Tweety, Other/Just Looking in Berkeley, CA

addition costs per square foot

Asked by Tweety, Berkeley, CA Wed Jun 15, 2011

What are the average square foot costs foe an addition in California? Specifically in the San Francisco Bay area? we're thinking of doing either a one or two story addition to our home but need a place to start
Thanks

Help the community by answering this question:

Answers

16
Tim Page’s answer
Appraisers and banks never rely on average cost per square foot. Here is what you do. Hire an appraiser to appraise your home “as is” or as it stands now. If you have a refinance appraisal within the last three months, this may work too.

Now get another appraisal as if all of the additions and improvements have been completed. Compare the values before you begin construction.

It might cost you $600 to $800 to do this, but this will be priceless.

This will tell you if you should add more square footage and how much money you may lose and you can compare that with selling your home and buying a newer home with more square footage.

Most of the time, the cost of the remodel and improvements do not even come close to paying for themselves in my market area.

Secondly, when it comes time to appraise the home, you may have created a non-conforming home and depending on the area, this may increase or decrease your home value. One may pull the value up, while the other may pull the value down.

In your area, this might be the best thing to do or this might add significant value, but don’t guess on this one. It’s too expensive.
0 votes Thank Flag Link Wed Jun 27, 2012
Needless to say, construction costs in the Bay Area are steep. For a ballpark figure, on a one story addition of about 200 sqft with basic finishes that you'd find in those of national home builders, you should budget around $300/sqft. The price goes up to $500/sqft as you dip below 100 sqft and down to about $250/sqft as you go bigger. Add a second story and you can usually average down about $50/sqft. If you want to add another bathroom in the addition, that's another $10-15K.

Of course, from here you'll have to get multiple bids from licensed general contractors to get a real figure. You can check on angieslist.com or yelp.com Bids for similar work can vary widely so compare closely.
Web Reference: http://www.archershomes.com
1 vote Thank Flag Link Wed Nov 30, 2011
The cost per square foot to build such a relatively small living space is higher than most people expect it to be. I explain why on my article on Cost of Home Additions. I also show you how you can use free cost estimating software to obtain a rough estimate for your own addition.
Carl Heldmann
1 vote Thank Flag Link Mon Nov 28, 2011
I have to chime in with the others. As a general contractor, developer 25 years and an RE broker I must say that's a pretty open ended question. $100/sf if you're doing a bare bones "Accessory Dwelling Unit" (ADU) which can be as basic as a factory built structure.

Start talking foundations and you're at least doubling the price so now you're looking at $200/sf. Add custom upgrades i.e. granite, wood flooring, high end doors and windows, upgraded appliances and the sky's the limit. I've seen homes in Rancho Santa Fe, La Jolla, Del Mar, Encinitas, etc fall in at over $2000/sf.

What you need to do is sit down and write up a wish list starting with square footage. Do you want to expand your existing footprint? Build up? Add a free standing structure? Convert a garage if permitted? Then figure out what type of upgrades you want.

Once you've got a basic wish list you should then reach out to an architect for the structural and an interior designer to help you layout your plans. But be prepared to pay for these professional services. These folks are pros and don't work for free.
1 vote Thank Flag Link Thu Jun 16, 2011
Additions depends on what you're doing -- a simple room won't be quite as expensive as adding an entirely new bathroom that requires plumbing, etc.

Here's a link to Remodeling Online's Cost Vs Value 2011 in the San Francisco area. This should give you some approximations of costs

http://www.remodeling.hw.net/2010/costvsvalue/division/pacif…

Hope this helps!
1 vote Thank Flag Link Wed Jun 15, 2011
Hello Tweety- Your question can't be answered very easily as it depends on a lot of different factors. Are you going to have new foundation or retrofit the existing foundation . Is it a sloped lot or you are adding to a flat lot. How many SF you are adding, how many more baths and or kitchen? To give you a wide range, you can do it from $100/SF to $500.00/Sf. I have built and remodeled homes many times during last 30 years in SF Bay Area.
One of my first additions for just 300SF cost me about $250/SF, 20 years ago.

