Disentanglement.

One of my greatest fears is to have a failure in the heating system's PEX tubing, which is inconveniently entombed within the concrete slab of the barn. Having thought about if for a few years now, it just doesn't seem like a good idea to seal off any electrical, plumbing or HVAC systems behind walls or under floors- while it may be aesthetically pleasing to have the nervous system of the house well hidden from sight, this makes it difficult if not impossible to upgrade or repair things that break...and sooner or later everything needs fixing, right? Alternately, the concept of disentanglement keeps these systems separate and accessible, usually in chases, raceways and conduits, to increase the adaptability and longevity of the building. I like it, and kept the idea in mind when installing the HRV system, as well as plumbing and electrical runs going to the upper floor of the barn. With all the utilities in place, it looked like this:

Then I built removable soffits and a chaseway to cover it all, which looks like this:

Admittedly, the wood soffits wound up being quite heavy, but can be removed if necessary without destroying anything.