It depends -- on your budget, your idea of "well designed" and your size requirements.

A very simple 2 floor, square plan, is typically the least costly and the most energy efficient, but unpleasing to the eye for many.

I would advise finding a builder who shares your vision, and has experience building this type of house. Building science has come a long way in the past few years and many builders have not kept up.

There is plenty of information available on the web, and I suggest you start reading. Educating yourself will help you throughout the process.

On budget, ours is 140-150. Well designed meaning energy efficient, bright spaces that flow.You are right about the not keeping up. Most builders in our area are building uninspired boxes on ever smaller lots. I'm up on pretty much all building systems including concrete sandwich which is very cool but unaffordable( Tilt up poured on site). Probably overkill for Vancouver Island. We have the property and will general the job ourselves to keep cost down. Thanks for your input. Steve

Example

Check out https://www.youtube.com/user/lavardera/videos

and http://blog.lamidesign.com/

The Learning from Swedish Home Building series. Lavardera explains a wall design that is easy to understand for a conventional builder, and addresses the shortcomings of standard 2x construction.

Building efficient means building tight and getting the details right. A house is a system and all the components must work together. Relying on typical crews to build to your specs will be tough, they simply won't understand the big picture and how important their part is.

Good luck!