Add a storey

A storey is one level of the building. It has an elevation, a height and its own elements. To make a building with two floors, add a second storey at the height where the first one ends.

Before you start

You have a session from Start a building. The ground storey is 3 metres high.

Write the storey

The new storey starts at 3 metres. It has its own walls and its own floor slab.

import type { BmStorey, BuildingSession } from '@opengeometry/floorkit';

export const firstFloor: BmStorey = {
  id: 'first',
  name: 'First floor',
  elevation: 3,
  height: 3,
  walls: [
    {
      id: 'first-walls',
      points: [
        [0, 0],
        [6, 0],
        [6, 4],
        [0, 4],
      ],
      closed: true,
      thickness: 0.2,
    },
  ],
  slabs: [
    {
      id: 'first-floor-slab',
      profile: {
        outerRing: [
          [-0.1, -0.1],
          [6.1, -0.1],
          [6.1, 4.1],
          [-0.1, 4.1],
        ],
      },
      thickness: 0.2,
      baseOffset: -0.2,
    },
  ],
};

Add it to the building

export function addStorey(session: BuildingSession): void {
  session.apply(
    { kind: 'add-storey', buildingId: 'building', storey: firstFloor },
    session.revision,
  );
}

The add-storey command adds the storey with its elements, and the session builds it. You keep the session and its undo history. The command rejects a storey id that the building has. replace-storey-settings sets the name, the elevation, the height and the usage of a storey, and remove-storey removes a storey. See Editing and history.

Rules

elevation is the height of the storey floor in the world. It is the only world height in a storey.
The elements in a storey use offsets from that elevation. You do not add the elevation to them.
Each storey has its own walls. Walls on different storeys do not join.
Ids are unique in the full model, not only in one storey.

Use the storey in commands

Each edit command names its storey. To add a door to the new walls, use storeyId: 'first' and wallId: 'first-walls'.

Move and reshape

Change the elements that you made.

Create a plan view

Make a plan of one storey.

Last modified on October 11, 2026

Documentation

Before you start

Write the storey

Add it to the building

Rules

Use the storey in commands

Next

Move and reshape

Create a plan view

​Before you start

​Write the storey

​Add it to the building

​Rules

​Use the storey in commands

​Next

Move and reshape

Create a plan view

Before you start

Write the storey

Add it to the building

Rules

Use the storey in commands

Next