Describe the household before dividing the floors
A label such as upstairs bedrooms and downstairs living is a useful starting sketch, but it can miss the room that matters most. A study upstairs may be occupied throughout the day. A downstairs bedroom may need quiet operation while the rest of the family uses the kitchen. Write a short weekday and weekend occupancy description before discussing zones. The installer can then assess the actual combinations rather than assume each floor behaves as one room.
For a two-storey home in Alfredton, Lucas or elsewhere around Ballarat, include any rooms that were added or repurposed after construction. A converted sitting room or enclosed retreat can change the brief without changing the total floor area very much. Mark whether doors are normally open or closed and where you spend the evening. These observations do not size equipment, but they give a designer information that an area-only estimate cannot capture. Ask for those intended operating combinations to appear in the proposal.
Ask for a room-by-room design explanation
The floor plans should show which rooms are served, where outlets are proposed and what assumptions have been made about the building. Ask how the installer has allowed for different glazing, room orientation, insulation and exposure on each floor. A bedroom under the roof and a sheltered downstairs room need not present the same design problem. Do not accept a uniform outlet count as a substitute for explaining room requirements.
The Australian Government's Your Home heating and cooling guidance distinguishes whole-house and room-based systems and stresses matching the system to the home. For your quote, turn that principle into a concrete request: identify the rooms, expected use and building assumptions used in selection. If future insulation or glazing work is assumed, record whether it must be completed before the system is commissioned. An estimate for an improved building should not quietly be treated as a promise for the building as it stands.
Trace the vertical route, not just the ceiling outlets
A two-storey drawing can make ducts look simple because the route between floors is hidden. Ask where supply and return ducts cross that boundary. Does the proposed route use a cupboard, a service shaft, a bulkhead or an accessible ceiling void? Have the designer show its effect on usable space and finishes. A duct route drawn through a wall does not establish that the wall can accommodate it.
In an existing home, ask which areas can be inspected before the quote is finalised. Finished ceilings and restricted voids may leave uncertainties that need a building contractor's input. Make the method for resolving those uncertainties explicit. Avoid a scope that promises ducting to every room while leaving all access and reinstatement work unspecified. The limited roof-space guide provides related questions, but a two-storey job also needs to account for the concealed route between occupied levels, not only the roof above the upper floor.
Review the return path on both levels
Ask how air from the rooms on each floor returns to the equipment in the proposed layout. The answer should include the normal door positions, particularly for bedrooms. A return grille on a plan is only part of that explanation. If an installer expects doors to remain open, that needs to be compatible with privacy, sleep and the way your household uses the rooms. Ask for the design to address the intended conditions rather than simply demonstrate with all doors open.
Do not try to solve a return-path concern by cutting door gaps or adding grilles yourself. Those changes need consideration of the building and the system as a whole. Ask what alternatives the designer recommends and whether any builder's work is included. If a new return grille occupies a landing wall or cupboard, check it against storage and furniture plans. A route that works on an empty floor plan can become inconvenient once a bookcase or linen cabinet occupies the same space.
Choose zones by operating combinations
An upstairs/downstairs split may be a useful arrangement, but ask whether it matches the smallest area you genuinely expect to run alone. A system serving a whole house should not be assumed to behave well when only a small study is selected. The installer needs to assess the selected equipment, duct arrangement and zone controls together. Ask for the permitted combinations and any areas that must remain open to be explained at handover.
The manufacturer's explanation of ducted zoning describes dampers controlling airflow through ducts. That is different from installing an independent heating and cooling machine in every room. Ask whether each zone merely switches airflow or also uses a temperature sensor, and what happens when different rooms want different conditions. The existing zoning guide covers the general concept; this decision is about proving that the floor-by-floor arrangement fits your household's actual use.
Compare one ducted system with more independent arrangements
A single system may suit a home where most rooms are used together and the routing works well. More independent equipment may deserve investigation where one floor is used very differently, where access makes a common network awkward or where occupants need greater separation. Request a comparison using the same room and comfort brief. Comparing a whole-house proposal with one that only conditions selected rooms gives a misleading impression of value.
Ask each designer what happens if one part of the arrangement is unavailable for servicing. Also discuss the number and location of outdoor units, controllers and filters you would manage. More independence can introduce more equipment and different maintenance tasks. A single central installation can simplify some of those tasks while tying more rooms to the same plant. These are practical differences to weigh alongside installation work. There is no responsible answer based only on the fact that the house has stairs.
Position controls where their role is understood
Ask where each temperature reading comes from and how that reading affects operation. A wall controller on a landing may be convenient to reach, but convenience alone does not establish that its sensor should govern all occupied rooms. The installer should explain which sensors are active, what the displayed temperatures represent and whether the arrangement can be adjusted within the manufacturer's supported options. Keep that explanation with the user instructions.
Describe the moments when comfort matters: bedtime, an upstairs workday or breakfast downstairs before other rooms are occupied. Ask the installer to walk through how the controls will handle each case. This is more revealing than a demonstration of the app's home screen. If you are changing controls on an existing system, read the controller replacement guide. A new interface may improve usability, but it cannot by itself prove that an existing duct or return-air arrangement suits the house.
Decide how installation affects finished rooms
Ask which ceilings, walls or cupboards will be opened and who restores them. A quote can include running ducts without including plaster repairs, repainting or joinery changes. Mark the work on both floor plans and identify any rooms that must be cleared. If the home remains occupied, discuss access through stairs and hallways, protection of finishes and how the equipment reaches its final position. Do not infer a job duration from a single-storey example.
For a period home or a house with later additions, separate the original structure from the extension on the drawing. Ask who confirms routes through concealed construction before work starts. If the design depends on a bulkhead, request its appearance and dimensions on the building drawings before approval. A small equipment decision can otherwise become a much more visible interior alteration than expected. Coordinate that choice with the person responsible for the building work rather than leaving two trades to make different assumptions.
Test the combinations that drove the design
At handover, ask to see the agreed floor and room combinations demonstrated. Confirm that the labels correspond to the correct areas and that the installer explains any restrictions on operating individual zones. Use the household's normal door positions where the design allows. Record what was tested, what could not be meaningfully demonstrated in the weather that day and how any later concerns should be raised. Do not treat a single controller temperature as proof of every room's comfort.
Walk through ordinary operations yourself while the installer is present: select the evening arrangement, change the schedule, return to normal settings and identify the filter access points. Ask what remains usable if internet access fails where an app is included. Keep the floor plans and zone names consistent with the labels the family will actually recognise. Clear instructions can prevent later confusion between a control setting problem and a room that needs the installer to review its airflow or design.
Read the proposal against the entire house
Before deciding, place the quote beside the plans and check every occupied room. Look for omitted spaces, assumed door positions, unspecified vertical routes and making-good exclusions. Confirm where the indoor equipment can be serviced and how it could eventually be replaced. Ask whether access panels remain reachable once wardrobes and shelving are fitted. These are reasonable questions before signing, while the design can still change without disturbing finished work.
The refrigerated ducted service page introduces the equipment options, and the outdoor-unit location guide covers the external part of the layout. If the second storey is a new addition, use the extension guide to coordinate old and new work. Send plans with room names and a short account of how each floor is occupied. That gives an installer a useful basis for a site assessment without turning a preliminary enquiry into an unsupported promise of system performance.