NAD house reef has some interesting critters. Black sand in located at one of the more famous dive sites at lembeh so you get that as your house reef.
But i found that the option to do longer dives in lembeh usually means a house reef dive is quite unnecessary. I can do 3 boat dives of 70-90 min each and be quite happy with that without doing extra house reef dives cos it's that good. Also if you want to do extra dives, a night dive in lembeh is a must do. Or you could do the dusk mandarinfish dive and extend the time a bit to a short night dive.