Always do the things that are really tough to do after the fact.

Is the 2 zone heating a single unit with dampers and a control unit? Or is it two full units. We have our 1st floor and Basement on one unit, with two thermostats and dampers controlling the flow. The HVAC was loud until we finished the basement, because it was blowing too much air.

Are you on a well or city water? A sprinkler system can usually be retrofitted after the initial build. You can even DIY it.

Brian

Consider manual dampers on your HVAC system, with access ports (we can adjust ours by reaching into our vents or from our furnace room), which allows us to adjust airflow rates to different floors and rooms. Not as good as 2-zone HVAC, but it cost about $20 in dampers and maybe an hour of work.

I can't imagine why it would cost $1600 to add a thermostat and a damper. The air ducts are already in, aren't they, or is the alternative an unheated basement? If the ductwork is installed, you would be heating and cooling you basement unnecessarily. Why heat the basement in the winter unless you are living in it? Ditto with summer cooling. Remember without the thermostat both levels will have to reach the same temperature and will be very wasteful. You can add dampers and thermostats later, but it would be more expensive. By the way we also had a separate zone for the master bedroom, so it is controlled at night for sleeping and off during the day. Let's pick another thing to save money on. Is the basement finished?

Typically you want to not skimp on anything underground and want to keep what is difficult to add later. You can go easy on things that are easily replaced. Seems to me a lot of variation in the cost of a build comes from material selections...choice of counter top material alone can be thousands of dollars...$10k doesn't seem like such a large discrepancy that it can't be met by altering some other choices.

If you are finishing a basement, 2 zones would be, IMO, essential.

Can you just forestall finishing the basement at all at this point and just plan on doing what is essential so that at a future date it can be finished the way you want?

We have outdoor spigots on our house for watering plants and such and needed no oversized plumbing to accommodate it....

I'm with Annie on the oversized plumbing. Can't understand what you are referring to.

I am located in the Fox Valley. My wife and I will hopefully be breaking ground this fall.

I have found that around here basements, even if walkout, don't bring back a whole lot of appraisel value during new builds. My best suggestion is maybe look at the finishes you are using in your basement and cut back.

I would not cut back on the second zone. Friends of ours built a new net zero house here in the valley. It is an extremely well insulated ranch with a walk out and this past winter because of only having one zone there basement was always 6-10 colder then the upstairs. Needless to say they have now a second zone.

Best of luck

You can always add a heat pump mini split (later) to heat and cool your basement.