Everything depicted on a floor plan is usually either horizontal (like floors or fill areas) or vertical (like walls). The former are seen in all their glory - the shape of the objects is of prime importance, and the vertical aspect less so - the thickness of a floor is controlled by one number, the elevation by another). Vertical components are a bit harder - walls, for example, have shapes, but they cannot be seen in the plan; all that can be seen is the projection of their thickness.
Roofs are middle ground. They are somewhere between flat and upright In plans they are, by necessary, shown flat, but that is just a convention. It is useful, because it easily shows the relationship of roof edges to walls, which is important, but the verticality of a roof is lost in the plan.
Punch! depicts a roof by its projection onto a plane, as if looking down upon it. That's conventional and correct, as mentioned above. Punch! also provides measurements around the edges, and with that there are problems, because the lengths don't measure anything real when the edge measured differs in height from one end to the other. For example, a roof panel that is 10'x10' in size, when pitched along one edge to 12:12 (45 degree angle) has a horizontal projection of just a bit over 7'. Alternatively, a Punch! roof angled the same way, appearing to be 10'x10' in the plan, is actually 10'x14.4' when measured. This might be considered trivial, except that the mis-measurement affects the estimator (it orders rafters that are 4.4 ft too short), and the area computed for shingling and insulation is likewise shortened by 40%.
While PlansPlus cannot do anything about the Framer and Estimator, it can at least make the measurements correct in the plans. The option to do that is shown here:
The default value is Selected [Punch! Normal] Measurements, and the plans it produces have the same measurements as Punch! does. The alternative, Foreshortened Perspective Measurements, changes the measurements shown for edges of book roofs and roof panels to account for the diagonal measurement along the roof edge, rather than its projection on the plan plane. So a 10'x10' panel wil have measurements displayed of 10'x10', rather than the Punch! values of 10'x7'2".
With version 10.0, Punch! has introduced a couple of "roof attachments", a generic roof hole (like the floor cutout for floors) and the skylight. Neither of these show measurements in the plan, so they don't have to have adjustments like the roof edges do. The roof hole is designed to allow accommodation in a roof for a dormer, and the horizontal projection of that hole works just fine for the purposes of the hole, so it is not affected by the roof selection. The skylight, however, is another story...
The skylight, rather than being drawn freehand on the roof, is placed and then the shape and size are selected as skylight properties, and the outline drawing on the plan is made to those measurements and shape. The skylight may also be designed like a window using the custom window designer, which also supplies the skylights measurements. When you specify 4' tall skylight and place it on the roof, a 4' scaled rectangle is drawn to represent the skylight. The problem is that the rectangle should be drawn foreshortened (that is, shrunk in the direction of the roof's down arrow) in order to correctly display how it works on the roof. A foreshortened rectangle can fit where the full sized one wouldn't, in one example of the problem.
So, in addition to setting the roof measurements properly when the roof foreshortening option is selected, the shapes of the skylights are also correctly displayed. The Punch! outline is displayed in a light gray, and the true, projected outline of the skylight is displayed in the roofing blue color. A pair of skylights in the picture above are displayed, one for a rectangular window at an odd angle and the other a circular skylight. The dark outline shows how the skylight would look if you could look straight downwards in LiveView from above the roof.
PlansPlus and the contents of this help file are
Copyright©2006 by ThistleKeep Engineering; all rights are reserved.
Comments and suggestions, as well as support, are entertained at Lmc@ThistleKeep.com.
"Punch!" and other titles of Punch! operations are trademarks of Punch! Software L.L.C.