1. Home
  2. Requirements definition
  3. Making a decomposition of spaces and locations

Making a decomposition of spaces and locations

The spatial parts of your project can be defined and specified in the tree Spaces & locations.

In building projects, this tree is usually the most important part of the project as spaces typically carry most of the project’s requirements (on indoor climate, elements that need to placed etc.). Basically, you are making a room book with room data sheets.

In infrastructure projects, this tree tends to be less extensive but still highly relevant for defining the locational and geometrical aspects of the project (e.g. road segments, traffic lanes, cable corridors).

Below we’ll explain the different kinds of objects that can be used in this tree.

Don’t forget to check out our video on this topic!

Different types of objects

When creating this tree, you will be able to use different types of objects to help structure your tree:

Please note that the use of these objects is very much dependent on the nature of a project. In an infrastructure project, you will probably mostly use:

Civil structure

In a building project, you typically use:

Group of spaces
Outdoor space

See below for a short explanation of each of these object types.


This object represents the specific site, address or plot where a building or infrastructural object is located or must be realised. The object can be used to capture, for example, zoning requirements.


This objects represents an infrastructural connection between two points. This can be a high-level object such as a road connection or rail track between two locations, but also a very specific connection such as a cable corridor or a street.


A segment is a specific functional or spatial part of an connection. E.g. a traffic lane or tunnel segment. Typically segments have a concrete width or length.

Important: segments cannot be further subdivided into smaller units. This allows for the integration with BIM models in relation to the placement of spatial elements such as traffic lights, street furniture etc.  

Civil structure

This object is the spatial and/or functional representation of a built structure other than a building. E.g. a pump station, offshore platform or water treatment facility. Just like a building (see below) it can be further subdivided into spaces and groups of spaces.


This object can be used as a starting point for a breakdown of all the spaces that should be located in the same building.

Group of Spaces

This object can be used to indicate larger areas or parts of a building which can then be broken down or subdivided into individual spaces. Examples of grouping areas include departments in hospitals, the entrance area of a public building or a conference center at a campus.  


This object is the most basic unit of the project’s space tree. They are the actual volumes where user activities take place. Spaces are the most important objects of the model as they carry most of the requirements. They can have a size, capacity, particular room items, acoustic qualities, and so on.  

Important: spaces are the lowest level of the tree: they cannot be further subdivided into smaller units. This is to avoid create confusion about to which (sub)spaces requirements apply. Furthermore, it allows for the integration with BIM models.  

Outdoor Spaces

This object is essentially the same as the regular spaces above, but specifically labelled as being outdoors. Examples of outdoor spaces are parking spaces, playgrounds, and bicycle storage. Linear elements, such as foot paths or roads can also be considered outdoor spaces.

Please note: it is important to distinguish between outdoor spaces and indoor spaces in your model to make sure that the sizes of your outdoor spaces are not calculated in the total floor area of your project.

Creating objects

Go to the Spaces & locations tree and click on the at the top of the page. This will allow you to create your first spatial object. A window will pop up offering you four options to choose from (as discussed above). Once you click on one of the options and a name for the object.

When hoovering over the , you will get a short explanation about the object type

When creating and organizing the spaces for your project, it is good to know that you can easily move objects around, search for objects, rename them, delete them if necessary, and you can easily clone (copy/paste) them if you want to use the same type of space elsewhere in your break-down.

This can all be done by using the presented buttons in your screen. For a general explanation about these buttons, click here.

Structure for building projects

Typically, a spatial break-down for a building project is structured as follows:

  • You often start with a building object as the top object of your tree.
  • Next, there are likely to be one or two levels groups of spaces which can be used to cluster spaces of a particular kind (e.g. meeting spaces), or for a particular user (e.g. department A or B).
  • And, ultimately, at the lowest level there will be spaces with all the specific requirements.
  • Outdoor spaces are often located on the same level as the building, unless it concerns outdoor spaces that are part of the building (e.g. roof terrace).

Making such a break-down is also referred to as a processes of decomposition, in which you start with a top object (e.g. building), which is step-by-step, divides up until smaller parts. These parts become more concrete, more detailed and more ‘material’ as you work you way down the decomposition structure.

See for a simple example below.

Small example of a spatial break-down: the building has a conference area, and the conference area consists of a various kinds of meeting rooms, a coffee corner and a cloak room.

Please note that you do not have to make a full decomposition of your project straight-away. In the early project phases, it is often sufficient to indicate some large ‘chunks’ or groups of spaces, which can become more detailed as the project progresses. Trees can grow, so to say : – )

It can be that you want add one or more room numbers to your spaces (e.g. a functional number and, later, a geographic number) and show these in the objects’ names. This can be done by means of the classification/numbering table. How to work with this is explained here.

Structure for infrastructure projects

There are obviously many different kinds of infrastructure projects, but if we focus on ‘connections’ (a road, a rail link, tunnel, …), you spatial ‘tree’ will typically look something like this:

  • You probably start with a location object as the top object, indicating the area where the connection has to be realized and/or to indicate the actual locations that have to be connected.
  • Next, there is the connection itself , which may be subdivided into a smaller parts and/or be linked to other connections (e.g. an existing road).
  • At the lowest level of the connection’s spatial subdivision will be specific segments which typically carry concrete geometric requirements such as width or length, and can have relations to spatial elements such as traffic lights or road markings.
  • Civil structures may be added to indicate the location or geometry of building-like entities such as pump stations or water reservoirs.
Example of a decomposition of a tunnel project. Labels have been used to indicate whether a project part concerns an existing entity.

Please note that above is purely a spatial or geometric decomposition of the project. For the project’s technical decomposition (in terms of mechnical and electrical systems and construction elements), you can use the Systems & elements tree.

Was this article helpful?

Need Support?
Can't find the answer you're looking for? Don't worry we're here to help!