Heat pump STCs are tied to a product and an installation. The Clean Energy Regulator (CER) asks three things: is the exact model on the register, was it installed correctly, and is the right installation type recorded. Whether the building is a first home, a rental or a workshop matters far less than people expect. For the basics of how the certificates work, see heat pump hot water STCs.
New builds
A heat pump installed in a brand new building can create STCs. The entitlement arises from installing an eligible system, regardless of whether the building is new or existing. The catch is classification. In a new build there is no old system to replace, so the claim is a new installation, and the evidence is different from a swap-out. Our installation type guide sets out the three types. Builders sometimes also face state energy or hot water rules in the building code, which can limit which systems are allowed, so check those separately from the STC rules.
Granny flats and secondary dwellings
A granny flat is a separate dwelling with its own hot water system, and the STC process does not care. Record the address of the unit the heat pump serves, use the owner’s details on the assignment form, and make sure the photos show the system in the granny flat, not the main house. The climate zone is set by postcode, so it will match the main house.
Rentals and landlords
The owner of the property decides on the replacement and signs the assignment form. The tenant is not the claimant. Landlords can generally take the STC discount on the quote, and tenants gain lower running costs. If a property manager is signing, make sure they have written authority from the owner, because a form signed by the wrong person is a common reason claims are questioned. See the assignment form guide.
Commercial sites
Businesses can claim, but the product is the limit. Air source heat pump water heaters on the register are capped at a storage capacity of no more than 425 litres, and solar water heaters have their own capacity rules. A large commercial plant outside those limits will not create small-scale certificates. For solar generation above 100 kW, a separate rule applies, covered in mid-scale solar STCs, but that does not extend to hot water.
From the desk: commercial owners often ask about GST and depreciation as well. An STC discount can change the taxable amount on the invoice, so get your accountant to confirm treatment before you sign.
What this means for installers
Check the model, check the installation type, and get the right person to sign. Our hot water checklist lists the evidence for each job type. If you want a trader that checks the pack before it is lodged, see how it works and pricing, and read the hot water STC pillar.