Sometimes, e-mail sounds so impersonal. But I suggest you set some time aside and put together as professional as you can get, your proposal. Then, I'd USPS-mail it to Bob. If you were Bob, what would you like to see from someone wanting you to do a project at their house? This proposal is going to show the seriousness and the thought you put into your project. Without overwhelming Bob with details, supply as much general info such as costs, drawings, and materials as you can.
I'd then go to this site and ask 'Bob' what is the USPS mailing address for submitting your project to Bob. (Last I heard there was a 2-year wait but things change over time.) Ask Bob