Identify the complete system
A brand is not a complete specification. A cooling or heat-pump system has an outdoor model and an indoor coil or fan-coil model; a dual-fuel system also retains or replaces a furnace and adds controls for two heat sources. The AHRI reference number identifies the certified indoor/outdoor combination and its rated performance.
Trace the work around the boxes
Read the scope from the outdoor location to the rooms served. Look for the equipment base or stand, refrigerant route, electrical disconnect and circuit work, drain, venting, sheet-metal transitions, filter arrangement, thermostat, removal, permits, and startup. The applicable list depends on the house; the point is to make included work visible.
Separate fixed scope from unresolved conditions
Allowances, exclusions, and unresolved conditions should sit outside the fixed scope. Access limitations can be confirmed from the route; electrical capacity from the panel and load review; duct changes from inspection and measurements. A proposal is easier to compare when it states which condition remains open and what evidence will resolve it.
Put administrative work in writing
Confirm who obtains permits, registers equipment, submits rebate documents, and supplies the final paperwork. If a discount is expected, ask whether it is included in the quoted total, deducted later, or paid separately by a program administrator.