II 

110TH CONGRESS 

2D SESSION S. 3228 

To amend the Internal Revenue Code of 1986 to allow a credit for green 

roofs. 

IN THE SENATE OF THE UNITED STATES 

JULY 8, 2008 

Mr. SMITH (for himself and Ms. CANTWELL) introduced the following bill; 

which was read twice and referred to the Committee on Finance 

A BILL 

To amend the Internal Revenue Code of 1986 to allow a 

credit for green roofs. 

1 Be it enacted by the Senate and House of Representa2 tives of the United States of America in Congress assembled, 

3 SECTION 1. TAX CREDIT FOR GREEN ROOFS. 

4 (a) FINDINGS AND PURPOSE.— 

5 (1) FINDINGS.—Congress makes the following 

6 findings: 

7 (A) Green roofs reduce storm water run 

8 off. 

9 (B) Green roofs reduce heating and cooling 

10 loads on a building. 


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1 (C) Green roofs filter pollutants and car2 bon dioxide out of the air. 

3 (D) Green roofs filter pollutants and heavy 

4 metals out of rainwater. 

5 (E) Construction of green roofs has the po6 tential to reduce the size of heating, ventilation, 

7 and air conditioning equipment on new or retro8 fitted buildings resulting in capital and oper9 ational savings. 

10 (F) Green roofs have the potential to re11 duce the amount of standard insulation used. 

12 (G) After installation, green roofs can re13 duce sewage system loads by assimilating large 

14 amounts of rainwater. 

15 (H) Green roofs absorb air pollution, col16 lect airborne particulates, and store carbon. 

17 (I) Green roofs protect underlying roof ma18 terial by eliminating exposure to the sun’s ul19 traviolet radiation and extreme daily tempera20 ture fluctuations. 

21 (J) Green roofs reduce noise transfer from 

22 the outdoors. 

23 (K) Green roofs insulate a building from 

24 extreme temperatures, mainly by keeping the 

25 building interior cool in the summer. 


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1 (L) Green roofs provide habitat for bene2 ficial insects, such as honeybees and other polli3 nators, and small animals such as birds. 

4 (2) PURPOSE.—The purpose of this section is 

5 to encourage the construction of green roofs there6 by— 

7 (A) reducing rooftop temperatures and 

8 heat transfer; decreasing summertime indoor 

9 temperatures; 

10 (B) lessening pressure on sewer systems 

11 through the absorption of rainwater; 

12 (C) filtering pollution—including heavy 

13 metals and excess nutrients; 

14 (D) protecting underlying roof material; 

15 (E) reducing noise; 

16 (F) providing a habitat for birds and other 

17 small animals; 

18 (G) improving the quality of life for build19 ing inhabitants; and 

20 (H) reducing the urban heat island effect 

21 by decreasing rooftop temperatures. 

22 (b) GREEN ROOFS ELIGIBLE FOR ENERGY CRED23 IT.— 

24 (1) IN GENERAL.—Subparagraph (A) of section 

25 48(a)(3) of the Internal Revenue Code of 1986 is 


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1 amended by striking ‘‘or’’ at the end of clause (iii), 

2 by striking the period at the end of clause (iv) and 

3 inserting ‘‘, or’’, and by adding at the end the fol4 lowing new clause: 

5 ‘‘(v) a qualified green roof (as defined 

6 in section 25D(d)(4)(B)).’’. 

7 (2) CREDIT ALLOWED AGAINST ALTERNATIVE

8 MINIMUM TAX.—Subparagraph (B) of section 

9 38(c)(4) of such Code is amended by striking ‘‘and’’ 

10 at the end of clause (iii), by redesignating clause (iv) 

11 as clause (v), and by inserting after clause (iii) the 

12 following new clause: 

13 ‘‘(iv) so much of the credit determined 

14 under section 46 as is attributable to the 

15 credit determined under section 48, and’’. 

16 (3) EFFECTIVE DATE.—The amendments made 

17 by this subsection shall apply to periods after De18 cember 31, 2008, under rules similar to the rules of 

19 section 48(m) of the Internal Revenue Code of 1986 

20 (as in effect before the date of the enactment of the 

21 Revenue Reconciliation Act of 1990). 

22 (c) CREDIT FOR RESIDENTIAL GREEN ROOFS.— 

23 (1) IN GENERAL.— 

24 (A) ALLOWANCE OF CREDIT.—Section 

25 25D(a) of the Internal Revenue Code of 1986 


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1 (relating to allowance of credit) is amended by 

2 striking ‘‘and’’ at the end of paragraph (2), by 

3 striking the period at the end of paragraph (3) 

4 and inserting ‘‘, and’’, and by adding at the end 

5 the following new paragraph: 

6 ‘‘(4) 30 percent of the qualified green roof 

7 property expenditures made by the taxpayer during 

8 such year.’’. 

9 (B) LIMITATION.—Section 25D(b)(1) of 

10 such Code (relating to maximum credit) is 

11 amended by striking ‘‘and’’ at the end of sub12 paragraph (B), by striking the period at the 

13 end of subparagraph (C) and inserting ‘‘, and’’, 

14 and by adding at the end the following new sub15 paragraph: 

16 ‘‘(D) $2,000 with respect to any qualified 

17 green roof property expenditures.’’. 

