# Canopy Areas

With the "Canopy Areas" function, each layer of a roof surface can be divided into multiple areas. The following areas are distinguished:

* Canopy area
* finished area
* unfinished area

The division of a layer into these areas depends on various criteria:

* The layer must have the switch 'Formwork surface', 'Insulation surface' or 'Surface measurement' in the variant to which it belongs.
* Unfinished areas arise when the corresponding roof surface lies wholly or partially above a 'boundary slab'.

Layers with formwork are often divided differently than the other layers; for example, the canopy area and the finished area may be covered by the same formwork. The terms 'canopy area' etc. are then no longer appropriate, which is why we refer to formwork areas for the formwork layer; up to three formwork areas are distinguished. Often formwork area 1 is the visible formwork, formwork area 2 the rough formwork and formwork area 3 an unformed area. However, other formworks or panels may also be present in the formwork areas, which is why we simply speak of formwork areas. For the formwork areas, the determined canopy, finished and unfinished areas are adopted and optionally aggregated.

For determining the canopy areas, a base polygon is entered. This base polygon can be created manually or by adopting the building outline or the walls. The base polygon can be offset by an overhang relative to the adopted or entered contour.

Additional overhangs can be set for the formwork layer. The canopy boundaries of the formwork layer are shifted by these after the base polygon has been transferred to the formwork layer. This allows different overhangs of the formwork boards at verge and eaves to be taken into account.

Starting from the base polygon, the boundaries of the canopy areas are transferred to the other layers according to the following scheme:

* The base polygon belongs to a building outline. It is transferred only to the roof surfaces of that building outline. This makes it possible, for interlocking roofs, to enter separate base polygons for each building outline that do not interfere with the roof surfaces of the other building outlines.
* In the roof surface variant, a layer is set as a 'kink layer for surface areas'. The base polygon is projected perpendicularly onto the kink layer and the layers below it. The roof areas outside the base polygon are then determined as canopy areas, and the roof areas inside as finished areas.
* On the layers above the kink layer, the boundaries of the canopy areas are transferred perpendicular to the roof surface.
* Thereafter, some analyses follow that extend the canopy areas according to construction rules. As a result, it is sufficient to adopt the base polygon from the building outline and you still obtain, for example, canopy areas in a transverse building with a higher eave, even if these do not lie outside the base polygon.
* The analyses for the structural extension of the canopy areas in particular search for tile layers. If the tile layer of another roof surface (e.g. main roof with a lower eave) lies beneath a roof surface (e.g. of a transverse building), the overlying roof surface receives a canopy area. This also occurs if this canopy area lies within the base polygon of the canopy areas. However, this behavior can be switched (see below).

The separation between finished and unfinished area is effected by boundary slabs. If a slab has been entered as a 'boundary slab', it automatically separates the two roof areas. This separation takes place at the top side of the topmost insulation layer of the slab. Where the top side of this layer terminates in the roof surface, finished and unfinished areas are separated. This separation is then transferred perpendicularly upward to all corresponding layers.

If desired, the canopy, finished and unfinished areas are aggregated at the end for the formwork areas of the formwork layer.

For clarification, see the sketch below:

<figure><img src="https://1294550180-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0t0AJ2HDudwBgiGFR59Q%2Fuploads%2FHdPJP3bkwjMXYT6gS8Ef%2Fgrafik.png?alt=media&#x26;token=0b6a3aab-6ea7-40a7-95db-ce244d75c4ad" alt=""><figcaption></figcaption></figure>

### Roof execution:

<table><thead><tr><th width="62" align="right">Position</th><th width="86.316650390625" align="center">Core layer</th><th width="81" align="center">Insulation</th><th width="88" align="center">Formwork</th><th width="82" align="center">Tiles</th><th width="92" align="center">Kink layer</th><th width="159" align="center">Boundary ceiling runs up to</th></tr></thead><tbody><tr><td align="right">-5</td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center">X</td><td align="center"></td><td align="center"></td></tr><tr><td align="right">-4</td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center">X</td><td align="center"></td><td align="center"></td></tr><tr><td align="right">-3</td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td></tr><tr><td align="right">-2</td><td align="center"></td><td align="center">X</td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td></tr><tr><td align="right">-1</td><td align="center">X</td><td align="center"></td><td align="center">X</td><td align="center"></td><td align="center">X</td><td align="center">X</td></tr><tr><td align="right">0</td><td align="center">X</td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td></tr><tr><td align="right">1</td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td><td align="center"></td></tr></tbody></table>

### Ceiling execution, boundary ceiling:

<table><thead><tr><th width="62" align="right">Position</th><th width="86" align="center">Core layer</th><th width="100" align="center">Insulation</th></tr></thead><tbody><tr><td align="right">-3</td><td align="center"></td><td align="center"></td></tr><tr><td align="right">-2</td><td align="center"></td><td align="center">X</td></tr><tr><td align="right">-1</td><td align="center">X</td><td align="center"></td></tr><tr><td align="right">0</td><td align="center">X</td><td align="center"></td></tr><tr><td align="right">1</td><td align="center"></td><td align="center"></td></tr></tbody></table>

### Notes on the graphic:

* Tile layers do not receive roof areas
* The formwork layer (-1) has been given an additional overhang for the canopy area (see below)
* The core layer 0 of the roof and the core layers and shells of the slab located above it intersect.
* The lower shell (1) of the roof terminates at the core layer of the slab
* The lower shell (1) of the slab terminates at the lowest shell of the roof
* The finished area ends at the top side of the insulation layer (-2) of the slab

The following settings can be made for determining the roof areas:

**Overhang formwork layer**: For the line types 'eaves', 'rising eaves', 'verge', 'slanted verge' and 'upper shed termination' you can enter a dedicated overhang specifically for the formwork layer. The canopy boundaries of the formwork layer are shifted by this after the base polygon has been transferred to the formwork layer.

**Formwork areas**: For each formwork area it can be specified which of the areas canopy, finished and unfinished should be aggregated. Only an ascending, contiguous and unambiguous assignment is possible, which is controlled by the dialog box itself. If you want to assign an area differently, you can only click on white, empty checkboxes; if a checkbox is already checked, clicking again will clear the check and all possible entries will be freed.

**Calculate canopy over tile layer**: With this setting it can be influenced whether tile layers of other roof surfaces below the considered roof surface should be searched for:

> **All:** With the 'All' option, tile layers below the considered roof surface are searched for and canopy areas are generated where applicable. In this analysis all roof surfaces are taken into account, regardless of which building outline they belong to.
>
> **current building outline**: With this option tile layers below the current roof surface are also searched for. However, only the roof surfaces that belong to the same building outline as the roof surface that is to receive canopy areas are considered.
>
> **None**: The search for tile layers below the current roof surface is omitted.

**Canopy base polygon -- overhang**: Here an overhang is entered by which the base polygon for the surface areas should extend beyond the line that will later be defined using the functions 'Input', 'Building outline' or 'Wall adoption'. (Similar to the overhang when entering slab fields.)

**Wall takeover**: For wall adoption you enter the storey and the reference line from that storey. The reference line can be chosen as 'outer contour', 'reference axis' or 'inner contour'.

**Minimum width of canopy areas**: If areas are created during automatic determination of the canopy areas that are narrower than the width entered here, that area will be deleted.

With the 'Input' switch a base polygon can be entered manually. All input and snapping functions are available. With the 'Building outline' switch the building outline is adopted as the base polygon. With the 'Wall adoption' switch the reference line of the exterior walls entered above is adopted as the base polygon.
