Reading through this interpretation of the requirements for de facto relationship, the 1 year period of relationship does not necessarily mean that the couple has lived together for that year.
https://www.australiavisa.com/immigration-news/know-de-facto-relationship-requirements-differ-visa-subclass/
Period of relationship
The de facto relationship must have existed for at least 12 month before the time of application for only the following visas:
Any permanent visa
General Skilled Migration (GSM) visa (subclasses 189/190/476/485/489/887)
Partner visa (subclasses 309/820)
Student visa (subclass 500)
Business Skills (Provisional) Visa (subclasses 160/161/162/163/164/165/188)
De facto relationship requirements for other visas are not required to fulfil a prescribed period of relationship requirement. For example, the Temporary Work (Skilled) visa (subclass 482) has no minimum 12 months requirement for a de facto relationship.
The minimum 12 month de facto relationship requirement does not require the couple to have been cohabiting for 12 months, but that their relationship meets the basic criteria for a de facto relationship for at least 12 months – minimum age, not married, mutually exclusive, genuine and ongoing, not living apart on a permanent basis and not related by family.
If compelling and compassionate circumstances can be produced, the minimum 12 months de facto relationship may be waived. Compassionate and compelling circumstances may include there being a dependent child from the relationship, if the relationship is same sex and is illegal in the applicant’s country, if a same sex couple has legally married overseas. A sponsor or applicant being pregnant at the time of application is not considered compelling and compassionate circumstances unless there are exceptional or unique circumstances relating to the pregnancy .
Alternatively, if the relationship is legally registered such as the NSW Relationship Registry, the couple may be exempt from the minimum 12 month requirement. The certificate for registration must be provided; evidence of having made an application is insufficient when the case officer asks for it however it is possible to lodge the application as long as the signing process has been completed. Not all states are accepted under this provision.