Post by Franz Warm in The Haunted House Map Pack comments

Ground and 2nd Floor: &nbsp;32x22 units (2240x1540).
Cellar: &nbsp;28x36 units (1960x2520).

Viewing post in The Haunted House Map Pack comments

I've only tested in roll20... With a unit size of 70 pixels, these are recommended dimensions:

Those settings worked great in The Foundry, thank you, sir!