with reference to the drawings , and in particular to fig1 and 2 , the height adjustable vanity of the present invention is generally indicated by reference numeral 10 . the unit preferably includes a single basin sink 12 having a faucet f , a countertop 14 and a lower cabinet 16 comprising a base portion , although a multiple compartment sink such as a kitchen sink may also easily be accommodated , as shown in fig9 and 10 . cabinet 16 preferably includes two doors 18 . as shown in fig2 doors 18 open to the sides , and preferably within the area defined by cabinet 16 , to accommodate a person in a wheelchair w . a cross piece 19 extends across the top of the opening defined by doors 18 , fixedly attached on its ends to walls 22 , 24 . extending between the bottom of countertop 14 and cross piece 19 is a roller shade 20 . as shown in fig8 a spool assembly 21 of roller shade 20 is attached to the bottom of countertop 14 , and the opposite end of roller shade 20 is attached to the top of cross piece 19 . referring to fig3 and 4 , it may be seen that cabinet 16 includes a right wall 22 , a left wall 24 and a rear wall 26 . in addition , as may also be seen in fig1 and 2 , downwardly depending from and fixedly attached to the ends of countertop 14 are right and left side drop panels 28 , 30 , respectively . right side drop panel 28 overlies right wall 22 of cabinet 16 , and left side drop panel 30 overlies left wall 24 of cabinet 16 . side drop panels 28 , 30 are maintained in a spaced , sliding relationship with walls 24 , 26 , respectively , by spacers 32 . all supply and drain plumbing is protected by a shroud 34 attached to and projecting from rear wall 26 . shroud 34 protects the supply and drain plumbing from the hardware attached to wheelchair w , and protects the legs of the person using wheelchair w from the plumbing supply and drain lines . the protected plumbing includes hot and cold water supply lines 36 , which pass through rear wall 26 at openings 37 and lead to faucet f , and drain assembly 38 , including p - trap 40 and height adjustable standpipe 42 . water supply lines 36 are preferably made of flexible tubing that complies with local building code requirements . the preferred construction of height adjustable standpipe 42 is disclosed in the copending application ser . no . 08 / 811 , 832 , filed mar . 5 , 1997 , which application is incorporated by reference herein . drain assembly 38 also preferably includes a setback portion comprising an elbow 44 that connects the top of height adjustable standpipe 42 to the drain outlet fixture of sink 12 , preferably using threaded slipnuts 46 . the use of elbow 44 between the drain outlet of sink 12 and height adjustable standpipe 42 helps to accommodate the legs of a handicapped person , using a wheelchair w , within the space of cabinet 16 beneath sink 12 . the outlet end of drain assembly 38 connects to a waste assembly which in turn communicates directly with a sewage disposal system . raising and lowering of countertop 14 , to which sink 12 is attached , is accomplished by the raising and lowering of support members to which countertop 14 is attached . these support members include support means which comprise right and left support brackets 48 , 50 , respectively , to which countertop 14 is attached . support brackets 48 , 50 each include an inner wall 52 , an outer wall 54 generally parallel to inner wall 52 , and an upper wall 56 extending between inner wall 52 and outer wall 54 . as shown in fig3 and 4 , outer walls 54 of support brackets 48 , 50 are attached to inner surfaces of right and left side drop panels , 28 , 30 , respectively , and upper wall 56 of support brackets 48 , 50 are attached to the bottom surface of countertop 14 . additionally , support brackets 48 , 50 are attached along rear flanges 58 , extending from inner walls 52 , to a lift plate 60 , as more clearly illustrated in fig7 . to raise and lower sink 12 and countertop 14 , and all attached components , adjustable attachment means are provided that include lift guide assemblies 62 . lift plate 60 is attached , as shown in fig7 to first and second lift guide assemblies 62 . each lift guide assembly 62 includes left and right lift guides 64 , 66 , respectively , fixedly attached to rear wall 26 , and a lift shaft 68 . lift shaft 68 is attached to lift plate 60 with screws 70 that pass through spacers 72 . screws 70 also pass through holes in rear flange 58 of support brackets 48 , 50 for retaining support brackets 48 , 50 to lift plate 60 . as also shown in fig7 raising and lowering of sink 12 is actuated by an electric motor assembly 74 , preferably a multimat motor model number 001 . 