A bill to amend the Internal Revenue Code of 1986 to allow a credit for green roofs.

SECTION 1. TAX CREDIT FOR GREEN ROOFS.

    (a) Findings and Purpose.--
            (1) Findings.--Congress makes the following findings:
                    (A) Green roofs reduce storm water run off.
                    (B) Green roofs reduce heating and cooling loads on 
                a building.
                    (C) Green roofs filter pollutants and carbon 
                dioxide out of the air.
                    (D) Green roofs filter pollutants and heavy metals 
                out of rainwater.
                    (E) Construction of green roofs has the potential 
                to reduce the size of heating, ventilation, and air 
                conditioning equipment on new or retrofitted buildings 
                resulting in capital and operational savings.
                    (F) Green roofs have the potential to reduce the 
                amount of standard insulation used.
                    (G) After installation, green roofs can reduce 
                sewage system loads by assimilating large amounts of 
                rainwater.
                    (H) Green roofs absorb air pollution, collect 
                airborne particulates, and store carbon.
                    (I) Green roofs protect underlying roof material by 
                eliminating exposure to the sun's ultraviolet radiation 
                and extreme daily temperature fluctuations.
                    (J) Green roofs reduce noise transfer from the 
                outdoors.
                    (K) Green roofs insulate a building from extreme 
                temperatures, mainly by keeping the building interior 
                cool in the summer.
                    (L) Green roofs provide habitat for beneficial 
                insects, such as honeybees and other pollinators, and 
                small animals such as birds.
            (2) Purpose.--The purpose of this section is to encourage 
        the construction of green roofs thereby--
                    (A) reducing rooftop temperatures and heat 
                transfer; decreasing summertime indoor temperatures;
                    (B) lessening pressure on sewer systems through the 
                absorption of rainwater;
                    (C) filtering pollution--including heavy metals and 
                excess nutrients;
                    (D) protecting underlying roof material;
                    (E) reducing noise;
                    (F) providing a habitat for birds and other small 
                animals;
                    (G) improving the quality of life for building 
                inhabitants; and
                    (H) reducing the urban heat island effect by 
                decreasing rooftop temperatures.
    (b) Green Roofs Eligible for Energy Credit.--
            (1) In general.--Subparagraph (A) of section 48(a)(3) of 
        the Internal Revenue Code of 1986 is amended by striking ``or'' 
        at the end of clause (iii), by striking the period at the end 
        of clause (iv) and inserting ``, or'', and by adding at the end 
        the following new clause:
                            ``(v) a qualified green roof (as defined in 
                        section 25D(d)(4)(B)).''.
            (2) Credit allowed against alternative minimum tax.--
        Subparagraph (B) of section 38(c)(4) of such Code is amended by 
        striking ``and'' at the end of clause (iii), by redesignating 
        clause (iv) as clause (v), and by inserting after clause (iii) 
        the following new clause:
                            ``(iv) so much of the credit determined 
                        under section 46 as is attributable to the 
                        credit determined under section 48, and''.
            (3) Effective date.--The amendments made by this subsection 
        shall apply to periods after December 31, 2008, under rules 
        similar to the rules of section 48(m) of the Internal Revenue 
        Code of 1986 (as in effect before the date of the enactment of 
        the Revenue Reconciliation Act of 1990).
    (c) Credit for Residential Green Roofs.--
            (1) In general.--
                    (A) Allowance of credit.--Section 25D(a) of the 
                Internal Revenue Code of 1986 (relating to allowance of 
                credit) is amended by striking ``and'' at the end of 
                paragraph (2), by striking the period at the end of 
                paragraph (3) and inserting ``, and'', and by adding at 
                the end the following new paragraph:
            ``(4) 30 percent of the qualified green roof property 
        expenditures made by the taxpayer during such year.''.
                    (B) Limitation.--Section 25D(b)(1) of such Code 
                (relating to maximum credit) is amended by striking 
                ``and'' at the end of subparagraph (B), by striking the 
                period at the end of subparagraph (C) and inserting ``, 
                and'', and by adding at the end the following new 
                subparagraph:
                    ``(D) $2,000 with respect to any qualified green 
                roof property expenditures.''.
                    (C) Qualified green roof property expenditures.--
                Section 25D(d) of such Code (relating to definitions) 
                is amended by adding at the end the following new 
                paragraph:
            ``(4) Qualified green roof property expenditure.--
