Another (?) 12'x16' Sobon Frame -- Getting Going

[blamblambunny]

First post

I've taken a class at Shelter Institute and have been doing a bunch of reading, and I'm convinced that, with some help here, I could build the 12'x16' frame from J. Sobon's book, "Timber Frame Construction." (I think it's also known as the Heartwood Class Frame, and a variation is in Will Beemer's book, too.) The problem is it's close but not quite what we're looking for: ideally we'd have an additional foot of headroom on the first floor, and there'd be a 3' kneewall in the loft (Sobon mentions this is doable with the timber sizing he specifies.)

So the question I have is, how do I go about starting this? "Fourteen Small Timber Frames" from the Guild has the plans for the basic structure, but I'm assuming I don't just wing-it, modifing the dimensions to get what we want That means either pulling out the drafting table (once upon a time I was an architecture student) or learning a lot more about SketchUp (which I think I'll be able to do -- I have some drafting experience) and generating some cutsheets.

And that's another question: given some plans for a frame, do you generally create cutsheets first, or should they flow right from the plans? At Shelter we were given cutsheets, which is nice, but I'm wondering if that's the norm. I'm assuming, also, that I should pass these designs along to an engineer to make sure I'm on the right bus and haven't designed something that's going to collapse on us when those winds pick up in Down East Maine. Thoughts?

Some time in the future I'll be asking about getting these designs past planning boards, too, because -- oooof, we've got one.

Thanks!

[Jim_Rogers]

It's my opinion that you should talk to the planning board now. Find out what they're going to want. Then work towards that goal. If you do your drawing now. And the don't comply with the planning board then you'll have to do them again.
Do them right the first time.

If they say the design needs to be stamped by a structural engineer then you need to get them on board.
You can't just draw the plans and say to a engineer, please stamp my plans. They won't do that. They need to oversee the drafting of the plans in order to comply with engineering license requirements.

Most experienced timber framing engineers are familiar with Jack Sobon's design as well as Will Beemer's book/design.
They'll just need to calculate the differences you have created by modifying the design. And they will need to see if your design will support the loads for your area. Such as snow load, and wind load.

The planning board or your building inspector may need your timbers to be grade stamped. If you're milling your own timbers, then you can get a traveling grader to come to your site and inspect your timbers. Not a huge problem to overcome.

Good luck with your project.

Jim Rogers

[blamblambunny]

> It's my opinion that you should talk to the planning board now.

Well that definitely sets me off in a different direction -- and thank you for explaining why that is. I think you just saved me a ton of time and effort.

My worst nightmare (as far as this project goes) is going to the board, telling them what we'd like to build, and they saying, "no, you can't build that, it's not a stick frame." There's no mention, explicitly at least, of timber framing in the State of Maine building code. I'm a little concerned. But talking to them early (and getting a contractor in the loop) sounds like the right way to go.

Thanks again, super helpful!

[Jim_Rogers]

There have been and are being built lots of timber frames in ME. 
You may just need to educate the planning board about how strong a timber frame is.

You could try and find a timber frame company near you and ask them if they had any trouble with your town's departments. 
They may have some advice for you.

Jim Rogers

[rusticretreater]

If you read the state building codes, you will probably find a statement  saying whatever is not covered in these building codes is covered by the National Building Codes and they should also cite which revision of the code is relevant.

The state offices should be more than familiar with timber frame buildings.

[blamblambunny]

> you will probably find a statement  saying whatever is not covered in these building codes is covered by the National Building Codes

Yup, that's what they say, but they actually refer to the international building codes rather than anything national:

"Engineered design in accordance with the International Building Code is permitted for buildings and structures, and parts thereof, included in the scope of this code." And...

"R301.1.2 Construction Systems
The requirements of this code are based on platform and balloon-frame construction for light-frame buildings. The requirements for concrete and masonry buildings are based on a balloon framing system. Other framing systems must have equivalent detailing to ensure force transfer, continuity and compatible deformations."

The folks I've talked to in Maine say that this is the code that allows for timber frame structures. My concern is that there are few/no timber frames on the island -- everything looks stick built, as far as I've seen -- which means I might have to teach the planning board about them. I think it's all doable but I'm still trying to figure out how to navigate, here

[Don P]

Sort of. Well, I see you caught it.
You mentioned planning board but we are all answering a question about the building department and codes.
What most people are familiar with is the IRC, the residential code
It is a prescriptive (cookbook) method of building typical stick frame residences.
The IRC is under the IBC, the building code which covers the entire built environment.
Whenever you step outside of the prescriptions of the IRC you enter the IBC (each state has their own names for these, in my state the IBC is the VCC, Virginia Construction Code) (Code= codified, written, law).
It is an engineered solution, only those items that are non prescriptive require engineering.

A timber frame is the same strength as a stick frame, hopefully, that is what the engineering is about. They are not designed to a higher strength. TF does lack the redundancy of stick, depending on how you define strength, redundancy is survivability, that is ultimately strength. If you lose a stud, no big deal, if you lose a post, big deal. I have had to educate young open mouthed inspectors, pointing out how it is all the same strength if the designer did his job properly.

Planning and zoning are what your neighbors want to see in their neighborhood. These are usually about use, setbacks and aesthetics rather than how a building is framed. The moment I've had clients think they are going to teach people who do this every day, they would be more than willing to teach you patience on your dime.

[blamblambunny]

@Dan P, did some reading and I think I get it now -- thanks very much for the summary. If I have this right (?) the planning board cares about where the structure goes and that it doesn't harm the neighbors, the island or anything else, and someone else cares that that structure was designed (in our case, engineered) and raised correctly?

And, because the IRC is prescriptive for stick-built structures, that second person should use the IBC (not the IRC) to evaluate it?

What's odd is, the town has their zoning ordinances available but I've never seen one for building code themselves. Does this mean we need to run the plans by someone at the county or state level?

Obviously I'm entirely new to all of this. Thanks -- this is a huge help.

[btulloh]

Usually you start with the department that issues building permits. Generally it starts and ends there as long as you’re building an appropriate structure for your lot. Check the current zoning of your parcel and see what is allowed to be built. That will include setbacks, use, etc.  Check to see what all has to be submitted with the application for the building permit. Usually that will include a plat with the location of your new structure and distances to lot lines.  Most localities offer a list of requirements or info packet for applying for building permits. These days that can probably be found on the county govt website. Or just go to the courthouse and ask where to obtain a building permit. Issuing building permits is a routine matter and they should be able easily give you the info you need. 

[JRWoodchuck]

For the most part any thing out of the norm at least for our building/planning dept will default to the engineer if he stamps it they usually are good to work with. 

[justjacob]

i'm also up in maine, in the portland area but am about to close on some land near augusta. i've been diving into codes and planning boards of many towns in this area and am willing to offer my help in the nitty gritty of identifying where the info you need is. i'll also bring over my tools and help you cut some timbers if you're interested. i'm also going to build a variation of the heartwood frame in the next year (need the land first) so am interested in diving in with you if you want.