Checking Inside the Building
Overview
Apartment buildings under Clause 57 (four to six storeys) and Clause 58 (apartment developments) have standards for the inside of each dwelling: room sizes, room depth, windows, ventilation, storage, private open space and accessibility. The Check measures them dwelling by dwelling from the rooms in a model you upload, and lists every dwelling in a dwelling schedule you can download.
The inside checks need rooms: from an uploaded model, or the units generated for apartment and mixed-use buildings drawn in the app (see Units in Drawn Buildings). Other buildings have none, so for them the Check says what it needs.
What the Model Needs
Upload an IFC model (Build → a site → Upload your design). The import reads:
| In the model | Used for |
|---|---|
| Rooms (IfcSpace) with a name or type: bedroom, living, kitchen, bathroom, laundry, storage, balcony ... | Room sizes, depth, storage volume, private open space |
| Apartments: rooms grouped into an IfcZone per apartment, or rooms numbered unit.room (1.01.03 is room 03 of apartment 1.01) | Which rooms make a dwelling |
| Windows (IfcWindow) in openings in the walls, with the walls marked external (IsExternal) | Windows in an external wall, room depth, cross ventilation |
| Space boundaries (which room a window serves) | Matching windows to rooms; without them the nearest room on that level is used |
When the import finds no rooms it says so. Rooms whose kind it can't tell from their name are listed, so you can rename them and upload again.
Exporting rooms
- Revit: place and bound every room, then File → Export → IFC. In the export setup, turn on space boundaries (1st or 2nd level). If you export from a 3D view, also turn on the option to export rooms in 3D views. Number rooms unit.room (1.01.03), or group each apartment's rooms into a zone.
- ArchiCAD: draw a Zone for every room. Zones export as IfcSpace. Number them unit.room, or group them per apartment.
- SketchUp: make each room a group and classify it as IfcSpace with the IFC classifier, then export IFC.
What's Measured
| Standard (57 / 58) | What the Check measures | From the clause |
|---|---|---|
| Room sizes (E3-6 / D26) | Each bedroom's width and depth (the largest bedroom is the main one), and the living room's width and area | Main bedroom 3 × 3.4 m, others 3 × 3 m. Living 3.3 m and 10 m² (studio and 1 bedroom), 3.6 m and 12 m² (2 or more). Clause 57 adds 0.8 m² for a wardrobe |
| Room depth (E3-7 / D27) | For rooms with windows on one wall only: depth from the window to the far wall, against the ceiling height | 2.5 × the ceiling height. An open-plan living, dining and kitchen room may be 9 m deep with a 2.7 m ceiling, if the kitchen is furthest from the window |
| Windows (E3-8 / D28) | Every habitable room (bedroom, living, kitchen, study) has a window in an external wall | |
| Cross ventilation (E3-9 / D29) | The share of dwellings with windows facing different ways 5 to 18 m apart | At least 40% of dwellings |
| Storage (E3-10 / D21) | The volume of storage rooms in each dwelling | Studio 8 m³ (5 inside), 1 bedroom 10 (6), 2 bedrooms 14 (9), 3 or more 18 (12) |
| Private open space (E3-4 / D20) | Each dwelling's balcony: area, depth and length, and (Clause 58) which way it faces | Table E3-4 by bedrooms. Table D8: facing north 8 m² and 1.7 m, facing south 8 m² and 1.2 m, otherwise by bedrooms |
| Accessibility (E3-11 / D18) | Not measured: doors, paths and bathroom layouts aren't in models | At least 50% of dwellings |
One finding per standard per building lists the dwellings that don't meet it, with why.
What it can't see
- Storage: robes and kitchen and bathroom cupboards count towards the standard, but only storage rooms are spaces in a model. A dwelling under the full volume shows Check: confirm the rest, such as a cage or locker.
- Room depth: for an open-plan room up to 9 m deep, whether the kitchen is furthest from the window. It shows Check.
- Cross ventilation: the breeze path is the straight distance between the windows, not the path through the rooms. It doesn't know which windows open.
- Private open space: access from a living room (there are no doors in the model).
The Dwelling Schedule
In the Check, Inside the dwellings lists every dwelling with its bedrooms, area and a mark per standard:
| Mark | Meaning |
|---|---|
| ✓ | Meets it |
| ✗ | Doesn't meet it |
| ? | The model can't confirm it |
| – | The model doesn't show it |
- Click a dwelling to pick it. Double-click it for its floor plan.
- Floor plans shows one storey at a time: failing rooms in red, the picked dwelling outlined, windows as dots, and the dwelling's issues beside the plan.
- Show rooms in 3D draws the rooms inside the model on the map, failing ones in red.
- CSV, Excel and PDF download the schedule: each dwelling's type, storey, area, private open space and the way it faces, storage, cross ventilation, a mark per standard, and the issues.
Sources
| What | Source | Licence |
|---|---|---|
| Clause 57 (Standards E3-4 to E3-11) and Clause 58 (Standards D18 to D29), with Tables E3-4, E3-6, E3-10, D8, D10, D11 and D12 | Victoria Planning Provisions, read 31 October 2026 | © State of Victoria |
| Rooms, zones, windows and space boundaries in IFC | buildingSMART IFC4 (IfcSpace, IfcZone, IfcRelSpaceBoundary) | © buildingSMART International |
| Reading IFC in the browser | web-ifc | MPL-2.0 |