Ecotect 02 | Shading (I)

SHADING CONCEPTS

Shading is an important component to energy efficient design, especially for climates which require a lot of cooling and clear sky prevails. This is because the sun is the primary source of building envelope heat gain. For other locations where there is a mix of heating and cooling needs, the goal for shading would be to prevent heat gain from direct sun in summer while allowing for passive solar heating in winter.

Example design questions that require shading analysis . .

•What is the site limitation in terms of obstruction?
•What is the optimum shading for a particular window?
•Which shading options are better for preventing direct sun?

In this tutorial, we’ll cover these topics:
- Read and understand sun path and shading mask
- Check for obstruction onto site or object
- Use shading design wizard as a starting point to design shading
- Understand parameters related to shading design and analysis


WHAT IS THE SITE/OBJECT OBSTRUCTION/OVERSHADOWING? (I)

This tutorial requires some basic knowledge of using Ecotect
Example Files: 01_site_analysis.eco



This is a blank site in residential area. The weather file now is Hong Kong, China; the weather file should come with your Ecotect package. If not, you can select any location of choice. A site is oriented with longitudinal sides facing east-west. The north icon in 3d editor view shows the orientation.

If you want to change the orientation of your model, you don’t have to rotate the whole model. Just go to Project tab and change the azimuth angle. Then, recheck in 3dEditor tab to make sure the orientation is correct.



First, we can check the overshadowing from neighbor buildings by clicking the ‘shadow range’ function under the Shadow Settings tab on the right. By selecting 3 representative days: summer solstice (Jun 21), equinox (Mar/ Sep 21), and winter solstice (Dec 21), we can check out the pattern of overshadowing throughout the year from surrounding contexts onto a site.



For example, in this setting, Ecotect will track the shadow from 12pm to 6pm, every 30 minutes.

In general, we check for overshadowing at 3 representative dates: Summer Solstice, Equinox, and Winter Solstice. You could also separate your analysis between morning and afternoon for more convenient analysis on what's happening to the site throughout the day and how to best zone the building's functional uses to fit the shading pattern.

With Ecotect, shadows from different massing layers can be toggle on/off to show the effects from different design options or before-after scenario.