Guidelines for HVAC planning

The toilet seat

  • In Gaius bathrooms, a high toilet seat (seat height of 460 mm without the lid) or a model with a hard lid (seat height 480 mm) is recommended because it is sturdier and also because it often makes sitting down and getting up easier for people with disabilities.
  • To facilitate cleaning and providing assistance, floor-mounted toilet seats should be located 130–150 mm from the back wall.
  • The water pipe for a floor-mounted toilet seat should run from the other side of the basin unit so as to ensure that enough leg room is left for an assistant behind the toilet seat on the basin side.

The floor and floor drains

  • A floor that slopes slightly, the use of a doorway drain instead of a threshold, and a side drain located by the back wall make using auxiliary equipment easier.
  • If a round floor drain is used, it must be equipped with a wheelchair-proof RST lid and be located underneath the shower seat, close to the wall. If another drain is needed and it is located under the basin, the drainpipe from the basin should run beneath the floor, with a side connection. It should never run directly into the floor drain, as this impedes the movement of wheelchair users.

The washbasin

  • A height-adjustable basin unit with adjustable drainpipes and water pipes is recommended. The drainpipes should always be located as close to the back wall as possible to ensure that they do not impede the movement of wheelchair users.
  • A tap with a single looped lever and without pop-up waste is recommended as the tap for the basin unit. The spout of the tap should be sufficiently long to reach the deep part of the basin. A looped lever is easier to grip even with rheumatic fingers.


  • For safety and hygiene reasons, the piping should always be concealed. If surface mounting is settled on during renovations, the water pipes and flanges must be chrome-plated and the pipes must run near the floor rather than the ceiling, to ensure they are not accidentally used for support.

The shower, support rails, and taps

  • The shower rail provided with the shower kit should not be installed; separate sturdy support rails should be used instead.
  • For the shower tap, a single-lever model with a short spout and press-operated user-friendly shower switch is recommended. A single-lever tap can be used while sitting on either the shower or toilet seat, even if the user only has one functioning hand. It is also easier for an assistant to use the tap with either hand, while the other hand is left free to support the user.

General guidelines

  • A height-adjustable basin unit should always be equipped with an adjustable drainpipe and the water connection with flexible connection hoses. A telescope pipe should be used for floor joints, and a bellows-type connection pipe for wall joints.
  • If the basin is installed at a different height than the one recommended, this must be taken into consideration in the placement and design of the water and drain connections, as well as in the planning of the location and implementation of the foundation.
  • The recommended installation distance for wall joints is 100 mm (c/c), and the tap elbows should be located near the mixer so as to avoid unnecessary extension of connection pipes.
  • The wall drainage for basins with fixed-height installation can be realised with a horizontal connection pipe directly from the water trap to the wall joint. However, the installation must be carried out very precisely, as the installation tolerance for the recommended location using the standard water trap elements is max. +/–3 cm both horizontally and vertically.
  • For basins equipped with a lifting device, a bellows-type pipe should be used for the drainage connection in both types of installation.