.. index::
   single: Sites
   single: Civil Sites
   single: Topology container

Sites
=====

A **site** is a named container for civil objects that share a topology —
Civil 3D's own organising concept, and compatible with it.  A site is not
drawn: it has no geometry, no style and no layer.  It exists so that parcels,
grading groups and alignments can be grouped by the piece of ground they
belong to, and listed that way in the Prospector.

Membership rules:

.. list-table::
   :header-rows: 1
   :widths: 26 74

   * - Object
     - Site membership
   * - **Parcels**
     - Always belong to a site.  A parcel added without one is stamped with
       the default site, ``Site 1``.
   * - **Grading groups**
     - Always belong to a site, with the same default.
   * - **Alignments**
     - **Optional.**  An alignment with no site stays in the top-level
       *Alignments* collection, which is where a road centreline normally
       belongs.  Put an alignment in a site when it is part of that site's
       layout — a subdivision access road that defines parcel frontages, for
       instance.
   * - **Surfaces, points, corridors**
     - Not site members.  They live in their own top-level collections.

.. index::
   single: Sites in the Prospector

Sites in the Prospector
-----------------------

The Prospector's **Sites** node lists every site in the drawing, with the
count in brackets.  Expanding a site shows four folders, each with its own
count:

- **Alignments** — the alignments assigned to this site, each with its
  element count and length.
- **Feature Lines** — reserved; feature lines are not yet site members.
- **Grading Groups** — the gradings in this site, with cut, fill and net
  volumes, or ``[stale]`` when a rebuild is pending.
- **Parcels** — the parcels in this site, with their areas.

Sites with nothing in them are still listed, so a site created ahead of the
work it will hold does not disappear.

.. index::
   single: Creating a Site

Creating a Site
---------------

Right-click the **Sites** node (or any site under it) and choose
**Create Site…**, then type a name.  Names are compared case-insensitively,
so ``Phase 1`` and ``phase 1`` are the same site; creating a name that already
exists simply selects it.

Sites are also created implicitly:

- Adding a parcel or grading with no site creates ``Site 1`` if it is not
  there already.
- Opening a drawing that names sites — an IQcad ``.iqz`` or a Civil 3D DWG —
  creates each one as it is read.

.. index::
   single: Moving an object to a site

Assigning an Alignment to a Site
--------------------------------

Right-click an alignment in the Prospector and choose **Move to Site…**.  The
dialog lists ``<none>`` plus every site in the drawing; ``<none>`` returns the
alignment to the top-level *Alignments* collection.  Typing a name that does
not exist yet creates that site.

The tree refreshes immediately and the drawing is marked modified.

.. note::

   Site membership is **membership only**.  Unlike Civil 3D, assigning an
   alignment to a site does not subdivide the parcels it crosses, and moving
   an object between sites never changes its geometry.

.. index::
   single: Sites in file formats

Sites in the File Formats
-------------------------

.. list-table::
   :header-rows: 1
   :widths: 22 78

   * - Format
     - Behaviour
   * - **IQML** (``.iqz``)
     - The site list is written with its names and descriptions, and each
       parcel, grading and alignment carries its ``siteName``.
   * - **DWG**
     - Civil 3D sites are read back with the objects that belong to them.
       Writing sites out as Civil 3D objects requires the **Civil 3D objects**
       survey-export mode — see
       :doc:`/parts/cad_environment/14_dwg`.
   * - **LandXML**
     - Sites are not part of the LandXML schema; parcels and alignments
       export without their membership.