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Key figures: BRI, GRZ, GFZ, Vollgeschosse and A/V

The project overview shows a building's key figures beside the current stage, worked out from the models as they are now, like the areas: BRI, GRZ and GFZ against the plot, which storeys may count as Vollgeschosse, and A/V. They are hints for the design, not a check of what is permitted: the Bebauungsplan and the authority decide.

What each figure is

  • BRI (Brutto-Rauminhalt, DIN 277): the volume within the outer faces of the walls, from the underside of the lowest floor slab. Where a pitched roof stands, up to the top of its faces, dormers included; overhangs don't count.
  • GRZ (BauNVO § 19): the area the building covers in plan, over the plot area.
  • GFZ (BauNVO § 20): the gross floor area (BGF) of the storeys that may be Vollgeschosse, over the plot area.
  • Vollgeschosse: a storey counts if enough of its floor has the clear height its state asks for, and the top of its ceiling lies high enough above the ground. Each Landesbauordnung has its own rule.
  • A/V: the outer envelope (walls, lowest floor, roofs at their slope) over BRI. The lower, the more compact the building.

What they need

  1. Walls drawn on the storeys of the building: the figures come from their outer faces, on every layer, hidden ones too.
  2. A storey height for each storey in the project settings; a storey without one is taken as 2.75 m, and the card says so.
  3. The plot area: take the parcel over from the official register under Official land register in the settings, or enter the Official area. Without it, a plot outline drawn from the register stands in, and GRZ and GFZ say so.
  4. The State (Land) of the site: it is set when a parcel is taken over from the register, or chosen in the site settings. Without it, no storey is judged.
  5. For storeys in the ground, the building's terrain height in the settings: the ground the Vollgeschoss rule measures from.

In a release

  1. When a stage is closed, the gate dialog shows BRI per model and GRZ and GFZ per site, and the release keeps them, with the plot area and state they were worked out against.
  2. Under Since release on the overview, BRI is compared with the model now, and a variant of a decision shows its BRI beside its main branch.