The safest time to remove a wasp nest is in the winter when all the new queens have gone to hibernate and all the other wasps are dead. This one was in my attic and was probably originally suspended from the roof but it had fallen and was lying on the loft insulation. It was very light and very fragile making it difficult to handle. The nest is made of paper which the wasps produce by chewing wood.
The original nest containing 20 or so cells is made by the queen but after the first workers emerge and mature she leaves them to build the nest and do the foraging while she concentrates on laying eggs and raising brood. The structure of the mature nest is fascinating. When I cut it in half I found a fairly solid core, where the combs were, surrounded by an insulating layer 10-15cm thick.
The combs are single-sided and separated by a space for the wasps to work in. In a bee hive this is called bee space and is about 8mm. Combs in a bee hive are double-sided which makes them more efficient to construct and to heat.
Honey bees and wasps are similar in size so it is no surprise that the structure of their combs in similar. The difference of course is in the material. Wasps chew wood whereas bees produce wax. Wasp combs last for only one season and are used only for raising larvae. Honeycombs are much more durable and are multifunctional - they are used for raising brood but also for storing nectar, pollen and honey. The photo below shows a small piece of wasp comb lying on a frame of honeycomb (the cells are filled with pollen) from one of my hives. The cell size is almost identical.
I'll have to wait and see where the wasp nests appear this year.