Two of everything, and room for one
When two homes become one, the lifting is the straightforward half. This is the
other half, and it is the part that turns an ordinary Saturday into an argument if
nobody has looked at it beforehand.
Two sofas
One goes. Decide which before the day.
The single biggest item in both households and almost never a case for keeping both. Measure the new sitting room first; frequently neither of them is right for it, which is worth knowing before either is carried up a stair.
Two washing machines and two fridges
One goes, and the other may not fit.
Appliance spaces in a fitted kitchen are unforgiving. Measure the gap and the appliance, in that order. The spare goes to a family member, a sale or a licensed disposal route rather than into a garage indefinitely.
Two kitchens' worth of everything
Merge into one, from the better set.
Pans, crockery, utensils, small appliances. It sounds trivial and it fills more cartons than the bedroom furniture does. Pack the set you are keeping and deal with the other before the vehicle arrives, not after.
Two sets of garden equipment
One mower. One of everything else.
Sheds merge worse than houses do. Two mowers, two strimmers, two sets of tools and four half-used bags of compost, none of which can travel with fuel in it.
Two bedroom suites
Usually one, sometimes neither.
Wardrobes are the piece most likely to be wrong for the new room. If one set is fitted it stays with the property anyway, which quietly solves the problem.
Two of the sentimental things
Keep both. Store what will not fit.
The one category where the arithmetic should not apply. Nobody should be pressured out of a thing that matters in the week they are merging households; that is exactly what listed storage is for.