From a building page, scroll to the Attachments section below the Spaces section.

If there are attachments, the link to add more will be above the other attachments and will say ‘Add an Attachment’. If there are no attachments yet, the link will be in the empty Attachments section’s card.

Clicking either link will open your OS file picker. Select the file you want to attach from your computer.

A new row will be added to the Attachments section, with a loading indicator showing where the thumbnail will be while it’s loading.

Once the attachment uploads, it will display as either a thumbnail (PDF, JPG, etc) or icon (CSV, XLS, etc) along with the name of the file on the left and the file type and icon button to download on the right.