Most areas require a set of detailed plans that have been signed off by a structural engineer for a project this big. You have alot of options on who can make the plans, architects, residential designers, engineering firms, design/build contractors, etc.

If it was me and I knew pretty much what I wanted, I would get some home design software and start playing. Once you get a pretty good idea of what you want, and you have a picture in hand you can ask the draftsman, how much (and be much cheaper than going in empty handed)? If you have a contractor in mind, I would probably bring them by during the design process. A lot of times, a bathroom or stairs location can have huge impact on the overall costs of an addition project. You can then decide if its worth the $$$ to have the bathroom in one location vs another.

Don't waste your time. Find an sole-practitioner architect (a real one, not a draftsman) who charges by the hour and get a basic plan and structure worked out quickly then give it to a builder. It'll save you money and aggravation later.

You won't get an accurate quote from builders without a plan. And the quote won't be really accurate unless the plan is fairly detailed. At a minimum, get a list written of the specifics of what you want in this addition/remodel. I'd suggest using an architect, too, and I agree about a sole practitioner. They can price their work either by the hour or by the job. If all you want is a plan, I'd suggest going by the hour. If you use an architect, make sure that they allow for 2-3 revisions as part of their basic package.

If you are living with a budget amt in your head, plan on 20% extra for overages.

It'll cost more than you ever dreamed no matter who you use. SO you might as well use someone who is qualified. Get an architect involved.

Architect.

Here is a link that might be useful: lbum

thanks for the advice guys, I think i'm going to start with some software, them move onto an architect.

I am a couple of months ahead of you with a similar addition. In order to get real quotes from contractors (not just ballparks), you will need to have a set of plans.

We interviewed 2 architects and 1 draftsman. Since we already had such a clear vision of what we wanted, we were able to convey that vision to each of them. First arch: $21K. Second arch: $11K. Draftsman: $3700

We went with the draftsman, who is highly experienced with remodels and custom builds. So far, we have been very happy with the plans he has worked up for us and he has been very thorough, coming to the house multiple times for accurate measurements, double-checking roof pitches, etc.

We figured that, if in the end the plan needs some re-work and we feel stumped, we can bring what has already been done to an architect for final revisions.

He is providing all necessary plans for approval submission. The one thing we won't get from him are the useful interior renderings that the architects would have done.

Our final revisions (the price included 3 revisions) are going back to him in about a week and then we will be able to start interviewing contractors.

Hope this helps! Good luck!

Since you are building on top of your existing structure I would have a structural engineer take a look and see if your existing foundation and first level will be able to support the second story.

I also agree with having an architect involved in the process.

We were going to do a "simple" kitchen remodel till I realized I didn't like where the kitchen is located in our 1959 ranch and will have to do a small addition and renovations to the existing space. We've hired an architect and she has been amazing. A good architect will listen to your needs and be able to show you what you can do (and you can avoid the cookie-cutter look).

We are in the process of hiring a contractor. We asked our architect for suggestions of who she's worked with and trusts. We are using her initial sketch from the consultation meeting to provide to contractors, along with her description of the project to get an idea of cost. We are also having her team do exact measurements and provide us with a schematic design package which will include a floor plan, front, rear and side elevations. We will also share this with the contractors and it will enable them to give us a better idea of cost.

Also, depending on your local government (in my case, the county) they have certain requirements for the permits you will need to do this work. You are going to want to make sure you have the type and detail the local government requires in order to get your permit.

For example, my county requires 2 sets of construction documents drawn to scale with sufficient clarity and detail to show the nature and character of the work to be performed, including, but not limited to: plans of each floor level, 4 elevations and typical cross section; and 7 copies of plot plans or 2 copies of the approved site development plan as required by the county regulations.

If and when you go to sell your home you want to be able to show to prospective buyers that you did your due diligence and that the renovation was done correctly. We weren't going to purchase our house unless I had proof that for the addition added in the 80's went through the proper process and the county issued the permits and approvals for the work.

What I found interesting was that the county no longer had this information and it was up to the owner(s) to maintain the documentation that the proper permits were secured and the work had passed inspection. Luckily the PO had kept all the necessary documents.

I also suggest checking out the series of "Not So Big House" books by Sarah Susanka. She has very interesting ideas regarding space and how to live in it.

Best of luck!

Here is a link that might be useful: Not So Big House