Hi Eloise73
Carer's Allowance - earnings less than £100 pw post tax/NI/childcare, caring for child over 35 hours per week - £53.90
Tax Credits - You would get the 'disabled child element' for middle rate care, which is £2715 per year (£52.21) per week, although the actual rate is pro-rated according to your income.
Housing benefit - is strictly income based, not based on 'deservedness'. You would get an 'applicable amount' which is made up of elements for your family Here
Basically, you add up all that apply to you, then they take away that amount from your income. This is called the 'excess'. They expect you to put 65% of your 'excess' towards rent.
The good thing is that your applicable amount will go up by £52.08 for having a child with a disability (and a further £21 if the child gets High Rate Care), and you also get a 'carer premium' which pushes your applicable amount up £30.05. So the effect of that is that you can have £82.13 more each week coming in (or £103 if your child gets HRC) before your HB is affected.
Each area is set a Local Housing Allowance, which you can find by using this site.
Firstly, calculate how many bedrooms you are 'allowed' (1 for each couple, 1 for each single adult over 16, 1 for any 2 children of the same sex under 16, 1 for each opposite sex child over 10) and then use that to find out the LHA rate for your area with the number of bedrooms you are allowed.
So, if you currently rent a 5 bed house, but only 'allowed' 4 beds, you calculate it all on the 4 bed rate, and you would have to make up the rent after that.
Turn2us which used to be 'entitledto' will work it all out for you if you use it to put your details in.