Cables passing through post and beam floor - What is recommended for cable transits?

[barnsley boy]

I am project managing the build of a conservatory (I'm also the client). As the house is raised above the patio level, we have decided to use a post and beam floor. The existing house outside wall will in time be an internal wall to the conservatory and be wooden battened and plasterboarded. I need to provide space for cables/refrigeration pipe work (for air con). In a previous life dealing with pressurised instrumentation buildings, we'd use Hawke transits, but these will be a big overkill in this case. I was thinking of using solid plastic pipe work supported by the floor beams and when used filling with expandable foam. Is this the best way?