I focused on the wt aspect of these cabins and got a bit of the step by step track so I'll try to go back a few steps and add some info that I think fits at the beginning of the discussion.
Back to the design ideas.
Almost any boat less than 24’ or 25’ LOA has topsides so low that most free standing walk-around cabins look too tall in those skiffs. A stand-up helm requires 6’ 2” to 6’4” of head room depending on the crew and their boots. That may sound odd but many hip boots and even Extra Toughs add nearly and 1” to your height so allowing for taller people AND an inch or so to spare gets fairly high off the deck.
Almost any small boat that has a stand-up helm also has a deck intersecting the topsides above the chine. If the cabin begins on deck which is almost always above the waterline and rises more than 6’ even skiffs with 3’ topsides look too low at the sheer. The result, in my opinion, is a cabin that ruins the looks of many an otherwise attractive small boat.
In the past, designers weren’t willing to draw boats they felt looked out of proportional or unattractive from the profile view of the hull. They’d even reduce the cabin so low you’d have to sit down inside. Perhaps more attractive and often proportionally better looking; I’m concentrating on ways of making the stand-up cabin look more aesthetically appealing not arguing the merits of a decision to have one of these style houses on you boat.
[Side Bar: One of the prettiest skiffs I’ve seen and admired for many years from a distance had a walk around cabin with forward inclined windscreens and almost perfect proportion of sheer line, cabin and cabin brow. I’d always wondered how all these elements were so finely blended into a skiff that I knew couldn’t have been 20 LOA? It wasn’t until I saw her close by that I realized the designer, owner and builder all knew exactly what we’re discussing; this cabin was only shirt pocket high off the deck! You had to duck under the roof and sit at the helm to stay in the cabin. A year or so later I saw the skipper standing at the helm, outside (!), aft the cabin bulkhead looking over that cabin
, that’s how some owners solve the problem of proportion. Still one of the finest looking welded aluminum skiffs in the Cook Inlet; she points out that not everyone NEEDS a full standing height cabin. One of the elements of this particular skiff's beauty is her fine proportions and a full ht helm would spoil that.]
If you are short, like me, you might choose to build your own boat’s cabin 5’10” as I have many times. On the other hand, taller friends don’t appreciate my selfishness when they travel with us.
The easiest way I’ve found to make the dog-house style cabin look good is by breaking the house lines at the window band/console height- about waist high. This is usually above the topsides sheer line but the break helps to reduce the overall appearance of height compared to the sheer. All of the suggested designs here will incorporate this design element to visually “shorten” the overall height and to break up the construction into more easily handled parts.
Another design element that helps is the line at the top of the cabin line and the brow or visor. Last the size of the glass panels compared to the size of the cabin sides can help to visually reduce the apparent size of the upper cabin window band and that too can help dramatically to improve looks.
Many stand-up houses feature “crabber style” (east coaster’s sometimes call this a “western cabin”) windows that lean forward instead of being plumb or leaning aft. Aft leaning windscreens in small cabins take up ‘all’ the floor area and force the helm aft while the forward leaning styles allow you to stand much closer to the front of the cabin and therefore makes possible a smaller cabin fore and aft.
Plumb or vertical windscreens are usually associated with traditional designs like tugs, work boats, push boats on older commercial fishing boats. This method of building could be used to build in that style but the examples shown in the sketches will focus on the forward inclined glass typical of the Northwest’s skiffs and work boats.
This Titan Tug image shows the traditional plumb windscreen but a fine looking brow with some curve to the side of the cabin top. This curve goes a long way to making the cabin 'sweet' to the eye. There is also a curve to the cabin break between the upper and lower parts of the main cabin. Both these curves are extra work, but are priceless in contribution to the final boat's lines.
Notice the narrow window posts? The camber to the cabin top and the line of the side turning into the brow or visor over the windows, are extra work but they sure look good to me.
Here is another little tug from the Glen-L catalog, here a smaller boat with less sheer had a PROPORTIONALLY taller house with more straight lines and less harmonious final appearance.
Maybe I'm splitting hairs, or being too picky (?), but this is an opinion piece so I'm including my reasoning for the steps ahead. I will provide the geometry and rough work methods for each of these shape lay outs and cuts, so you can adapt to your boats' sheer and overall look.