How Does Maintenance Determined in a NY Co-op

[Noam Ofan]

My wife and I live in a co-op we've owned for 10 years now in Brooklyn, NY.

We recently discovered that our maintenance bill is almost the same as bigger apartments in our building.

We live in a large studio and pay about $1130 a month. Our apt is about 850 sq ft.

We saw a 1BR apt in our apt that is 950 sq ft and their monthly maintenance is $1180

That sounds weird to us, but we have no idea how to challenge this bill.

What is the best way to check if our bill is too high?

Is it possible to get reimbursed for years back in case the building got our bill wrong?

Thank you.