The most likely cause is that the floor was laid without leaving a space or void along the wall to allow for expansion and contraction. This can be corrected by removing the baseboard and cutting the floor back about 1/4" to 3/8". The only other common cause would be if it got very wet in that area at one time and warped.

If the individual boards are warping it's not because of a lack of expansion room around the edges. More likely the floor got wet on top after the boards were laid and the top expanded relative to the bottom, resulting in the bowed-up appearance. If you're extremely lucky the boards will even out on their own as the moisture level reaches an equilibrium. If they're still curved after a few months you might have to sand them down to get a flat surface.

We bought a newly renovated condo with all new oakwood floor. The east side of the condo floor (including kitchen and second bedroom) start to crown. The mid section of the plank is about 0.5 cm higher than the edges. The crowning is obvious when you look close. But the floor still looks quite nice.

The west side of the floors are flat.

Should we do something about it or this is what we have to live with hardwood floor?