answer I was looking for. I am adding a 11 x 10 to the back of house that way the bedroom will be 20 x 10, slab
Flag Mon May 30, 2016
Adam, , San Francisco, CA
Fri Jul 6, 2012
Contact Napa Architect Sarah Marshall. She's an expert with these types of additions / renovations.
0 votes
Darrell D. D…, Agent, Schertz, TX
Wed Jun 13, 2012
The answer to this question is as much of a guess as "what's the average price to purchase a car?".

Please consult a licensed contractor with your specific specifications for them to determine the requirements to meet your specs based on current building design, electrical capacity, plumbing updates, etc.
0 votes
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