The Maximum Rent limit varies from County to County - for Co Louth, the maximum rent limit for one (or 2) adults with one child is €160 per week. If you rent a property with rent greater than this amount, you won't get Rent Supplement at all.
Your maintenance will be part-assessed when calculating how much rent supplement you may be entitled to.
Maintenance is assessed as follows for Rent Supplement:
The first €95.23 is assessed in full.
The next €75 isn't counted
Anything over that amount (€170.23) is assessed at 25%.
So your maintenance of €200 is assessed as -
95.23 + (25% of 29.77) = 102.67 weekly means.
If you rented a property at €160 per week, you would have to pay 102.67 + 18 (minimum contribution everyone on rent supplement has to pay) of the rent yourself, so you would receive rent supplement of approx €40 per week.