AC is inadequate to remove basement humidity. As soon as the house is closed in, during summer months we run an adequate capacity dehumidifier. But don't expect a tract builder to be doing that!

Thank you for your responses. My builder said it is common to have surface mold during construction. He states that spraying bleach and ac will fix the issues. What do you all think of this? It’s everywhere on our dry walls and cabinets too.

Some amount of mold and mildew should be expected on lumber in a stick-built home which is exposed to the weather throughout the rough framing. Once the home is "dried in" it's a matter of getting the moisture content of the framing to a level that won't support mold/mildew growth. Some builders accelerate the drying process with industrial type dehumidifiers.

A home should be sufficiently dry to preclude mold and mildew growth on the drywall. The HVAC system should be operational before installing interior trim, hardwood flooring and cabinetry. I would not expect to see mold/mildew on any of those.

Basements are problematic. First, water is an ingredient in mortar and concrete which cure over time and release moisture. Second, basements tend not to call for air conditioning and thus get no dehumidification unless a dedicated dehumidifier is installed as Worthy noted above.

The mold and mildew on what appears from your photos to be a cabinet interior would be a concern to me.

Thank you for your responses. My builder said it is common to have surface mold during construction. He states that spraying bleach and ac will fix the issues. What do you all think of this?no it all has mold :(

I think your builder is blowing smoke, er, make that mold spores. It is not common, in my experience, to have active mold growth during construction once a structure is dried in.

The last thing I want to do is to apply a bleach solution to wood cabinets, unpainted drywall or the like.

You have a mold problem that needs proper investigation to determine the root cause. Once the root cause is determined, modifications to the existing construction or HVAC system may be needed to prevent a recurrence.

If it's all over, I think you have a problem. Bleach and AC may remove it temporarily but it will most likely come back. You need to find out what's causing it.

It's fairly common to see some mold in a new construction basement before the AC or HVAC is running, since new materials like concrete and drywall release a lot of moisture and there’s no humidity control yet. If it’s just a light surface film, it often improves once the home is conditioned and humidity is kept below about 50–60%, though you should still clean the affected areas. But if there’s widespread growth, strong musty odors, or mold on finished materials like drywall or insulation, it won’t just go away on its own and should be addressed now. In the meantime, check for any leaks or drainage issues, use a dehumidifier if you can, and notify the builder so it’s documented and properly handled.