I installed some windows and a new doors to what it will be my house.

[jose-rdgz]

I bought this house last year and I've not lived there as of yet, but it will be my main house. I've been remodeling little by little. can still take the energy property credit?

[Opus 17]

You can claim the improvements on your main home.  It's ok if you make the improvements before you move in as long as you do move in and make it your main home.

Be aware that the credit is claimed as of the date of installation.  The credit currently expires 12/31/2020. For doors, windows and other insulating improvements, the credit is 10% of the materials cost, not including installation, and there is a $500 maximum credit amount per taxpayer, going back to when the credit was created in 2006.  So if you took it before, you will need those records or you might be maxed out already.