                    ``(A) In general.--The term `qualified green roof 
                property expenditure' means an expenditure for a 
                qualified green roof which is installed on a building 
                located in the United States and used as a residence by 
                the taxpayer.
                    ``(B) Qualified green roof.--The term `qualified 
                green roof' means any green roof at least 40 percent of 
                which is vegetated.
                    ``(C) Green roof.--The term `green roof' means any 
                roof which consists of vegetation and soil, or a 
                growing medium, planted over a waterproofing membrane 
                and its associated components, such as a protection 
                course, a root barrier, a drainage layer, or thermal 
                insulation and an aeration layer.''.
                    (D) Maximum expenditures in case of joint 
                occupancy.--Section 25D(e)(4)(A) of such Code (relating 
                to maximum expenditures) is amended by striking ``and'' 
                at the end of clause (ii), by striking the period at 
                the end of clause (iii) and inserting ``, and'', and by 
                adding at the end the following new clause:
                            ``(iv) $1,667 in the case of any qualified 
                        green roof property expenditures.''.
            (2) Credit allowed against alternative minimum tax.--
                    (A) In general.--Subsection (c) of section 25D of 
                the internal Revenue Code of 1986 is amended to read as 
                follows:
    ``(c) Limitation Based on Amount of Tax; Carryforward of Unused 
Credit.--
            ``(1) Limitation based on amount of tax.--In the case of a 
        taxable year to which section 26(a)(2) does not apply, the 
        credit allowed under subsection (a) for the taxable year shall 
        not exceed the excess of--
                    ``(A) the sum of the regular tax liability (as 
                defined in section 26(b)) plus the tax imposed by 
                section 55, over
                    ``(B) the sum of the credits allowable under this 
                subpart (other than this section) and section 27 for 
                the taxable year.
            ``(2) Carryforward of unused credit.--
                    ``(A) Rule for years in which all personal credits 
                allowed against regular and alternative minimum tax.--
                In the case of a taxable year to which section 26(a)(2) 
                applies, if the credit allowable under subsection (a) 
                exceeds the limitation imposed by section 26(a)(2) for 
                such taxable year reduced by the sum of the credits 
                allowable under this subpart (other than this section), 
                such excess shall be carried to the succeeding taxable 
                year and added to the credit allowable under subsection 
                (a) for such succeeding taxable year.
                    ``(B) Rule for other years.--In the case of a 
                taxable year to which section 26(a)(2) does not apply, 
                if the credit allowable under subsection (a) exceeds 
                the limitation imposed by paragraph (1) for such 
                taxable year, such excess shall be carried to the 
                succeeding taxable year and added to the credit 
                allowable under subsection (a) for such succeeding 
                taxable year.''.
                    (B) Conforming amendments.--
                            (i) Section 23(b)(4)(B) of the Internal 
                        Revenue Code of 1986 is amended by inserting 
                        ``and section 25D'' after ``this section''.
                            (ii) Section 24(b)(3)(B) of such Code is 
                        amended by striking ``and 25B'' and inserting 
                        ``, 25B, and 25D''.
                            (iii) Section 25B(g)(2) of such Code is 
                        amended by striking ``section 23'' and 
                        inserting ``sections 23 and 25D''.
                            (iv) Section 26(a)(1) of such Code is 
                        amended by striking ``and 25B'' and inserting 
                        ``25B, and 25D''.
            (3) Effective date.--
                    (A) In general.--The amendments made by this 
                subsection shall apply to property placed in service 
                after December 31, 2008, in taxable years ending after 
                such date.
                    (B) Application of egtrra sunset.--The amendments 
                made by clauses (i) and (ii) of paragraph (2)(B) shall 
                be subject to title IX of the Economic Growth and Tax 
                Relief Reconciliation Act of 2001 in the same manner as 
                the provisions of such Act to which such amendments 
                relate.

Summary: Amends the Internal Revenue Code to allow: (1) an 10% energy tax credit for the installation of a qualified green roof; and (2) a residential energy efficient tax credit for 30% of qualified green roof property expenditures up to $2,000. Defines a "qualified green roof" as any green roof which is at least 40% vegetated. Defines "green roof" as any roof which consists of vegetation and soil, or a growing medium, planted over a waterproofing membrane and its associated components.