I actually rather like the house - I like modernist boxes.
Several buts, though, since I know the place.
The location is quite good for the station, but the hill up to South Park is a BASTARD. We lived there for a few months when I was a baby and my mother still talks about getting up it with a pram or in car in snow or ice.
There were problems with flooding at the end of Plymouth Drive for years and years. I'd not trust it.
I think it's overpriced. I've seen nicer houses (fewer bathrooms but proper outside space, individual builds) go for much less than that in the last year.
So it's a nah from me. For 1.5 million you can live somewhere nicer, even within walking distance of Sevenoaks School, if that's what you're after.