‘‘(1) DOLLAR AMOUNTS IN CASE OF JOINT OC-
CUPANCY.—In the case of any dwelling unit which if
jointly occupied and used during any calendar year
as a residence by 2 or more individuals the following
shall apply:
‘‘(A) The amount of the credit allowable
under subsection (a) by reason of expenditures
made during such calendar year by any of such
individuals with respect to such dwelling unit
shall be determined by treating all of such indi-
viduals as 1 taxpayer whose taxable year is
such calendar year.
‘‘(B) There shall be allowable with respect
to such expenditures to each of such individ-
uals, a credit under subsection (a) for the tax-
able year in which such calendar year ends in
an amount which bears the same ratio to the
amount determined under subparagraph (A) as
the amount of such expenditures made by such
individual during such calendar year bears to
the aggregate of such expenditures made by all
of such individuals during such calendar year.
‘‘(2) TENANT-STOCKHOLDER IN COOPERATIVE
HOUSING CORPORATION.—In the case of an individ-
ual who is a tenant-stockholder (as defined in sec-
tion 216) in a cooperative housing corporation (as
defined in such section), such individual shall be
treated as having made his tenant-stockholder’s pro-
portionate share (as defined in section 216(b)(3)) of
any expenditures of such corporation.
‘‘(3) CONDOMINIUMS.—
‘‘(A) IN GENERAL.—In the case of an indi-
vidual who is a member of a condominium man-
agement association with respect to a con-
dominium which he owns, such individual shall
be treated as having made his proportionate
share of any expenditures of such association.
‘‘(B) CONDOMINIUM
MANAGEMENT
ASSO-
CIATION.—For purposes of this paragraph, the
term ‘condominium management association’
means an organization which meets the require-
ments of paragraph (1) of section 528(c) (other
than subparagraph (E) thereof) with respect to
a condominium project substantially all of the
units of which are used as residences.
‘‘(4) JOINT OWNERSHIP OF ENERGY ITEMS.—
‘‘(A) IN GENERAL.—Any expenditure oth-
erwise qualifying as a residential energy prop-
erty expenditure shall not be treated as failing
to so qualify merely because such expenditure
was made with respect to 2 or more dwelling
units.
‘‘(B) LIMITS
APPLIED
SEPARATELY.—In
the case of any expenditure described in sub-
paragraph (A), the amount of the credit allow-
able under subsection (a) shall (subject to para-
graph (1)) be computed separately with respect
to the amount of the expenditure made for each
dwelling unit.
‘‘(5) ALLOCATION IN CERTAIN CASES.—
‘‘(A) IN GENERAL.—Except as provided in
subparagraph (B), if less than 80 percent of
the use of an item is for nonbusiness purposes,
only that portion of the expenditures for such
item which is properly allocable to use for non-
business purposes shall be taken into account.
For purposes of this paragraph, use for a swim-
ming pool shall be treated as use which is not
for nonbusiness purposes.
‘‘(B) SPECIAL RULE FOR VEHICLES.—For
purposes of this section and section 48A, a ve-
hicle shall be treated as used entirely for busi-
ness or nonbusiness purposes if the majority of
the use of such vehicle is for business or non-
business purposes, as the case may be.
‘‘(6) WHEN EXPENDITURE MADE; AMOUNT OF
EXPENDITURE.—
‘‘(A) IN GENERAL.—Except as provided in
subparagraph (B), an expenditure with respect
to an item shall be treated as made when the
original installation of the item is completed.
‘‘(B) EXPENDITURES PART OF BUILDING
CONSTRUCTION.—In the case of an expenditure
in connection with the construction of a struc-
ture, such expenditure shall be treated as made
when the original use of the constructed struc-
ture by the taxpayer begins.
‘‘(C) AMOUNT.—The amount of any ex-
penditure shall be the cost thereof.
‘‘(7) PROPERTY FINANCED BY SUBSIDIZED EN-
ERGY FINANCING.—
‘‘(A) REDUCTION
OF
EXPENDITURES.—
For purposes of determining the amount of res-
idential energy property expenditures made by
any individual with respect to any dwelling unit,
there shall not be taken in to account expendi-
tures which are made from subsidized energy fi-
nancing (as defined in section 48A(g)(1)).
‘‘(B) DOLLAR LIMITS REDUCED.—The ap-
propriate subparagraph of subsection (b)(1)
shall be applied with respect to such dwelling
unit for any taxable year of such taxpayer by
reducing each dollar amount contained in such
subparagraph by an amount equal to the sum
of—
‘‘(i) the amount of the expenditures
which were made by the taxpayer during
such taxable year with respect to such
dwelling unit and which were not taken
into account by reason of subparagraph
(A), and
‘‘(ii) the amount of any Federal,
State, or local grant received by the tax-
payer during such taxable year which was
used to make residential energy property
expenditures with respect to the dwelling
unit and which was not included in the
gross income of such taxpayer.
‘‘(e) BASIS ADJUSTMENTS.—For purposes of this
subtitle, if a credit is allowed under this section for any
expenditure with respect to any property, the increase in
the basis of such property which would (but for this sub-
section) result from such expenditure shall be reduced by
the amount of the credit so allowed.
‘‘(f) APPLICATION OF SECTION.—
‘‘(1) IN GENERAL.—Except as otherwise pro-
vided in this subsection, this section shall apply to
expenditures made after December 31, 1998, and
before January 1, 2004.
‘‘(2) FUEL CELLS.—This section shall apply to
expenditures attributable to fuel cells which are
made after December 31, 1999, and before January
1, 2005.
‘‘(3) PHOTOVOLTAIC PROPERTY.—This section
shall apply to expenditures attributable to photo-
voltaic property which are made after December 31,
1998, and before January 1, 2006.
‘‘(4) NEW, HIGHLY ENERGY-EFFICIENT PRIN-
CIPAL RESIDENCE.—This section shall apply to ex-
penditures attributable to new, highly energy-effi-
cient principal residences acquired (within the mean-
ing of section 72(t)(8)(D)(iii)) after December 31,
1998, and before January 1, 2006.
‘‘(5) HIGHLY
EFFICIENT
PASSENGER
VEHI-
CLES.—This section shall apply to vehicles pur-
chased after December 31, 1998, and before Janu-
ary 1, 2010.’’.
(b) CONFORMING AMENDMENTS.—
(1) Subsection (a) of section 1016 of such Code
is amended by striking ‘‘and’’ at the end of para-
Revenue Code of 1986 shall be applied as if such sub-
section had never been enacted.
(c) EFFECTIVE DATE.—The amendment made by
subsection (a) shall take effect as if included in the
amendments made by section 9010(b) of the Transpor-
tation Equity Act for the 21st Century.
SEC. 5. EXTENSION OF CREDIT FOR ELECTRICITY PRO-
DUCED 
FROM 
CERTAIN 
RENEWABLE 
RE-
SOURCES.
Paragraph (3) of section 45(c) of the Internal Reve-
nue Code of 1986 (definitions relating to electricity pro-
duced from certain renewable resources) is amended by
striking ‘‘July 1, 1999’’ and inserting ‘‘July 1, 2004.’’.
Æ