No gutters? That's a problem because you want to get water away from the foundation. Adding gutters would be where I would start.

No drain whatsoever? Do you have a sump pump? If you have no sump pump, you have no drain tile around the foundation.
You may have ground water with no way to eject.
Get after the builder NOW, while you still have a warranty.
Warranty - HA! - that's an entirely 'nother subject.
Experience shows a builder will stall until you have no recourse.

You have two issues. The first in bulk water, in your case very likely the result of no gutters. It's hard to believe that's allowed in new construction anywhere! I didn't have gutters on cottages built on stilts on bedrock. Different matter.

The second is vapour diffusion, which you can't avoid and the builder evidently didn't take any measures to reduce and isn't required to.

There are approximately 300 pounds of water per one cubic yard of concrete. As your new slab and walls cure, that water has to go somewhere. As well, unless there is a sub-slab vapour retarder, moisture from the soil will be forever infiltrating, as will moisture through the walls. As well, in the summer, moisture will be drawn through the above grade sections of your basement. The hotter and more humid your environment, the more moisture you will have in your basement.

The relative humidity in your basement should be below 50% to deter moisture problems. You need a hygrometer to accurately measure it. If one dehumidifier doesn't do the job, get another one. (I run two units 24/7 in the summer--in a 50-year old house with no moisture retarders anywhere in the basement.)

Do NOT attempt to dry your basement by keeping the windows open. This just brings in more humid air. Do not store cardboard boxes on the floor. We have a lot of storage in our basement; I just knocked together 2x2s under OBS, which also saves us on the occasional minor flooding.

Here is a link that might be useful: Investigating and Diagnosing Moisture Problems

There are 14 houses in this new development and none come with gutters. We are thinking about installing some, but haven't gotten any quotes yet.
We don't have a drain in the floor anywhere and I dont think we have a sump pump (not sure how to tell, but there isn't anything I can see).
We were hoping to finish the basement in the future (not for a few years..but down the road). I don't know exactly what the warranty covers, I'll have to look that up. I haven't heard any of the neighbors complaining about basement problems but maybe I'll have to ask around. Ours was the only one built this winter (foundation poured in January) and I know they used some sort of additive to help with it curing.
ANyone have an estimate of how much it costs to add a drain/sump pump?

Here's a quote from our warranty. SOunds to me like we're on the hook if it's condensation???:

"We Warrant that the concrete foundation and floor will be free form seepage and leakage and surface water for a period of one year from teh closing date. However, it is impossible to assure you that condensation will not occur as this is the nature of new concrete, and therefore, we expressly do not guarantee against dampness by reason of condensation. Moreover, it is the homeowners responsability to correct any minor settlemet near the foundation, which may cause water pockets. Not covered by this warranty is seepage due to unusual flooding or rains greater than two inches in 24 hours. IN the event that it is required to correct a seepage problem, the same will be corrected at sellers expense by the installation of a perimeter drain and or pump at the sellers discretion. IT is not possible to prevent concrete from minor cracking because of the nature of the material. All major cracks that emit water are covered for 1 year from date of closing."

Ditto mike kaiser - Don't know in what part of the country you are, but first I think you need gutters and downspouts, for sure. Opt for the largest, you won't be sorry, 4" standard are just too wimpy. Next, be sure your grade is sloping away from the foundation and channel rain runoff away from the house for several feet with some kind of pipe, pvc, extra gutter pieces, etc., whatever works. If the slope is good you can bury it almost up to the end. Big box stores have all kinds of solutions to deal with the drain ends, little grates, popups,
etc. so you don't run over with lawn mower.
As far as drain tiles and sump pump and/or ejector pump, you need to get estimates. It's not cheap, perimeter of the foundation would have to be dug up, and a sump pit installed, but in the long run will save you headaches and heartaches.
It might not be a code issue in your area, but I still would be outraged at the builder.

Rushing to spend thousands of dollars for excavating, waterproofing, drains and sumps is a mistake when all you have may be nothing more than normal condensation and moisture laden air.

