Judged from the artwork of the housebook of castle Wolfegg and related work there seem to be two options for a man who wants to be dressed properly. Over the obligatory doublet with attached hose, either a short cape or a usually equally short gown can be worn.
The gowns in the following pictures are all rather short, just covering the behind. At waist level, they appear to be gathered into folds. These folds might be fixed, but they could also be simply and neatly gathered by a belt around the waist (see the black belt in picture 1 and the paragraph below). The type of sleeves can vary, in the first two pictures they are long, wide and folded back at the wrist, while the sleeve in the third picture appears much more fitted. Picture 4 shows that the sleeve seam runs along the back of the arm, as it is typical for late medieval tailoring. It would also appear that (some of) these gowns have a collar, the two pieces meet in a triangular fashion in the back (picture 1, 3 and 4).
The front of the gown is open, the two sides are held together by the belt at waist level (most obvious in picture 3, which shows the right side of the gown folded across the left) and a thick lacing cord across the chest (picture 1, 2 and 3). The pictures below also show more elaborate gowns made from patterned (brocade?) cloth (picture 1), with the frequently observed 'attached-leaf' style (picture 2, possible these are leaf-shaped cut-outs in a non-fringe fabric?), or gashes in the front (picture 3) and/or at the shoulders (picture 3 and 4).
The following three pictures show gowns worn loosely without a belt, that show that the folds of these gowns are not fixed at waist level. Additionally, the first picture clearly shows both the collar of the green gown and the grey collar of the doublet beneath.
May 05, 2010: I'm using thick, greyish-blue wool for the gown that was fortunately left over from a coat I have
made ages ago... The gown is lined with light-weight, light grey wool-silk-mix (the colors match quite well and wont clash with the
doublet or hose).
The sleeves will be rather wide and long enough to be folded back at the wrist. The pattern is really simple. As you can see below, I've simply added flare below the (slightly widened) armholes. The lenght of the gown is 75 cm with an approximate hem with of 50 cm for each front and back piece. Both the gown and even the sleeves fit on the first trial (not what I became used too after the housebook doublet and my grande assiette sleeves...). Although there is no curving in the center of the back pieces and thus a seam would not be strictly necessary (giving the width of modern fabric, at least), I'm cutting the back in two pieces as the pictures above clearly show a back seam.
Making up was equally fast, having started with the gown on May 01, by now I've already sewed all the pieces together (all visible seams on the inside and outside are sewn by hand, as usual). What's left to do? Only four eyelets and the cord for lacing the gown in the front...
June 21, 2010: The finished gown
Finally, some pictures of the finished gown (worn over the Housebook doublet)... I made a thick, two-coloured woolen lace (8 loops) for the front of the gown. As I've not yet found points that are large enough for the lace, I've simply knotted the ends (as seen above in the first image of the second row of pictures).