Find a good local architect to design the home with you and help guide you through the entire process.

My suggestion is to start by learning about various alternative approaches, the pros/cons of each, and the value added by various professionals you may wish to have on your team. Katherine Salant's book, The Brand-New House Book: Everything You Need to Know About Planning, Designing and Building a Custom, Semi-Custom Or Production-Built House is the best written, most complete and least-biased homeowner resource I've found to date on the subject.

Best wishes for a successful project.

Thank you both!

Ask your lender if they have recommendations. Get a lender that specializes in renovations and construction and ask them

we started with the architect. If we had it to do over we’d start with the builder. Our lender recommended the builder. We’d find the builder and then see what architects they worked with.

we and 1 other we know didn’t have great luck with builders recommended by architects. In our case They wouldn’t even call us back. We were the luckier ones by far. The other case I know had huge heartache and several hundred k losses from the architect recommended builder. But of course that is only 2 people.

I am happy with our architect but in the end it was our builder that made our project possible and do able.

Design and construction are interrelated. Whichever route you go, you'll be best served by putting a team together that includes architect/designer and builder and having them collaborate from the outset. That way you don't end up with an expensive set of plans that doesn't get built. Here's another person's take on it:

https://www.finehomebuilding.com/2014/05/14/a-better-approach-to-designbuild

The sooner you get the builder and architect together on the project, the better.

We got suggestions of possible builders from our real estate agent while we were looking for land. We would ask one of the potential builders to join us when we toured a lot to get his take on its "buildability." It helped us to weigh the pros and cons of each lot, and we got to see how the builder thinks and works (i.e. did he only see problems with the lots, or did he see creative solutions too?). We did this with 3 builders, and ultimately chose our builder based on our immediate connection with him, his excitement over the possibilities of the lot we ultimately purchased, and his impeccable references from both past clients and subs.

After choosing our lot and our builder, he gave us the names of architects that he has worked with in the past and thought would be a good fit for our vision. We interviewed and chose one from his suggested list. Final plans are being drawn up, and we hope to break ground by the end of the summer.