Inflation Reduction Act and New Construction

This is a nuanced answer.   There are two types of Credits. 

The first is the Energy Efficient Home Improvement Credit.   Under the  Energy Efficient Home Improvement Credit: a taxpayer can claim the credit only for qualifying expenditures incurred for an existing home or for an addition to or renovation of an existing home, and not for a newly constructed home.  The expenses may qualify if they meet requirements detailed on energy.gov:.  They include:

• Exterior doors, windows, skylights and insulation materials
• Central air conditioners, water heaters, furnaces, boilers and heat pumps
• Biomass stoves and boilers
• Home energy audits

The amount of the credit you can take is a percentage of the total improvement expenses in the year of installation:

• 2022: 30%, up to a lifetime maximum of $500
• 2023 through 2032: 30%, up to a maximum of $1,200 (biomass stoves and boilers have a separate annual credit limit of $2,000), no lifetime limit

The second is the Residential Clean Energy Property Credit.  Under the residential Clean Energy Property Credit: a taxpayer can claim the credit for qualifying expenditures incurred for either an existing home or a newly constructed home.

These expenses may qualify if they meet requirements detailed on energy.gov:

• Solar, wind and geothermal power generation
• Solar water heaters
• Fuel cells
• Battery storage (beginning in 2023)

The amount of the credit you can take is a percentage of the total improvement expenses in the year of installation:

• 2022 to 2032: 30%, no annual maximum or lifetime limit
• 2033: 26%, no annual maximum or lifetime limit
• 2034: 22%, no annual maximum or lifetime limit

See:  https://www.irs.gov/credits-deductions/home-energy-tax-credits