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Is this a habitable room, and what does OIB guideline 3 then require?

Piloti classifies the room by its use, not by the label in the drawing, and then checks room height, daylight and ventilation against OIB guideline 3, with a citation and a daylight sketch.

In short

Piloti classifies a room as a habitable room (Aufenthaltsraum) with a citation, by the definition and its actual use rather than its name in the drawing, then takes the requirements of OIB guideline 3 for room height, daylight and ventilation from the clause and checks your dimensions against them.

Try it with a real questionChecked: September 2026

What Piloti delivers

The classification with a citation
Habitable room yes, no or open, with the provision and the fact the classification rests on.
A check table
Room height, daylight and ventilation side by side, one row per requirement, or per room when a whole flat is checked.
A daylight sketch
Where daylight is the question, Piloti draws the incidence of light with the glazed share of the window.
The passage in its wording
The sentence of the guideline the answer hangs on stands as a quote in the answer, clickable through to the source.

Why the classification comes first

OIB guideline 3 ties its requirements for room height, daylight and ventilation to whether a room is a habitable room. That is a legal classification. “Hobby room” in the drawing does not decide it; the use does. A basement room where people regularly work can be one; a generous storeroom is not.

Then come the dimensions, and two typical mistakes hang on them. The storey height is not the clear room height. And daylight cut off by a building opposite does not prohibit the window: it changes the required window area. Turn “cut off” into “not met” and you have skipped the provision.

Here too, existing buildings, extensions and major renovations often trigger different requirements than new build, and the state’s edition binds as well.

How Piloti works through the question

  1. 01

    Classify the room

    Piloti fetches the provision that defines a habitable room and applies it to the use from your question or the project documents. If the use is unclear, a question comes, not a silent yes.

  2. 02

    Read new build or existing

    If the project records whether it is new build or existing, Piloti works under that before citing a new-build clause.

  3. 03

    Fetch the requirement

    Room height, daylight, ventilation, window area: the limit comes from the clause, cited to the clause and checked against the source text before it is shown.

  4. 04

    Assign the dimension

    The dimension comes from the question, the drawing or the documents, and its origin is in the sentence. Requirement first, then dimension, never the other way round, or the wrong thing gets checked carefully.

What Piloti needs from you

  • What the room is used for, not just what the drawing calls it.
  • The clear room height, not the storey height.
  • Room area, window size and glazed share, and what lies opposite the window.
  • The state, and whether it is new build or existing.

Good to know

Piloti checks dimensions against clauses; daylight simulation and ventilation design stay with the specialists, and if a dimension is missing, Piloti asks for it. For workrooms in businesses, Piloti also draws on the Arbeitsstättenverordnung and keeps the two sets of rules apart. A borderline case, such as a workplace in a semi-basement, goes into the pre-application meeting with the reasoning in hand.

Questions

What is a habitable room?

A room intended for people to stay in for longer periods, such as a living room, bedroom or workroom. The governing provision is in the OIB guidelines or state law, and details can differ from state to state. What decides is the use, not the name in the drawing.

Is a basement room a habitable room?

If people use it for longer periods, it can be one, and then the requirements for room height, daylight and ventilation apply. Whether a basement room can meet them often depends on daylight. Piloti classifies the room by its use and says which fact the classification rests on.

What room height does a habitable room need?

The minimum height is in OIB guideline 3 in the edition your state has declared. It means the clear room height, not the storey height. Piloti cites the value with its source and checks your dimension against it.

May I plan a window if the neighbouring building cuts off the daylight?

Cut-off daylight does not prohibit the window. It changes how large the window area must be. Piloti shows the incidence of light as a sketch and cites the clause that sets the area.

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