Can manufactured homes qualify?
Manufactured homes can qualify for a $2,500 credit if they meet ENERGY STAR Labeled Home requirements.  (Source: Green Insight)
How have the existing 45L tax credits been expanded?
The tax credit increased from $2,000 currently (2021) for meeting outdated IECC reference to $2,500 for meeting ENERGY STAR and $5,000 for DOE Zero-Energy ready. (Source: Green Insight)
What are the requirements of DOE zero-energy ready?
DOE zero-energy ready includes Indoor airPlus and ENERGY STAR certification as a baseline but more stringent requirements for most components. (Source: Green Insight)
What builders are eligible?

Any ENERGY STAR registered builder qualifies. Becoming an ENERGY STAR partner is easy. Simply fill out an ENERGY STAR Partnership Agreement in this link. There is no cost to partner with ENERGY STAR or use ENERGY STAR promotional materials. (Source: Green Insight)

What types of construction are eligible for 45L?
Newly constructed homes or substantially renovated single-family detached, duplexes, townhouses, apartments, and condominiums are all eligible for the tax credit. Even occupancies such as assisted living and student housing projects are eligible. Market rate, affordable housing, and condominiums are all eligible. (Source: Green Insight)
Who can claim the 45L tax credit?

The qualified contractor – typically the developer, builder, or homeowner is the only person who can claim the 45L tax credit and must own the unit at the time of construction or improvement. (Source: Green Insight)