Extensions¶
A building doesn't have to consist of a single body. On the free floor plan you add as many extensions next to the main building as you like — each with its own height and its own upper end. You create them in the Floor plan step; you set their top end in the Roof step.
What an extension is¶
An extension is a self-contained secondary body next to the main building — not a projection of the main building, but a body of its own with walls of its own.
- An extension always has just one floor. Only the main building gets the floors from the Floors step.
- Every extension has its own eaves height. It doesn't depend on the ceiling heights of the main building.
- Main building and extensions share one base plate. Wall heights and roofs are created independently of it.
- Extensions exist only with the floor-plan shape Free — not with rectangle, L, T and U.
Creating extensions¶
Extensions are created in the Floor plan step, when you apply your drawing:
- Draw all outlines in the drawing editor — main building and extensions together.
- Click "Apply floor plan".
- Click the main area first, then the extension areas one after another.
- "Done" completes the assignment.
An extension has to adjoin the main building — or an extension you have already assigned before. An area that doesn't connect anywhere can't be applied as an extension.
Every extension gets a fixed color. It is the same in the drawing area, in the "Extensions" panel and in the 3D preview, so it's always clear which body is meant.
Height, Active and Passage¶
The assigned extensions are listed on the right in the collapsible "Extensions" block — one row per extension with a colored dot, name, value and slider.
| Setting | Range |
|---|---|
| Height (eaves height above the base plate) | 0,30 m to 10,00 m |
| Step size | 0,10 m |
| Starting value of a new extension | 2,00 m |
In addition there are two switches per extension:
- Active — off: the extension is not built. All its settings are kept, and you can switch it back on at any time.
- Passage — opens the dividing wall to the main building over the clear inside width of the extension, so that the two rooms flow into each other.
Dividing wall to the main building¶
Main building and extension share an exterior wall as the dividing wall.
- The dividing wall always belongs to the main building — for an extension that hangs on another extension, to the extension before it.
- If the extension is taller, it sits on the same wall flush at the top. The wall doesn't step there.
- Between the two interiors there is therefore one wall of 0,40 m — not twice 0,40 m.
Extensions and upper floors¶
If you draw an upper floor, those areas of the extensions that reach past the underside of that floor are locked. They lie hatched in the plan and can't be applied as an area there.
What is locked is the applying, not the drawing
Over a locked zone you may keep drawing — guide lines stay allowed. Only the area itself can't be applied there.
The upper end¶
You set what happens on top of an extension in the Roof step. There you first pick the body — Main building, Extension 1, Extension 2 … — and then one of three options:
| Choice | What the extension gets |
|---|---|
| Roof of its own | A roof just for this extension. You then pick the roof shape; that includes "No roof" — the extension then ends flat at eaves height and stays open at the top. With a gable or shed roof you click the ridge reference edges on the outline of the extension. |
| Roof terrace | A flat roof with a railing on the exposed edges. Edges against a taller wall don't get one. |
| Extend the roof of the main building | No roof of its own: the main roof is built over the main building and the extension, and the walls of the extension run up to underneath it. |
Choose the ridge reference edges again after extending
With "Extend the roof of the main building" the outline of the main roof changes. You have to choose the ridge reference edges of the main roof again afterwards — see Roof.
Minimum distance between the roofs¶
The roof surfaces of extension and main building must not touch: at the narrowest point 15 cm of distance must remain, roof overhang included. If the distance falls below that, the app reports it and doesn't build.
That also applies where two roofs meet at the shared dividing wall. There both roof slabs end at the same vertical plane, so the distance is zero — no matter how tall you make the extension.
A main building with a flat roof carries no extension with a roof of its own
Because the distance at the dividing wall always stays zero, no extension with a roof of its own can be built next to a flat roof. What's left for that extension is "No roof" and "Extend the roof of the main building".