Hopefully this questions wont be to all encompassing and broad so that it wont make any sense.

Im trying to build a home in Southern Connecticut to be as energy efficient and cost effective as possible. My Dad is a Carpenter / Contractor so we will be doing it ourselves. He has never done anything “green” or energy efficient before so I have been researching as much as possible to find the most cost effective and energy saving way possible.

What I want to do so far.

Home will be Colonial, Gambrel style roof, 36 X 30, no garage

Basement will be concrete formes, floor poored over 4″ xps foam. Will seal basement walls with Spray insulation, 2 – 4″.

Framing walls will be double 2 X 4 stud, spray isulation inside wall, minimum 2 inches to form vapor barrier, rest will be filled with cellulose. Wall thickness will be 12 inches, should result in a R value of near 40.

Roof thickness will follow the same values as walls, utilizing gambrel roof style to save on Lumber and materials.

Exterior siding will be vinyl, due to cost. House wrap will not be vapor barrer due to it exisitng inside the home sheathing.

Hoping to accomplish heating and cooling with a mini split system with upstairs and downstairs units. I think I will also need a HRV due to the house envelope being very tight.

Now for the questions, is anything im doing totally wrong? Is there a cheaper, more effective way to do this? I think ive addressed most everything I can think of in ways that I can handle, and from browsing other projects that have been done on the site.

Lastly, will solar be worth it for me? Would solar hot water?

Thanks in advance

Denis