Newbee question

[JohnJ]

Hello to all.  We recently bought a log home in eastern Tennessee.  We have a large porch on the west side and I want to add a room to the house that connects to this porch.  I had thought about attending log building schools, timber building schools and have looked at various sites with plans.  I like the Little House plans and am thinking of buying those.

My concerns are

1) I'd like to end up with a structure that is 18 x 16, one story with gable roof and a loft 9for storage and sleeping).  If I buy the Little House Plan for the 14 x 24, can I modify it?

2)  Foundations scare me.  The ground adjacent to the porch is flat but I have no clue what type of dirt it is.  I was hoping to do what this gentleman did here: http://www.bellsouthpwp.net/n/i/nibblet/land/cabin/foundation.html   since it seems relatively simple.  Hoping there's someone here from east TN . . . Will this type of foundation work? 

3)  I saw a note on the Order Form that said the Little House Plan may not meet local codes.  As I understand it, my county (Carter County, TN) just adopted the International Code . . . whatever that is.  I wrote to Mr Raabe asking his opinion on this but if there's anyone here from east TN, I'd like to hear your thoughts on possible issues.

I'm sure my questions will become more intelligent as i elarn more, but right now I'm just trying to figure out where to start.  Thanks in advance for any help.

[MountainDon]

   JohnJ. 

A question for you. What is the foundation of the existing building?

If your county has adopted the IRC in it's entirety there is a good chance they will not accept the type of foundation you referenced. Pier and beam foundations are not prescriptively addressed in the IRC.

It will help your planning process immensely if you can call them and determine what version of the code they have adopted. IRC2009 is the latest release. Also find out if the addition will create any sizing difficulties to the septic system if one is used. Extra sleeping space may trigger something there depending on the current septic capacity. Also ask about electrical permits for a DIY. Ditto plumbing. It helps a lot to know all the requirements, all the hoops that must be jumped through, before planning gets too far along.

[JohnJ]

Thanks MountainDon.  I will call tomorrow and use your list of issues as a start.

I'm not sure what the terms are, but in our house, the bottom log of each wall sits on a raised concrete foundation which runs the perimeter of the house.   There is a crawlspace underneath large enough for workmen . . . about 24" - 30"
but you can't see under the house unless you're under there.

There are three houses nearby.  Two have blocks under the house.  They also sit 24"-30" above ground level and you can see underneath the house (no perimeter foundation).

The third has no foundation visible.  The brick facing meets the grass.

Our home was built in 1982 so I assume these other homes also date from the early 80s.  I've been told there was no code here and one was just adopted.

[MountainDon]

Sounds like the existing house has a full perimeter foundation, probably on a concrete footing that is also full perimeter.  You probably consider doing the same type, dug to the same depth. You might have to dig a little test hole beside the existing foundation to check depth.

[Don_P]

Look closely at the bottom 2 rows of "logs" and see if they aren't log siding. If so look under the crawlspace and you should be looking at the dimensional lumber floor joists sitting on the foundation wall. The log siding on the bottom rows in the type I'm describing is covering the floor rim. If it is a milled log home, matching log siding is usually available.

Although you want to be at least as deep as the existing foundation do ask what the footing depth needs to be currently. Your first inspection is usually footing trenches dug, and formed if needed, rebar in place and ready to pour.