The problem in one sentence
Neither property is empty, so neither family can unload until the other has loaded — and if both start at the same moment in the same way, both end up sitting in a full van waiting for the other one.
That is the entire difficulty. It is not about carrying and it is not about distance. It is about order.
Get the two removers talking
This is the single most useful thing anybody does on an exchange, and almost nobody does it. Two families, two removal firms, no contact between them, and a plan that exists only in each household’s head.
One conversation beforehand settles who loads first, who unloads first, and what happens if one side runs late. Ask your remover to make that call — if they will not, that tells you something.
Decide what is not coming, before the day
Exchanges very often involve a change of size, and what does not fit has to be dealt with somewhere. The pavement outside a property that somebody else is about to move into is the worst possible place to work that out.
- Measure the rooms in the property you are swapping into, especially for beds and wardrobes.
- Decide what is being sold, given away or disposed of, and arrange it in advance.
- Empty the loft, the shed and the garden. Those are the classic leftovers.
- Do not leave anything "in case they want it" unless you have actually asked them.
If the other side is not ready
It happens. Somebody is ill, somebody’s van broke down, somebody underestimated how much they had. It is not usually anybody being difficult.
The workable answers are: wait, if the delay is short; unload into one room and sort it later; or put the load into store overnight. All three are much easier if the two removers have already spoken.
Leave it as you would want to find it
You have met this family. They are about to walk into the home you are walking out of, and vice versa. Clearing properly, leaving the meter readings and not leaving a pile in the garden costs very little and matters a great deal.