Dimensions / Building materials / Toilets / Wall-hung toilet
A wall-hung toilet is a bowl hung on a steel carrier inside the wall, with the tank in the wall too; only the bowl and the flush plate show. The bowls project 17-3/8 to 26-5/8 in from the wall in Geberit’s compatibility table (Kohler’s Veil 21 in), against 26-3/8 to 31-11/16 in for floor-mounted toilets. The carrier needs a wall opening at least 3-3/16 in deep for Kohler’s 2x4 frame or 5-1/2 in for its 2x6 frame, is rated to 880 lb (400 kg), and sets the rim anywhere from 15 to 19 in on Geberit’s Duofix. The IPC allows a 30 × 56 in compartment for a wall-hung toilet, against 30 × 60 in for a floor-mounted one.
| Bowl projection | Carrier rating | Rim height (Geberit Duofix) |
|---|---|---|
| 17-3/8–26-5/8in | 880lb400 kg | 15–19in381–483 mm |
Sources: Geberit North America. Checked October 2026.
Kohler’s 2x6 carrier in a 5-1/2 in cavity, the room measured in the bathroom and Kohler Veil’s 6.0 / 3.0 L dual flush are filled in; change the carrier, what you measured, the code or the flush.
Rough-ins and carrier depths are the makers’ printed minimums; clearances are the model plumbing codes, which a local code may change.
The Kohler K-6284 carrier for 2x6 studs needs a wall cavity at least 5-1/2 in (140 mm) deep; yours is 5-1/2 in (140 mm). Like the others here it is rated to 880 lb (400 kg).
Kohler’s 2x6 carrier needs a wall opening 5-1/2 in deep, its 2x4 carrier 3-3/16 in.
IPC 405.3.1 asks for at least 15 in (381 mm) from the toilet’s centreline to a side wall or obstruction and 21 in (533 mm) clear in front of it; you have 15 in and 21 in.
A wall-hung bowl needs the same side and front room as a floor toilet: 15 in and 21 in under the IPC.
Canada’s plumbing code (2025) allows 4.8 L for a single flush and 6.0 / 4.1 L for a dual flush in homes. This toilet flushes 6 / 3 L.
Kohler’s Veil flushes 6.0 / 3.0 L, inside Canada’s 6.0 / 4.1 L for a dual flush.
Selling wall-hung toilets? Photograph the bowl from the side and its back with the fixing holes, mark projection, width, bowl height and the bolt centres in SizeMarker, and send the picture with your quote.
Mark a photoFrom Geberit North America’s compatibility table, which calls every figure approximate; Kohler’s own sheet gives the millimetres.
| Bowl | Projection | Width |
|---|---|---|
| Kohler Veil K-6299This page | 21 in (533 mm) | 15-1/8 in (384 mm) |
| Kohler Memoirs K-6918Square | 24-3/8 in | 17 in |
| TOTO AP CT426CFGElongated | 21-1/4 in | 15 in |
| TOTO RP Compact CT427CFGCompact | 19-1/4 in | 15 in |
| TOTO Neorest WX1Elongated | 26-5/8 in | 17-5/8 in |
| Duravit D-Neo 257709Elongated | 21-1/4 in | 14-5/8 in |
| Duravit ME by Starck 252909Round front | 17-3/8 in | 14-1/8 in |
| Laufen Pro 820968Round front | 20-7/8 in | 14-3/16 in |
| Villeroy & Boch Subway 5614Round front | 22 in | 14-5/8 in |
Sources: Geberit North America · Kohler
The carrier holds the bowl and the concealed tank; the wall has to be deep enough for it.