061 . 039 , manufactured by dewert motorized systems of frederick , md . height adjustment means are provided by electric motor assembly 74 which includes a screw drive member 76 that is attached to lift plate 60 through engagement with a lift bracket 78 that is fixedly thereto . electric motor assembly 74 is retained in position by right and left motor brackets 80 , 82 , respectively , that are fixedly attached to rear wall 26 . electric motor assembly 74 is actuated by a pendant switch 84 , attached thereto by cable 86 , for raising and lowering sink 12 . pendant switch 84 preferably includes up and down buttons , not shown , for controlling the direction of motion of sink 12 . electric motor assembly 74 is powered by electricity received through power cord 88 . referring to fig6 drain assembly is supported in position by plumbing support bracket 90 . plumbing support bracket 90 preferably is connected to left motor bracket 82 by screws ( not shown ), and includes a v - shaped portion 92 against which height adjustable standpipe 42 may bear for support during use of vanity 10 . as shown in fig9 and 10 , when a multiple compartment sink 94 is used with height adjustable vanity 10 , it is preferred to include a plumbing support bracket 96 therewith , which is attachable to lift plate 60 . to the end of plumbing lift bracket 96 is attached a plumbing capture bracket 98 , having an aperture through which passes a horizontal drain component 100 . as with plumbing support bracket 90 , plumbing lift bracket 96 provides added support for the drain assembly 38 during use of vanity 10 . fig1 illustrates use of a shampoo basin 110 with height adjustable standpipe 42 . here , height adjustable standpipe 42 is incorporated into a drain assembly 112 which is surrounded by a shroud 114 . a manually actuated lift assembly 116 , controlled by foot pedal 118 , is attached by bracket 120 to lift plate 122 , to which shampoo basin 110 is mounted . a suitable manually actuated lift assembly 116 is available from highland machine of highland , ill . lift plate 122 is preferably slidably attached to rear wall 124 as by lift guide assemblies 62 . in use , the height adjustable vanity 10 may be used in the fully raised position illustrated in fig1 and 5 , the fully lowered position illustrated in fig2 and 6 , or in any intermediate position . pendant switch 84 may be used to raise or lower vanity 10 to bring sink 12 and faucet f to an easily accessible position for a user of virtually any height or physical limitation . for wheelchair users , doors 18 may be opened to the sides to permit positioning of the front of wheelchair w and the legs of the user beneath countertop 14 . to raise the countertop 14 of vanity 10 , the appropriate button on pendant switch 84 is selected , thereby actuating electric motor assembly 74 , which in turn rotates screw drive member 76 . screw drive member 76 causes lift plate 60 to elevate , thereby raising all the components attached thereto , including countertop 14 and sink 12 . upward motion of lift plate 60 is guided by lift guide assemblies 62 . as countertop 14 is raised , roller shade 20 is extended from roller shade spool assembly 21 , maintaining a clean appearance on the front of vanity 10 . the steps of lowering countertop 14 of vanity 10 are initiated by selecting the alternate button on pendant switch 84 . screw drive member 76 rotates in the opposite direction when lowering countertop 14 , resulting in controlled downward movement thereof . as countertop 14 is lowered , roller shade 20 is rewound onto roller shade spool assembly 21 , helping to prevent fingers and hands from being pinched between countertop 14 and cross piece 19 . similarly , drop panels 28 , 30 also help fingers and hands from being pinched between countertop 14 and the upper edges of side walls 22 , 24 , respectively . when doors 18 are opened for positioning of wheelchair w beneath countertop 14 , they may be swung out to the side in a conventional manner , or , preferably , sildably positioned within vanity 10 as illustrated in fig2 . when positioned as illustrated in fig2 doors 18 are easily located in the space between inner wall 52 and outer wall 54 of right and left support brackets 48 , 50 , respectively . either method of positioning doors 18 may be accomplished using conventional cabinetry techniques already well known in the trade . while the preferred embodiments of the invention have been described , it should be understood that various changes , adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims .