A 4BR house that claims to use 1/3 the energy of an average house and people go 'wow it looks just like a normal house, without solar panels or a wood heater and it can do that?!'
Maybe you should visit a few more homes dyno.
re the Greywater comment.
Some of the SHD houses have done just that - they mandated to the builder that they wanted seperate piping for grey and black and guess what - they got it.
One of them cannot even use a greywater system due to water tables under the house - but they have piping sperated so it allows them to do it in the future if possible.
Which is what it is all about - planning for the future.