Cost & Environmental Impact

Loading the Cost Analysis Model

The first step in this tutorial is to load a model file which contains some cost and environmental impact data. The model is based on that in the Simple House tutorial. Material costs are relatively simple to input as the data is readily available to most practices. Greenhouse gas and embodied energy data on the other hand, is always difficult to find and is very location specific. In the future, however, this kind of data will become available as it is as important a design consideration as economic cost.

Important Note:

The cost and environmental data used in this example is not accurate and is used for demonstration purposes only.

  1. Open  Cost  from the Tutorial Files directory located in your main ECOTECT Install directory.

    There are three zones in this simple model, the north room, south room and ceiling space. Most of the materials in the model have been assigned cost and environmental impact values in the Material Properties dialog box.

Calculating Material Costs

  1. From the Calculate menu, select the Material Costs... item.

    Before cost analysis can be performed, some pre-processing needs to be done on the model to determine inter-zonal adjacencies. These are stored to disk in a .ADJ file with the same name as the model. If the geometry of the model has changed, ECOTECT will prompt you to recalculate these with the following message box.

  2. Click the OK button to recalculate inter-zonal adjacencies and overshadowing.

    During this calculation, objects in successive zones will highlight and small dots will appear within some of these. These dots indicate that the object is overlapped by another object on a different zone, an inter-zonal adjacency. ECOTECT uses the resulting values to determine how much of a material to apportion to each zone.

    When these calculations have finished, a blank graph will display as shown below.

  3. Click the Recalculate button.

    This will display the following fabric cost graph.

    This pie chart shows the total cost of all components as well as the relative cost of each building element.
  4. To display individual material totals, click the button.

    Whilst the graph will not change, the contents of the text list will now show a full list of all the materials used in the model along with a range of cost-related values, as shown below.

Calculating Environmental Impacts

  1. Choose the Greenhouse Gas item from the Cost Type selector and click the Recalculate button.

    A range of other energy and greenhouse related items can also be selected.

    This displays the following graph, similar to the fabric costs but with a different ratio representing the different contributions.

  2. This tutorial is intended as a quick-start guide to get you up and running. You will probably now have to update the cost data in your material library to reflect local conditions. Whilst this will at first sound a bit daunting, there are probably less that 20 base materials that your practice regularly uses. At conceptual design stage you are rarely specifying the floor tiles or surface finishes. It is therefore much easier to start off with a basic set of commonly used materials - to make sure you are at least remaining somewhere close to the budget - and then add new materials and their true costs as decisions are made during the gradual refinement of the model.