  We model the Class I source L1551 IRS 5, adopting a flattened infalling
envelope surrounding a binary disk system and a circumbinary disk. With our
composite model, we calculate self-consistently the spectral energy
distribution of each component of the L1551 IRS 5 system, using additional
constraints from recent observations by ISO, the water ice feature from
observations with SpeX, the SCUBA extended spatial brightness distribution at
sub-mm wavelengths, and the VLA spatial intensity distributions at 7 mm of the
binary disks. We analyze the sensitivity of our results to the various
parameters involved. Our results show that a flattened envelope collapse model
is required to explain simultaneously the large scale fluxes and the water ice
and silicate features. On the other hand, we find that the circumstellar disks
are optically thick in the millimeter range and are inclined so that their
outer parts hide the emission along the line of sight from their inner parts.
We also find that these disks have lower mass accretion rates than the infall
rate of the envelope.