If you like to chat about your goals , I will be happy to share my experience with you.
Best of Luck, Kirk Ansari,415-819-7777- You may want to see my profile on my website
1 vote Thank Flag Link Wed Jun 15, 2011
Whats the most important part of you're home ? The structural integrity, Hire a framing contractor to build you're home.. They specialize in that, structurual engineering/framing. The most important part. Hiring a general contractor is not always the way to go, Jack of all trades ? No thanks ! We tried that... Example if someone was to work on my diesel truck i would much rather hire someone who specializes in that.. Makes sense to me !!!
0 votes Thank Flag Link Fri Jul 11, 2014
He probably already got his answer, as this question is three years old.
0 votes Thank Flag Link Fri May 23, 2014
$200 per square foot will cover the additional space as well as the sysmic retrofit that is typically required. If you want to strip the entire shell off and open the space to modernize, plan for $250 a square foot.
Jack Thompson
415-298-4788
General building contractor
#757692
0 votes Thank Flag Link Fri May 23, 2014
The average price for an addition really depends on what kind of finishes you are looking for.
You are probably going to be in the neighborhood of 250.00 SQ. FT.
Standard grade finishes.
If you have any more questions feel free to give me a call
Al with Al's Remodeling
415-724-1087 http://www.alsremodelingsf.com
0 votes Thank Flag Link Tue Jun 11, 2013
I highly recommend Berkeley Parents Network as a resource for recommendations from homeowners who have hired contractors for their own homes. Contractors all have different strengths, and preferences, like every profession, BPN allows you to pose specific requests for info, and you will get a wealth of answers, in addtion to their pages with past recommendations on almost any topic you can think of.

Good luck!
0 votes Thank Flag Link Wed Apr 4, 2012
I highly recommend Berkeley Parents Network as a resource for recommendations from homeowners who have hired contractors for their own homes. Contractors all have different strengths, and preferences, like every profession, BPN allows you to pose specific requests for info, and you will get a wealth of answers, in addtion to their pages with past recommendations on almost any topic you can think of.

Good luck!
0 votes Thank Flag Link Wed Apr 4, 2012
Hello Tweety,

You can search for service on website like Service Magic and get a quote from local contractor or may be a couple estimation from different licensed contractors. Next you need to see the works done by those experts before you can make any decision. Don't forget to check with the city planning department for new building code and what requirements needed for new addition and the cost of pulling a permit. You need all the numbers for your budget. Good luck
0 votes Thank Flag Link Thu Dec 1, 2011
I would start with a search for a reputable remodeling contractor. Most good contractors will come out for an initial feasibility assessment and provide a “ball park” estimate based on the amenities you want to include.

Cost per square foot can vary significantly depending on what type on addition you are doing. Where a family room – bed room addition may run $150-200 per/ft an average kitchen – bath addition may be $600-800 per/ft. There is great disparity in costs regionally, and economy of scale (smaller sq. ft. cost more to produce)

In most cases a 2 story addition is more cost effective because the foot print is half as big (less dig-out, foundation, and roof)
0 votes Thank Flag Link Thu Dec 1, 2011
This will cost you much more than you think as stated below. I have several contractors in the area that can help you design and budget such a project. They would be the best one's to speak to as they know current and local codes and cost.
Web Reference: http://www.markkotch.com
0 votes Thank Flag Link Thu Dec 1, 2011
All real estate answers start with 'it depends.' If you figure about $400 per square foot, that could get you in the ball park. Price depends on whether you need to re-do the foundation, how much modification you need to do to the first floor for seismic improvements, whether or not you are in a natural hazard zone, whether or not you are doing plumbing, how new or old your original house is for architectural details, adding heating, etc.
0 votes Thank Flag Link Wed Jun 15, 2011
Search Advice
Ask our community a question
Email me when…

Learn more

Copyright © 2015 Trulia, Inc. All rights reserved.   |  
Have a question? Visit our Help Center to find the answer