The White House is now a disaster ... by design.

1600 Pennsylvania is a construction zone ... the Oval Office empty, heavy equipment shielding the exterior ... the press room looking like a scene from "Extreme Makeover: Home Edition."

It's all part of plan to upgrade the heating and air conditioning systems, along with other improvements.

That's why President Trump got outta dodge, along with everyone else for the month of August.

After all, if it really is a swamp, you need good A.C.