I'm hoping somebody else will have posted some realities in this thread already, and I do apologise if so as I'm too lazy to read through.
I worked as a Housing Officer at a Local authority making enquiries and ultimately written decisions on homeless applications. I now work for a charity giving legal advice to the homeless and scrutinising LA decisions.
Being evicted for rent arrears does not automatically equate to being intentionally homeless.
Under Section 191 (1) of Part VII of the Housing Act 1996, a person only becomes intentionally homeless if;
'he ceases to occupy accommodation which is available for his occupation and which it would have been reasonable for him to continue to occupy'.
I cannot stress quite clearly enough that you CANNOT be found IH from an unaffordable property.
-If a property was always unaffordable from the day you moved in, the LA will not deem it to be 'settled' accommodation and they will have to look back at to the property prior to that to determine whether it was both 'available' and 'reasonable'.
-'Reasonable' also covers criteria such as disrepair and overcrowding. If the prior property still wasn't suitable, the LA will keep looking back until they find somewhere that was suitable. I've seen people found intentionally homeless from properties they vacated 8+ years ago.
-If a property became unaffordable at some point during the tenancy, then the LA would have to consider whythis is. For example, I found somebody intentionally homeless for having been found guilty of racially aggravated assault against their manager, thereby losing their job. Their benefits then didn't cover the rent in full, and they built up arrears. However, I found that we owed a duty to the chap who was simply made redundant and could not longer afford to pay his rent.
The part VII housing legislation has largely been clarified in many parts by a code of guidance from 2006, but there are an absolute wealth of interesting case law on the matter of homelessness.
An utterly fascinating job but times are fucking tough right now, and I am so glad that I'm the one scrutinising their decisions now, rather than making them.