Screening Tool: Insurance Estimates

[Max Householder]

I know the correct answer is, "It depends on the property, call a local insurance estate agent!"

That said, for quickly screening multiple properties, I'm interested in getting a sense of how the scale works for insuring investment properties.

I'm looking at properties near my own home, so I know what it costs to insure a 1,000 sqft single family home here: roughly $800/year. I've seen many rules-of-thumb for estimating insurance on a duplex and most say bet on roughly $100-150/month ($1200-1800/year). This makes sense to me since a duplex around here is roughly 2x the sqft of my home and when you factor in 2x the occupants you'd figure insurance should be ~2x as much.

Now, when I look at a 4-family quad, am I doubling the duplex number? This seems really high and I would think it's not consistent as you go up, i.e. insurance on a 50-unit building won't be 50x the cost of a single-family home, but maybe it is? I feel like a quad should be more than a duplex, but not 2x as much. On the flip side I think just estimating $1200/year for every SFR, Duplex, or Quad I screen doesn't make sense either. Is it better to do an estimate per sqft?

What do you guys use for an estimate on insurance costs when screening properties?