Perhaps you fear he is spending more time than he should with a secret mistress or the heating is busted or something ?

Joking aside ~ 70kW hours per week, 11kW hours per day the rate 1 seems quite a lot for a small and well-lagged flat, - but then it is heating and water and everything.

First check it is the right way round, but usually rate 1 is the low, or night rate  and rate 2  is the normal or day rate.
I presume the meter switches  all loads to rate 1 after hours, not just the heaters, and he is out at work during the day and does not do a lot of electric cooking.

The rate 2 suggests that there is very little on during the day, perhaps a fridge freezer and an internet connection.
Does he  go abroad for the winter ?

Or, were the bills before the smart meter much higher ? maybe some stuff has been mis-wired  on the non-metered side, or connected to a neighbours meter.

Mike.

Thanks.
I've made some progress and downloaded the half hour usage.
Yesterday, the flat used 13kWh during the night (Midnight to 7:30am) and 13kWh the rest of the day, but the TOU2 meter reading went up by 1kWh.
Does anyone know how the meter "knows" whether is it TOU 1 or TOU2 and whether this information can be read on the meter? I've downloaded he 120 page manual and timings are not mentioned anywhere. Does Octopus use the half hour readings and calculate it at there end or does it read TOU1 and TOU2 separately from the meter? 
Also, where can I find the Economy 7 times? 

Thanks

Yes, he does go abroad in the winter and leaves the storage heaters on lowest setting.

Yes, he does go abroad in the winter and leaves the storage heaters on lowest setting.