I have finally finished design based on my interpretation of the building code (this will be my first design, build and first home). Now that I've estimated timber cost, I am looking for ways reduce it. I was careful about over engineering, but since this is my first design / build, I continue to doubt not only my understanding of code but the stability of its design. Below is link to my design in Google SketchUp ( Download Free Version Here ) format, I would really appreciate any feedback you guys could offer if willing.

http://www.thedigitaldatapimp.com/TinyHouse.skp

First Design

Only two lumber dimensions are used and both are dimensional yellow pine : 10x10 and 6x8

Thanks again!

Are you limited to certain sizes or lengths?
Have you read the TFG's joinery and design books (available on the website bookstore)?
Did you run beam calcs on all the pieces parts?
Are you planning a hand raising?
Snow loads?
What does the floor plan look like? (where are the kitchen, stairs, bathrooms, etc?)


A few thoughts:

Learn about components in SketchUp - they make modeling much easier.

You could probably save pieces and material by scrubbing the frame with an engineer or a TF designer. You have lots of wood, close together.

Do you have a high snow load? You have the common purlins on just over 2' centers. The 10x10 posts and rafters could probably go to 8x10 or 8x8 depending on the loading and material choice. The 10x top plate could likely go to 6x8 or 6x10. With the intermediate posts to the rafters, the rafter span is pretty short - so these are probably oversized.

Where will your stairs go? Figure this out early. Head height issues come into play in TF much more frequently than in conventional framing.

Will you have plumbing on the second floor? In floor lighting or heat? Think about this now.

You could save a bit by getting rid of the double girts @ floor level on the perimeter of the building. The girt can be an end joist and hold the bents together.

I'm not a fan of setting queen posts on horizontal timbers as you've shown. A post (at the outer walls) will shrink far less in length than the 10x will in cross section - which means you're frame will likely sag in the middle (especially in green oak - not sure how much yellow pine moves in comparison). Where possible run your posts up as long as you can get them. This may not work in the center of the house due to design - but you could simplify things a bit by going to a king post design (unless you are limited to short pieces from a local saw mill).


Hope this is a good start.

Are you limited to certain sizes or lengths?

24' @ 10x10 is the maximum length / dimension my local sawmill can handle.

Have you read the TFG's joinery and design books (available on the website bookstore)?

Nope, but I just bought it as it appears to bet this forums go to book. Thanks for the recommendation. I added you as the referrer on the order.

Did you run beam calcs on all the pieces parts?

Sure did, based on the Code Type IV for timber frame houses in N. America. I continue to doubt myself though. Guess thats normal for a first time build.

Snow loads?

Not likely. I'm 60 miles S. of Atlanta, GA. The largest snow I've seen in my 33 years was 2 inches... and it closed the entire city. Couldn't find bread or milk anywhere

I haven't decided on a stair system yet. Id like to do spiral but I am confused on the code that would allow it to reach up into the loft (which isn't 7'8" high or 36" wide and therefore wouldn't fit code requirements). Still deciding. Its designed on the principal that I can just remove two of the common perlins in one of the sections that would satisfy two 36" landing (top and bottom) and suitable staircase. Then a ladder for the loft.

I'll be building on a large and modern crawlspace. One large septic tank header and vertical stacked 1st/2nd floor bathrooms right next to the kitchen to minimize drain piping and supply lines.

Could you elaborate more on the queen post and vertical header? This is the only design I can see that will allow for an open 2nd floor along with a small loft that also stays within the 26' height requirement I have to stay within. I am very open to ideas that would save timber and keep the 2nd floor with the loft!

Pull the queens a little closer together to reduce the bending stress on the tie beam. But keep the queens near the ends of the collar, so raise the collar as well. And like Mike says, if you use material that shrinks a lot, the queens stacked on the tie beam is not the best idea. If you're using white pine or relcaimed material, it should be OK.

PS: You may find this page to be of interest:

http://www.northernlightstimberframing.com/su/

I received my books and have decided to redesign based on the information I've read thus far (which isn't even half the material yet). What an amazing reference for people to have.

Ill be switching to 8x8 for posts and 8x10 for headers. I'll also likely change the truss system and lose the upper loft. I should be able to design a better structure, with the same sq. footage at half the price! Well worth the cost of the books.

Thanks for the help guys. I appreciate it and will update the thread as necessary.