How are room schedules and area calculations done in Revit?
Room and area objects
Revit has two tools for area calculation. Room objects carry each space's name, number, use and net area; when a wall moves, the area updates itself. Area plans allow separate boundaries to be drawn according to different measurement rules, such as gross area, floor-area-ratio area or unit area. In this way both the interior room list and the zoning calculation come from the same model.
Which area is calculated how?
| Area type | In Revit | Used for |
|---|---|---|
| Net room area | Room object, to the inner face of walls | Room schedules, interior design, finish schedules |
| Gross area | Area plan, to the outer face of external walls | Construction area, cost, permit |
| Floor area ratio area | Separate area plan with included/excluded areas per regulations | Zoning checks |
| Unit area | Area plan per apartment, shop or office | Sales, condominium records, entitlements |
We explain these concepts in detail in our articles on gross vs net area and floor area ratio and site coverage.
Room finish schedules
When floor, wall and ceiling finishes are entered for each room, Revit turns them into a room finish schedule. Wet rooms, plant rooms and common areas are listed separately, and finish quantities come from the same data. When the design changes, the schedule is not corrected by hand; it updates with the model.
Contribution to engineering calculations
- Mechanical: room area, volume and use feed heat loss and gain and fresh-air calculations.
- Electrical: room use determines lighting levels and socket requirements.
- Fire: occupant load and escape distances are checked against room areas.
In urban renewal projects the unit areas allocated to existing owners are critical, so taking these tables from the model reduces the risk of error; we cover the process in our article on the urban renewal design process.