How do you quote scan-to-BIM before you've seen the site?

Quoting modelling from a scan before a site visit is one of the hardest parts of the job. Too high and you lose the bid, too low and you lose money.

How do you do it?

• Per square foot or metre, per element, per hour, or per project?
• What do you ask the client for first: drawings, photos, a sample scan, LOD per discipline?
• How do you handle plant rooms and dense MEP, which can take several times longer than the rest of the building?

Ranges and rules of thumb are more useful than exact numbers.