Let D denote the open
unit disc in the complex plane and f = h +ḡ a complex-valued, harmonic,
univalent and orientation preserving map in D, where h and g are analytic in D.
We show that g,h ∈ Hλ and f ∈ hλ for some λ > 0, where Hλ(hλ) is the
Hardy space of order λ for analytic (harmonic) functions. We also study the
correspondence under f between ∂D (boundary of D) and the prime ends of
f(D).