Start with a service map and a responsibility map
Draw the main house and proposed granny flat together, then ask the relevant trades to identify existing service entry points and proposed routes. Mark the meter, switchboard, communications equipment and known water and drainage features. Label uncertain locations as uncertain. An old plan may be useful background without proving what is currently underground or inside a renovated house. The homeowner's first task is to gather records and explain how the property is used; the designer and licensed trades need to establish the technical solution.
Alongside the physical map, write down who will arrange each part of the work. A builder, plumber, electrician, retailer, network operator and communications provider may have different responsibilities. “Services included” does not tell you which applications, investigations, connection work or equipment are covered. Ask for each boundary to be described in ordinary language. That makes it easier to compare quotations and prevents a late discovery that one contractor assumed another would arrange the final connection. Keep the maps together because changing a route may change who needs to approve or perform work.
Establish water and sewer requirements with Icon Water
A nearby water tap does not settle the permanent supply arrangement for another dwelling, and an existing drain does not prove a suitable sewer connection. Ask the plumber and designer to review the proposed fixtures, existing infrastructure and the information needed for the project. Icon Water's project applications and compliance guidance explicitly includes secondary residences. Use that process to confirm the project's requirements rather than relying on a generic granny-flat package or a connection detail from a different authority area.
Ask which parts of the proposal depend on an inspection or further information. The position and condition of existing private services can affect the final route, so keep the uncertainty visible before committing to a finished landscape. If the kitchen or bathroom moves during design, request a review of the service proposal rather than assuming the earlier allowance still applies. The useful outcome is a documented arrangement showing what will be connected, where, by whom and what evidence is required before the building can be used.
Keep maintenance access in the finished plan
Service access should survive the landscaping and fencing stage. Ask the trades to mark items that need to remain reachable and explain the access required for inspection, isolation, repair or replacement. Then compare those locations with paths, gates, cupboards and outdoor furniture. A valve behind a locked private courtyard or equipment hemmed in by joinery can create an everyday management problem even if it was accessible during construction. The designer should coordinate the final layout with the product and authority requirements.
Discuss what happens when one household is away. Who can reach the relevant isolation point, and how will a tradesperson get there without entering private rooms unnecessarily? The answer may involve gate access, a clear label or a different equipment position. Record it at handover. This is especially useful where the granny flat is occupied by an ageing parent who wants independence but may prefer a family member to coordinate repairs. Avoid an arrangement that works only because one person remembers where everything is hidden.
Review electrical capacity against the actual appliance list
Give the electrician a realistic list of the appliances and equipment planned for both dwellings. Include cooking, hot water, heating and cooling, laundry and any other significant proposed equipment. Identify future intentions separately from items being installed now. The electrician needs to assess the existing installation and proposed demand; spare-looking space in a switchboard is not a homeowner's test of capacity. Ask for the assessment and any required work to be explained before ordering appliances or accepting an electrical allowance that assumes the main house is already suitable.
For the network side, use Evoenergy's connection guidance and have the electrician confirm the applicable requirements. Its Service and Installation Rules address secondary residences; do not assume a second building automatically receives a separate network service. Ask the electrician to distinguish the supply arrangement from metering and retailer arrangements. The homeowner should come away knowing what is proposed, which parties need to act and which decisions are still waiting on confirmation.
Separate a meter from a billing agreement
A physical meter, a usage reading and a separate retail account are different things. Ask the relevant provider or trade what the proposed arrangement actually gives each household. If the owner intends to recover utility costs from another occupant, obtain advice on the applicable agreement and rules before presenting a simple split as settled. A building quotation should not be treated as advice on tenancy charges. Keep the practical design decision and the financial arrangement connected, but do not let one stand in for the other.
For family occupancy, discuss how changes in use will be handled. Someone may start working from home, add equipment or spend an extended period away. Decide how the households will review their arrangement rather than relying on an unwritten assumption that both will always use similar amounts. From the construction side, preserve useful records of what each circuit, valve or meter serves. Clear identification helps future occupants and trades understand the property even if the original family arrangement no longer applies.
