I'm sure a suitable alternative can be found that doesn't involve a 'swap' with a smaller family.
For a start, old council houses need to be ripped down and replaced. They've done this over the past few years in the Craigmillar area of Edinburgh, and it's had a really positive impact on the community - but that's going off on a tangent, sorry.
Regardless of the rights or wrongs of the parents, the children have done nothing, and deserve to live in a decent house in as best an environment as possible.