It normally includes all costs that were needed for the actual build of the working house, including utility connections, runs for foul drains, rainwater drains, power and phone cable runs and gas pipe runs.
It's not normal to include plot costs, or landscaping costs as a rule. For example, we bought our plot relatively cheaply (around £50k under market price) but then spent a bit over £50k getting it level and suitable to use as a building plot, and those plot levelling costs weren't included in our cost per m² to build the house, as I considered them to just bring the plot up to its market value. I did include the cost of drilling our water borehole and installing the treatment system in our build cost per m², as that was equivalent to a utility cost, in my view.
I'm really confused as to how the heck any form of CaCO3 is actually in the mains water. Ignoring all the other elements/compounds for a moment, hard water that only has hardness resulting from calcium, will have the following formula:
H2O + Ca2+ + 2HCO3-
There is no CaCO3 in the incoming water, so there cannot be any, in any polymorph, in the water leaving your device unless your device somehow causes CaCO3 to be formed and precipitate out. It matters not how this formation and precipitation happens, but the fact is that the solubility of CaCO3 in water is such that it would just dissolve again soon after leaving the unit, and the water would once more turn back to H2O + Ca2+ + 2HCO3-
I cannot find any evidence anywhere as to how this process of forming CaCO3 under conditions that are not normally those that would initiate its formation and precipitation from H2O + Ca2+ + 2HCO3- actually happens. What's even more puzzling is how the CaCO3 that is precipitated out of solution in the form of aragonite, isn't then subsequently dissolved again.
Of course it's plain nonsense to suggest that calcite enters the device with the incoming water, it cannot, as mains water that is below super-saturation point doesn't contain any calcite at all.
FWIW, MBC had virtually nothing at all to do with my windows and doors at all. They made the frame to my design, in terms of overall dimensions, door and window openings, etc. Their only intervention was after I'd complained (in passing) that the window company were a bit of a shambles to deal with. Unknown to me their MD took the trouble to drive down to Cork and give the window company an earful on my behalf; something that they didn't need to do and weren't in any way contracted to do - windows, doors and all the relevant opening sizes and specifications were 100% my responsibility, right from the very start (in fact it's written into the MBC contract that all that stuff is my responsibility, as was loads of other stuff like me providing the scaffolding as required and on time, me providing skips as required, toilet, hand washing and first aid facilities etc, etc. The contract is a dozen pages long and is crystal clear as to what was my responsibility and what was theirs, which is one reason why I can't understand why some seem to think that project management was in any way a frame companies responsibility - it's clear in my contract that it's my job to sort that aspect out.