Decide how the internet reaches the dwelling
Write down whether the intended service is shared from the main house or independently arranged. nbn's granny-flat guidance explains that a dwelling sharing the primary residence's address generally cannot simply order another network connection; the available options depend on the circumstances. Confirm the specific address and service proposal with the provider early. Do not assume adding a letter to a house number or putting a second router in the garden creates an independently recognised connection.
Ask an appropriate communications professional to design any cabling and equipment arrangement. Explain whether the resident makes work calls, uploads large files or needs a reliable connection for particular devices. A signal check while standing in an empty garden does not demonstrate performance inside the finished dwelling. Coordinate the intended equipment position with joinery, power and the desk layout. For a studio used for work and sleep, include where screens and equipment stay when the room changes use, so the connection does not depend on an awkward temporary setup.
Put hot water and outdoor equipment on the drawing
Ask the designer and installers where hot-water and heating or cooling equipment will sit, how it is serviced and which household controls it. Compare the positions with bedrooms, sitting areas and paths in both dwellings. The selected product's installation requirements should guide clearances and access. Equipment should not be left to occupy whatever space remains after the house is designed. If an outdoor unit is proposed beside the only side passage, ask how people and maintenance personnel will use that route in the finished arrangement.
Keep the appliance choice connected to the electrical and plumbing design. Substituting a product late may change its installation needs, dimensions or the work required around it. Request a coordinated review rather than treating every replacement as a cosmetic selection. Discuss the ordinary user controls too: where they are, how the resident changes settings and who is called when the equipment stops working. Include those instructions with the handover package, especially if the main house and granny flat use different systems that could easily be confused.
Coordinate underground routes before paving
Put all proposed underground work on a coordinated plan so that each trade understands the overall arrangement. The trades need to determine suitable routing, separation and installation details; the homeowner should not improvise a shared trench based on convenience. Ask whether planned paving, fences or retained trees affect access for the work. Compare the service route with the construction delivery route, because a narrow side passage may need to serve both purposes at different stages of the project.
Before excavation, the contractor should obtain the relevant information and carry out the required investigation. BYDA's guide to utility plans warns that plans indicate the presence of infrastructure rather than its exact location. Share any private service records you have as well. Ask how discoveries will be reported and agreed before a route changes. Preserve final records of installed routes where available; they are useful when the next owner wants to repair a path, add landscaping or investigate a service fault.
Plan interruptions to the occupied house
Ask the builder to identify work likely to interrupt the main home's water, power, communications or ordinary access. Get an agreed notification process and a contact for changes. If someone in the house depends on particular equipment or receives scheduled support, tell the contractor early so appropriate arrangements can be made with the relevant professionals. The purpose is to make the constraints known before a connection day, not to assume that the household can adapt to any shutdown with little notice.
Clarify which services will be available to trades during construction and which are reserved for household use. Discuss temporary arrangements through the contractor rather than improvising extensions or connections yourself. On a shared Canberra block, the same side path may lead to meters, bins and the work area, so timing and physical access need coordination. Record the agreed arrangement in the project documentation. A named person responsible for notifying occupants helps prevent each trade from assuming that someone else has explained an interruption.
Ask for a useful services handover
At completion, request a walk-through showing what serves each dwelling and how the resident operates ordinary controls. Keep product information, relevant certificates, provider details and records of the installed arrangement together. Ask the trades to demonstrate the intended isolation and user controls without inviting the resident to open or work on equipment they are not qualified to handle. Labels should match the explanation. A folder of documents is more useful when the occupants can connect it to the actual items on their property.
Finish by checking the service scope against the original responsibility map. Confirm which applications and connections are complete and identify any outstanding provider action honestly. An installed outlet, pipe or piece of equipment should not be treated as proof that the intended service has been commissioned and is available. Agree who demonstrates operation and who resolves any remaining issue. For the wider proposal, use the quote comparison guide; for shared access to equipment and outdoor space, review the privacy guide before the final gates and screens are installed.