Pushing Out 4 feet

[jello]

I hope some of you wise folks can give me some advice. I'm doing what should be a fairly simple rennovation, but I've never delt with foundations before.

The back of my house has a U shape. I'm going to extend the middle part out four feet where it will be flush with the rest of the house (thankfully there won't be any roof line issues). I've done lots of framing before, but I've never tackled a foundation. I know I'll need to pour footers and tie them into the existing foundation, but since I've never done this, I'm looking for any help or sources of information on how to properly do all of this.

Can anyone offer any advice, or the title of a good book on the subject?

Thanks.

[VALENT]

Where are you? What type of foundation is used on the house?

[jello]

I'm in Los Angeles and it's a raised floor foundation with an 18" crawl space.

Thanks.

[rabadger]

Before you start find out what kind and size holes you have to put in the old foundation to extend your heating and air conditioning supply duct(s) and returns. Find out if your heating and cooling equipment will handle it.
Remember, when you make changes to a duct system by buy adding or changing ducts the air flow through the whole system if effected. Also if the equipment was sized correctly the first time and the SWAG method was not used, it may not be big enough.

If the new pushed out section is crawl space will you need a access point?
I am not an engineer but I have seen people make the mistake of cutting to much of the old foundation wall out then having problems.

Just trying to help.

[jello]

Thanks for the advice. The heating and AC is mounted on the roof, so the ducts are not in the crawl space. I was planning on cutting out a section no wider than 24" just to be on the safe side.

[VALENT]

what is the actual support made of? Stacked blocks, cmu's etc?