| Carrier | Figure |
|---|---|
| Kohler K-188292x4 studs | Wall opening at least 3-3/16 in (80 mm) deep and 50 in high; frame 46-1/4 in (1174 mm) high |
| Kohler K-62842x6 studs | Wall opening at least 5-1/2 in (140 mm) deep × 19 in (483 mm) wide × 50 in (1270 mm) high; frame 46-5/8 in (1185 mm) high |
| Geberit Duofix for 2x4Geberit North America drawing | Frame 3-1/8 in (80 mm) deep and 19-3/4 in (500 mm) wide |
| Geberit Duofix for 2x6Geberit North America drawing | Frame at least 4-3/4 in (120 mm) deep |
| TOTO DuoFitWT172M installation manual | System 45-21/32 to 50-5/16 in (1160–1278 mm) high for a rim of 15-11/32 to 20 in (390–508 mm) |
| LoadKohler; Geberit; TOTO | All three rate their carriers to 880 lb (400 kg) |
| CodeIPC 405.4.3 (New York draft text) | A wall-hung bowl hangs on a concealed metal carrier fixed to the structure, to ASME A112.6.1M or A112.6.2 |
| EuropeGeberit UK; EN 33 | Bowl fixing bolts 18 cm apart; Duofix frames 50 cm wide and 112 cm high, for bowls projecting up to 70 cm |
Sources: Kohler · Kohler · Geberit North America · TOTO · Kohler · New York Department of State · Geberit UK · Geberit UK
| Item | Figure |
|---|---|
| Tank in the wallKohler | Only the bowl and the flush plate show; Kohler’s Veil plate is 12-15/16 × 7-3/8 in (329 × 187 mm) |
| Height set at installationKohler K-6299; Geberit | The carrier sets it: Geberit Duofix from 15 to 19 in (381–483 mm); Geberit’s accessible layout puts it at 17 in within a 4 in range |
| Service through the plateKohler; Geberit | The flush plate comes off to reach the tank, the fill and flush valves and the supply stop |
| Shorter projectionGeberit table; floor-mounted sheets (our comparison) | 17-3/8 to 26-5/8 in from the wall, against 26-3/8 to 31-11/16 in long for floor-mounted toilets before the gap behind the tank |
| Smaller compartmentIPC 405.3.1; ADA 604.8.1.1 | IPC 30 × 56 in (762 × 1422 mm) against 30 × 60 in (762 × 1524 mm) floor-mounted; ADA wheelchair stall 60 in wide and 56 in deep against 59 in |
| Wall outletKohler | The waste leaves through the wall, so the floor under the bowl stays clear |
Sources: Kohler · Kohler · Geberit North America · Geberit North America · Geberit North America · Kohler · Sterling · TOTO · ICC · US Department of Justice
| Item | Figure |
|---|---|
| Side and frontIPC 405.3.1; UPC 402.5 in Washington | 15 in from the centreline to a side wall; 21 in in front under the IPC, 24 in under the UPC |
| ADA side distanceADA 604.2 | Centreline 16–18 in (405–455 mm) from the side wall |
| ADA seatADA 604.4 | 17–19 in (430–485 mm) to the top of the seat |
| Kohler Veil flushK-6303 | 1.6 / 0.8 gpf (6.0 / 3.0 L) |
| Canada, homesNPC 2025 | 4.8 L single; 6.0 / 4.1 L dual |
Sources: ICC · Washington State Legislature · US Department of Justice · Kohler · National Research Council Canada
17-3/8 to 26-5/8 in in Geberit’s compatibility table; Kohler’s Veil is 21 in (533 mm) and TOTO’s RP Compact 19-1/4 in. A floor-mounted toilet is 26-3/8 to 31-11/16 in long, plus the gap behind its tank.
Kohler’s 2x4 carrier needs an opening at least 3-3/16 in (80 mm) deep and its 2x6 carrier 5-1/2 in (140 mm); Geberit’s Duofix is 3-1/8 in deep for 2x4 and at least 4-3/4 in (120 mm) for 2x6.
Kohler, Geberit and TOTO rate their carriers to 880 lb (400 kg). The IPC wants the carrier fixed to the building structure, so the strain does not reach the pipe connection.
Whatever the installer sets: Geberit’s Duofix takes the rim from 15 to 19 in, TOTO’s DuoFit from 15-11/32 to 20 in. ADA wants 17–19 in to the top of the seat.
Some: the IPC allows a 30 × 56 in compartment for it against 30 × 60 in for a floor-mounted toilet, and ADA a 56 in deep wheelchair stall against 59 in. The carrier needs a 2x6 wall, or a 2x4 carrier.
Through the flush plate: it comes off, and the valves and the supply stop are reached through the opening behind it (Kohler, Geberit).
A buyer of wall-hung bowls asks which carriers the bowl fits and its fixing-bolt centres (18 cm in Europe), the projection, width and bowl height, the outlet and inlet positions, the flush volume of the matching tank, and the carton size and weight. Mark those on a photo of your own bowl and its back with SizeMarker, like the picture at the top, and share one card in WhatsApp or WeChat.
