It is reasonable to expect a contractor to replace the last foot of HVAC duct work, the connection between the insulated duct and the register?

Question

The contract was to replace an antiquated HVAC and duct work. Since the registers are a standard size, would this connection also be a standard pre-fabricated part? What is that last connection called?

Answer 1

I believe it's called a "boot", and yes, they're generally pre-fabricated.

However, if the existing ones are in good shape, they shouldn't need replacing. If they're damaged, then the reasonableness depends on what your contract says.