Moisture on outside walls

It indicates those walls are cold, indicating lack of insulation.

I agree...open them up and insulate...HTH...

Call the builder back to finish the job right and put in the missing insulation. And with a screw up like that, better have the house inspected to see what other corners he cut and hid. And while you are at it, retain a really mean lawyer, because you will need one. Meanwhile, start taking photos of all the condensation and other suspicious signs that all is not as it should be. Good luck.

Joe

Hi, Sounds like a poor insulation/vapor barrier or air leakage. RH setting depends on outside temp.

The condensation is most likely warm house air vapour condensing on the first cold surface it reaches. Which could be a painted cold surface, cold window etc. cool water pipes, poorly insulated outside door etc.

Sounds like a lack of insulation in that wall? Something wrong somewhere. Read up on insulation and vapour barriers, in order to talk knowledgeably with contractors/inspectors etc.

Insulation should have vapour barrier on it 'warm side' unless, say, it's the type of foam that provides it's own vapour barrier. Th reason being to prevent warm and therfore inherently more moist house air from permeating into the wall, condensing in there and soaking the wall and any insulation.

Hi, As a one time expensie, one can have a energy audio done for the whole house and owner will know exactly what to do to make the house air tight. My house was built per R-2000 spec. Cost little more but it is warm in winter, cool in summer. I save on energy cost by the substantial amount.

To properly answer your question we need to know more facts. How "NEW" is the house? What is the house constructed of (vinyl siding, stucco, Block, et.)? What area of the country is the house located? And maybe a few more facts.

Also, there could be more than just one thing causing the problem.

Hank

Sounds like missing insulation in those areas.

I'd also verify the humdidity is really 25% by measuring it with a couple different devices. If the humidifier is just set to 25%, the actual humditity could be higher.

Not sure, you need to test it. To be sure it is condensate, tape a square of aluminum foil onto the area in question. If droplets are on the side facing the room, it is condensate. If droplets are on the underside, your vapor barrier is in question. For condensate issues, use more circulation, less draperies. Try running the furnace blower all the time or a small fan blowing at the area. Most homes will get winter condensate especially when cooking, heated pots of soup, etc.