BIM Explorer - free
Pick a storey and BIM Explorer draws its plan from the IFC model: what's cut at the height you choose drawn heavy, what lies below drawn light, with a scale bar and a north arrow. Zoom and pan round it on screen - free. BIM Explorer Pro saves every storey to scale as a vector PDF.

Open the .ifc file, or click Load sample and pick the sample house, a duplex apartment or a clinic. The sample house is on the downloads page too. Floor plans cover the models that are showing.
In the Views tab choose Open floor plans, or type floor plans in the command palette. The plan opens on the storey nearest the ground.
Choose another storey from the list, and change Cut height above the floor - 1.2 m is the usual plan cut, through doors and windows. "Drawing…" shows while a big storey is worked out.
Scroll to zoom, drag to pan, and double-click to fit the whole storey again. The scale bar changes as you zoom.
Export PDF opens the storey plans dialog: pick the storeys, the cut height and A3 or A4, and every storey is drawn to a standard scale as a vector PDF, one page each. Part of BIM Explorer Pro.
Help: Floor plans has every option in detail.
Free in BIM Explorer. No time limit, no account, no ads, and your models never leave your PC. BIM Explorer Pro is there when you need takeoff, a BOQ, IDS and clash checks.
Yes. Floor plans on screen are part of the free BIM Explorer. Saving plans to scale as a PDF is part of BIM Explorer Pro (a one-off £29.99).
BIM Explorer slices the model's own 3D geometry at the cut height - it doesn't need 2D drawings in the IFC. Elements cut by the plane are drawn heavy and the edges of what lies below are drawn light.
Not yet. Use the 3D view and the model tree to find and select elements.
A storey of a large model can take a few seconds. Plans are kept once drawn, so going back to a storey is instant.

Green has quantities, amber has none - see if a model can be priced before you start.

Lengths, areas and volumes by type or storey, sent to a BOQ that stays linked to the model.

Five ready-made checks - Uniclass, spaces, base quantities, common properties and a handover minimum.

Issues that keep the camera, the section plane and a snapshot - BCF 2.1 and 3.0, free.

The model tree, every property, display modes, sections and measuring - free and offline.

Colour by IFC class, storey, material or any property, with a legend to hide, isolate and select.

Hard clashes between models or IFC classes, exported as BCF - and what changed between issues.
The IFC viewer is free. BIM Explorer Pro is a one-off £29.99, with a free 7-day trial.