My Dad Died Without a Will — Does His Partner of Four Years Get the House Over Us Kids?

I'm sorry about your dad. Sudden losses like this are hard enough without an estate question landing in the middle of it. General information only here, not advice for your specific situation, but I can at least map out how this generally works.

Yes, a de facto partner is generally treated much like a spouse under intestacy in every Australian state and territory now, provided the relationship meets that state's definition of de facto, commonly a minimum period of living together (often around two years, though it can be shorter if there's a child together or the relationship is registered). Four years living together would typically clear that bar, but "typically" is doing some work in that sentence: the actual test looks at the whole relationship (shared finances, how the household ran, how the relationship was represented to others), not just a headcount of years. Denise would generally need to formally establish the relationship as part of the estate process. She can't just assert it, and neither can you dismiss it without checking.

Whether it beats the house being solely his name is a different question. How long he owned it before the relationship, and whether it's in his name alone or jointly, matters for how it's treated, but under intestacy the house is just another estate asset once ownership is established. Solely-owned property doesn't sit outside the formula the way a jointly owned home would (that passes straight to the surviving co-owner, no estate involvement at all). Since it's solely his, it's part of what gets distributed.

The formula itself: this is genuinely state-specific, so I'll describe the general shape rather than numbers I can't guarantee are current for your state. Where there's a partner and children who are not also the partner's children, most states split the estate: the partner typically receives the household chattels plus a statutory legacy (a fixed amount set by regulation and indexed periodically) plus a share of what's left, with the remainder divided among the children. It is very rarely "partner gets nothing" or "partner gets everything" in a situation like yours. It's usually a split, and the exact proportions are the part worth getting a firm answer on rather than guessing from a forum post.

Practically: none of you can transfer or sell anything yet. Someone needs to apply for letters of administration first, which is the no-will equivalent of probate (more detail in what happens if someone dies without a will). Given there's a genuine question here about entitlement, a real asset at stake, and people who aren't necessarily going to agree, this is a case where paying a solicitor for an hour of advice (not necessarily to run the whole thing) is worth it before anyone says something they can't walk back. It's a lot cheaper than a dispute that's already hardened.