I have a lot of sympathy for the family but as I read it, he's in married quarters. The point of married quarters is that it's provided by the army for serving married soldiers and their families.
Children with disabilities are catered for in terms of accommodation by local authorities. Specially adapted homes are actually fairly commonplace in terms of the need.
It seems to me that this Soldier needs to manage his transition from married quarters to another specially adapted home so that his disabled son doesn't lose out in terms of the care that he needs.
That might sound glib but I realise that dealing with local authorities isn't always the easiest thing to do and he probably needs advice on who to approach.
If he knows where he wants to settle down, he should approach the local social services department. This child will be known to them anyway because he's probably already using some services from them. It's time for the social worker to "earn their pay" as they say.
If he's not happy with progress, he can get on to a Councillor from the local authority who should be able to prioritise their efforts to assist the family and hopefully move things along. Of course, there is also the local Member of Parliament route as well if he thinks it will help.
I wish him luck and a speedy conclusion to his housing needs for him and his family.
The Council will work on the principle that there's no hurry because he has somewhere appropriate to live. The MoD will be trying to hurry them up and the quickest way to do that is to apply for and obtain an eviction order, that lights a fire under the Council who have to pull their finger out. For the MoD it's called negotiating from a position of strength and is a well established route for getting ex-services the accommodation they need in civvi street.
I don't know if my heart strings have been plucked once too often.......
but........"Boo Hoo Hoo I'm being kicked out of my speshull house, wiv my speshull kid by da baddass Army, a house to which I am no longer entitled, a fact I've known for years........Boo Hoo Hooo but I'm well speshull me!"
......Well it didn't work for me!
Perhaps I should get therapy.......and make a claim....over exposure to media inflated tales of ex squaddie bad admin woe has made me really f@cking callous....then I too would be speshull....perhaps I'll get his house!
ISTR reading that he had been "ordered" to sign some document signing away pension rights as the only option to being discharged, under some manning review, when his wife was pregnant ( and very ill with pre-eclampsia or summat ) 14 years or so back; he declined and was dicked about as a result, which didn't help his wife's condition. I don't recall the details, so the above is probably all wrong.
I suspect (but don't know) that the real cause of this is that the local authority won't rehouse them because they aren't homeless. When they get evicted, then they are homeless, but can't leave the MQ before that because they'd be making themselves voluntarily homeless and so not eligible for council housing (edit; much as Markintime said, but he cunningly waited until I'd started fat-fingered typing before posting)
It all makes for a good day-trip for the outrage bus.