Preparing your IFC file

Main building model

Include only elements that define the building envelope and room geometry. Exclude everything else to keep the file lightweight.

Include:

IFC type	Description
IfcSpace	Room volumes — required for room detection
IfcWall / IfcWallStandardCase	Walls
IfcWindow	Windows
IfcSlab	Floor and roof slabs
IfcRoof	Roof elements
IfcPlate	Balcony slabs, overhangs, horizontal elements

Exclude: furniture, MEP/HVAC, stairs, railings, annotations, and detailed interior fittings. If it does not affect room shape or how much sky a window can see, leave it out.

Context buildings (optional)

Surrounding buildings should be modeled as masses (generic volumetry) rather than detailed BIM models. This keeps file sizes small and ensures the sky obstruction calculation stays accurate.

Recommended file sizes

Model type	Max recommended size
Main building IFC	< 10 MB
Surrounding buildings IFC	< 2 MB each

Keeping files within these limits ensures the tool runs smoothly in the browser. For larger or more complex models, contact upskiller about the advanced LUX Live Revit plugin.