Water mains connection

[Omi]

We are getting close to starting the groundworks on our build and had a couple of questions:

 

1. Where the water mains comes into the property: we are planning to have this come into the small plant room in the under-stairs space. This would seem to be logical as the DHW cylinder is going to be directly above that space on the first floor. Are there other considerations we need to keep in mind?
2. Mains pipe requirement. Scottish Water requires a barrier pipe for the run from the existing mains to the boundary box as it runs under the carriageway. However, the service line from the boundary to the house is also currently specified as a barrier pipe. Possibly as a safeguard as a section of it passes through the driveway. Is it really necessary to have this final stretch as a barrier pipe as well? Barrier pipes seem to be mainly required for brownfield sites where there may be ground contamination present but the one we are building on is greenfield (previously farmland). Would be good if we can avoid having this final stretch as barrier pipe as the piping and fittings seems to be about 10x more expensive than the regular MDPE variety. On that note, would a 32 mm barrier pipe take a regular 32 mm stopcock?

 

Appreciate any feedback from the collective wisdom and experience of this forum ? Thanks!