Air terminal

Air terminal places the points the air comes in and goes out through. The list beside the tools offers the kinds your template provides; in a project under the UK template, for example, kitchen, bathroom, WC and utility room extract valves, living room and bedroom supply valves, a trickle vent, an intermittent extract fan, a cooker hood, wall-mounted split unit connection points, a ceiling cassette connection point, a cooled-air supply grille and a return-air grille.

Each kind says where it goes. Valves and grilles stand on a ceiling or high on a wall, depending on where you click; a trickle vent, a fan, a cooker hood and a wall-mounted split unit stand on a wall; a cassette stands on a ceiling. The ducts follow by themselves: with mechanical extract ventilation every extract is ducted to the ventilation unit, and with MVHR every supply is too, each terminal by its own duct up into its ceiling, across it to a shaft and up to the unit. Each indoor unit of the air conditioning is served by the nearest outdoor unit, with its own refrigerant pipe pair and its condensate. None of it is stored: move a point and its duct or pipework is laid again. It all shows with the Mechanical overlay and on the ceiling plan.

• Placing the extracts of the kitchen, the bathrooms and the utility room, and the supplies of the living spaces.
• Adding a cooker hood or an extract fan on a wall.
• Placing the indoor units of a split air conditioning system.

One new device entry at the end of the project's list of devices, as one step that one undo takes back: its kind, and either its wall, its distance along it and its face, or its room and its point, with the phase the view draws in. The ducts, the pipework, the shafts, the airflows and the fittings are never written: they are worked out each time the project is built.