Build your patio to fall away from the house if at all possible. Draining towards the house can only ever be to entertain a risk of flooding. You must basically create a ventilation duct between house and rear wall of patio to maintain airflow to the air vents and I would therefore suggest a bridge of some kind. As Wild Edges says, this could comprise a row of the slabs adjacent the house raised on feet or props or, for me, a wooden decked section say 1m wide between house and patio. This would also give you the option to raise the patio to step level which will reduce your groundworks and give you a luxury same level transition from house to patio.
I always understood there had to be depth of between 6-9 inches (sorry, don't know what the metric would be) below the house airbricks to the paving/decking etc to minimise rain splash into the holes which could theoretically cause damp egress to the inner wall. Paving must also not be laid above the damp course membrane.
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Draining towards the house can only ever be to entertain a risk of flooding.
You must basically create a ventilation duct between house and rear wall of patio to maintain airflow to the air vents and I would therefore suggest a bridge of some kind.
As Wild Edges says, this could comprise a row of the slabs adjacent the house raised on feet or props or, for me, a wooden decked section say 1m wide between house and patio. This would also give you the option to raise the patio to step level which will reduce your groundworks and give you a luxury same level transition from house to patio.