Fresh water, power, and data are distributed in a 4” bundle of flexible corrugated ABS pipe. Wiring is slightly coiled to allow for flexing between modules. The bundle is cast into the module through the cellular concrete layer (routing through the normal density concrete layer would compromise the structural integrity).
The distribution grid of parallel rows shown is simple, conservative of materials, and redundant enough to survive single breaks in each row.
Power is distributed as 240VAC, 2-phase plus ground. Data is optical fibre (Sonet? Fibrechannel?). All telecom, entertainment, and data services are common-networked digital.
Air circulation is provided through 4” corrugated flexible ABS pipe cast into the top surface layer of cellular concrete. The central plenum passes through the utility room where a fan circulates a controllable mix of inside and outside air through optional heating and cooling. Outside air is drawn from a vent on the roof of the 'conning tower' via a snorkel valve to preclude admission of water.
A handy feature would be some kind of float-valve mechanism to prevent the transmission of water between rooms via the ventilation system in the event of partial flooding. This sounds too complicated and expensive for the standard module design.
Sewer collection is an unresolved problem. Utility hookups need to be made near the top surface of the modules to avoid the maintainance difficulties of submerged sewer connections. But off-the-shelf plumbing components assume gravity drainage. Plumbing fixtures inside a module would have to drain to a submerged collection network. A related open issue is disposal. Simply dumping sewage 'overboard' is not acceptable for relatively fixed platform arrays a few feet above the surface. Voiding to an outlet at several hundred feet is slightly more palatable. If this route is taken, salt-water toilets will be a necessary evil. Recycling through methane generators and/or greenhouse agriculture would be a better solution, if possible.