18 (C) QUALIFIED GREEN ROOF PROPERTY

19 EXPENDITURES.—Section 25D(d) of such Code 

20 (relating to definitions) is amended by adding 

21 at the end the following new paragraph: 

22 ‘‘(4) QUALIFIED GREEN ROOF PROPERTY EX23 PENDITURE.— 

24 ‘‘(A) IN GENERAL.—The term ‘qualified 

25 green roof property expenditure’ means an exVerDate Aug 31 2005 00:18 Jul 09, 2008 Jkt 059200 PO 00000 Frm 00005 Fmt 6652 Sfmt 6201 E:\BILLS\S3228.IS S3228

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1 penditure for a qualified green roof which is in2 stalled on a building located in the United 

3 States and used as a residence by the taxpayer. 

4 ‘‘(B) QUALIFIED GREEN ROOF.—The term 

5 ‘qualified green roof’ means any green roof at 

6 least 40 percent of which is vegetated. 

7 ‘‘(C) GREEN ROOF.—The term ‘green roof’ 

8 means any roof which consists of vegetation and 

9 soil, or a growing medium, planted over a wa10 terproofing membrane and its associated com11 ponents, such as a protection course, a root 

12 barrier, a drainage layer, or thermal insulation 

13 and an aeration layer.’’. 

14 (D) MAXIMUM EXPENDITURES IN CASE OF

15 JOINT OCCUPANCY.—Section 25D(e)(4)(A) of 

16 such Code (relating to maximum expenditures) 

17 is amended by striking ‘‘and’’ at the end of 

18 clause (ii), by striking the period at the end of 

19 clause (iii) and inserting ‘‘, and’’, and by add20 ing at the end the following new clause: 

21 ‘‘(iv) $1,667 in the case of any quali22 fied green roof property expenditures.’’. 

23 (2) CREDIT ALLOWED AGAINST ALTERNATIVE

24 MINIMUM TAX.— 


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1 (A) IN GENERAL.—Subsection (c) of sec2 tion 25D of the internal Revenue Code of 1986 

3 is amended to read as follows: 

4 ‘‘(c) LIMITATION BASED ON AMOUNT OF TAX; 

5 CARRYFORWARD OF UNUSED CREDIT.— 

6 ‘‘(1) LIMITATION BASED ON AMOUNT OF

7 TAX.—In the case of a taxable year to which section 

8 26(a)(2) does not apply, the credit allowed under 

9 subsection (a) for the taxable year shall not exceed 

10 the excess of— 

11 ‘‘(A) the sum of the regular tax liability 

12 (as defined in section 26(b)) plus the tax im13 posed by section 55, over 

14 ‘‘(B) the sum of the credits allowable 

15 under this subpart (other than this section) and 

16 section 27 for the taxable year. 

17 ‘‘(2) CARRYFORWARD OF UNUSED CREDIT.— 

18 ‘‘(A) RULE FOR YEARS IN WHICH ALL

19 PERSONAL CREDITS ALLOWED AGAINST REG20 ULAR AND ALTERNATIVE MINIMUM TAX.—In 

21 the case of a taxable year to which section 

22 26(a)(2) applies, if the credit allowable under 

23 subsection (a) exceeds the limitation imposed by 

24 section 26(a)(2) for such taxable year reduced 

25 by the sum of the credits allowable under this 


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1 subpart (other than this section), such excess 

2 shall be carried to the succeeding taxable year 

3 and added to the credit allowable under sub4 section (a) for such succeeding taxable year. 

5 ‘‘(B) RULE FOR OTHER YEARS.—In the 

6 case of a taxable year to which section 26(a)(2) 

7 does not apply, if the credit allowable under 

8 subsection (a) exceeds the limitation imposed by 

9 paragraph (1) for such taxable year, such ex10 cess shall be carried to the succeeding taxable 

11 year and added to the credit allowable under 

12 subsection (a) for such succeeding taxable 

13 year.’’. 

14 (B) CONFORMING AMENDMENTS.— 

15 (i) Section 23(b)(4)(B) of the Internal 

16 Revenue Code of 1986 is amended by in17 serting ‘‘and section 25D’’ after ‘‘this sec18 tion’’. 

19 (ii) Section 24(b)(3)(B) of such Code 

20 is amended by striking ‘‘and 25B’’ and in21 serting ‘‘, 25B, and 25D’’. 

22 (iii) Section 25B(g)(2) of such Code is 

23 amended by striking ‘‘section 23’’ and in24 serting ‘‘sections 23 and 25D’’. 


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1 (iv) Section 26(a)(1) of such Code is 

2 amended by striking ‘‘and 25B’’ and in3 serting ‘‘25B, and 25D’’. 

4 (3) EFFECTIVE DATE.— 

5 (A) IN GENERAL.—The amendments made 

6 by this subsection shall apply to property placed 

7 in service after December 31, 2008, in taxable 

8 years ending after such date. 

9 (B) APPLICATION OF EGTRRA SUNSET.— 

10 The amendments made by clauses (i) and (ii) of 

11 paragraph (2)(B) shall be subject to title IX of 

12 the Economic Growth and Tax Relief Reconcili13 ation Act of 2001 in the same manner as the 

14 provisions of such Act to which such amend15 ments relate. 

Æ 


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