Home Energy Savings Act of 2021 This bill extends the nonbusiness energy property tax credit through 2031 and increases the credit percentage from 10% to 30% for qualified energy efficiency improvements. The bill also imposes a $1,200 annual limitation on the credit and limits for windows and doors. The bill allows a credit for 30% of the cost of home energy audits. A home energy audit is an inspection and written report for a taxpayer's principal residence that identifies the most significant and cost-effective energy efficiency improvements and is conducted and prepared by a certified home energy auditor. The bill also requires that energy property placed in service after 2023 be produced by a qualified manufacturer and that the taxpayer includes the qualified product identification number for such property on the return of tax.