Hi all,

I bought a set of CP plans and am looking at how to adapt them to what I want to do. I'm trying to understand the relationship between a set of plans and detailing them for construction in a safe way (since I was hoping to modify them a bit). I mean, I could do it crudely, but I don't know all of the engineering details about load-bearing and weight distribution, etc. My first inclination is to think that I would need to hire a structural engineer for this- Am I missing something?! 

Any info/clarification is much appreciated. Thanks!!!

Working with a local builder or engineer to customize the plans for your land, needs, and to make sure you're up to local codes, etc. is definitely recommended.

Thank you, Adam. Is that what CP members are doing (eg, hiring an engineer)? Or are most folks making adjustments and then posting them to flush it out with other experienced members? 

The whole range. Some folks go straight to a RDP (registered design pro, architect or engineer) some do it themselves and some ask for input here and elsewhere. Some of that depends on where you are building and their requirements. When most of us talk about building to code we are referring to the IRC, the prescriptive residential code. Basically it is written so that if you stick to its prescriptive methods you do not need an engineer in most places. Any elements that step outside of those prescriptive means or methods do require engineering. If you post what you have come up with, rough location, required snow loads and frost depths I'm sure you'll get some input.

Well said Don.  It is good to discuss what the inspector or building department is requiring. Sometimes it is easy to reason with them. If you show that you are knowledgeable and are going to be safe they might relax a requirement. However, there are times when you just have to back-off, do what they want, and fix it later. They often think they are the last word and to be fair they have alot of responsibility. They are not always the best way. One can exceed requirements and save money, time, or both.

The case I always remember was a garage with upstairs living. The builder did not know how to engineer a footing that could be flush with a garage floor. The finished plans showed an 8 inch high footing (above grade) in some places of the garage floor. The county required an engineer stamp to be flush. The engineer just found a link to the county building department that showed how to build this. He charged 100$ for the time to save the homeowner, the builder, and the building department from embarrassment.

Quote from: Don_P on June 16, 2020, 08:01:06 AM
The whole range. Some folks go straight to a RDP (registered design pro, architect or engineer) some do it themselves and some ask for input here and elsewhere. Some of that depends on where you are building and their requirements. When most of us talk about building to code we are referring to the IRC, the prescriptive residential code. Basically it is written so that if you stick to its prescriptive methods you do not need an engineer in most places. Any elements that step outside of those prescriptive means or methods do require engineering. If you post what you have come up with, rough location, required snow loads and frost depths I'm sure you'll get some input.

Thanks Don, that was just the answer I needed! That totally clarified it for me. I'm off to study IRC 

Chelan County, WA building dept said I needed a structural engineer to approve the structure and trusses, when I took these plans I bought to an engineer, he said that WA state law forbids them from certifying plans made by someone else,so he would have to totally re-do all the plans himself.   Is this true,does that law exist or does he just want to charge me more than is necessary by totally redoing the plans himself?  He quoted me $2k to redo the plans with structure approval, does that seem like a good price?  Thank you

Update: my engineer said that due to the good detail level on the CP plans, it saved me $250 from his normal cost, so that is good (the cost of the plans recouped).