Getting the bulk water away from around the foundation is a necessity though.

Thanks all,

We're going to get estimates for gutters and also buy a 2nd dehumidifier for now and see how it goes I guess...

My house has no water intrusion in the basement. As Worthy points out, there is lots of water used in masonry and concrete. It took my basement over a year to get to the point that the dehumidifiers were not running most of the time. Now they capture less than 5 gallons a week combined for both of them.

went out and bought a new dehumidifier last night. It holds at least twice as much as our old one and seemed to be doing a much better job. I guess we'll start with that and see how it goes. According to the setting, it was able to get it down to close to 50% humidity (from around 75%). It did fill up overnight so we emptied it this morning. The humidity reading was back up high again though when first turned it back on this AM.

Thanks for the info...

" As your new slab and walls cure, that water has to go somewhere."

Most of it actually stays in the concrete forever as it cures by hydration.

Any excess will come out.

You can test for condensation by taping some aluminum foil to the concrete with plastic tape (gaffers tape or packing tape work), allowing the foil to stay in place for a day or two, then removing it and seeing if there is a wet spot on the concrete, or on if the surface of the foil that was exposed to the room is wet.

The room side is condensation, the concrete side is water in or moving through the concrete.

WIth the lack of gutters, your design may rely on a perimeter drain and grading to keep outside water away from the foundation. Combined with proper grading, the lack of gutter MAY not be the source of your problem. Gutters can't hurt, but they might not be your solution.

My last house had a basement with no water problems. Occasionally during a hard rain we would see some water in a corner of the basement. I quickly found the problem was a downspout which came undone and was dumping water directly against the house. The "pool" of water sitting against the house cause some seepage.

WIth properly built new construction, I would think you would need an especially wet season and/or some grading issues to cause major water problems like you describe.

One previous suggestion regarding opening window I do disagree with. I understand the reasoning, but I have had different experience.

I recently had a home built. The foundation was poured in the winter and some snow accumulated on the concrete. The house was built and the snow (small amount) was not removed.

Fast forward to the summer. The house is built, but the interior cutout for the basement stairs isn't done yet (it is a walkout basement, so we still have access via sliding doors).

I started having what I though were water problems. Dampness about 18" from the floor on the foundation and standing water on the floor. I wasn't living there yet and couldn't get to the location regularly. I would get everything "dry" only to find water next time I came there.

I called the people who did the foundation. They confirmed perimeter drain, vapor barrier, waterproofing exterior, etc. were all done. We were scratching our heads as to the cause. My contractor suggested condensation. With the amount of water I was seeing, I was tempted to laugh at him. However, I did try the aluminum foil trick mentioned above. Took an 18" square of aluminum foil (saran wrap works just as well) and duct taped it to the wall in several place.

Oddly enough, I never got to test this trick. The day after I taped the sheets is the day they cut the hole for the basement stairs. Contractors were working on the house all week and the doors/windows were open. (Granted, it was not a humid week and we had a good breeze). After that, I have had NO water problems.

Moral of the story - the house was built so tight, the original water was trapped in the basement. It would continually evaporate and condense. WIth no air flow, it had no where to go. Once we had some air circulation to/from the outside, I was able to get rid of the water. Since I had no real seepage/leakage problem, the water never came back.

One last thing... they make dehumidifiers with a built in pump. I like the "Winex" model. It has a standard reservoir plus it can pump water up to 15ft vertical. Much easier than emptying a bucket every day.

"they make dehumidifiers with a built in pump"

Or you can just connect any dehumidifier with a drain hose to a condensate pump purchased separately.

The pumps are not very expensive.

We have a similar issue (in SE WI). We have gutters and we do have 1 sump pump. We have been running a dehumidifier non-stop! our house is about 8 mos old (we moved in in April 2015). We JUST found mold on the I-beams and on some boxes (some boxes felt damp). We just bought a second dehumidifer. Will our basement always be humid/ damp? Thanks!