It was not clear from the description on Hotels.com, but this is actually a single self-contained studio apartment, which is part of the owner's house. It has it's own entrance but shares the same terrace.
We were a bit worried by the fact that there were no online reviews for this accommodation, but after staying there we can assure anyone considering a booking that there is absolutely nothing to worry about.
The apartment is nicely decorated, fully equipped with TV/Stereo/kitchen amenities etc and is spotlessly clean. It boasts amazing sea views from the windows and from the outside terrace.
We would really recommend anyone looking for accommodation in Penneshaw to consider this apartment. The only downside is that Penneshaw as such is not really an ideal base to explore Kangaroo Island. It is really on one extremity of the island and quite far from all the main attraction. Maybe the ideal holiday what be to combine one or two nights here with a couple of nights further into the island closer to the attractions and wildlife.
Note: the map on Hotels.com is correct but the actual "street" number is wrong and there is no signboard so you may want to contact the landlord in advance to get correct directions.