original building form
the recommended building form based on your evaluation and analysis
In this module, we are changing the height and rotation angles of the building to find the best design case that may maximise the solar insolation potential and minimise the surface area of the building envelope and the projected construction cost.
In our model, we calculate the total amount of solar radiation based on the amount of solar radiation received on our panelised building surface during the whole year and take the average value. In this case, the amount of solar insolation for our building is given in units of energy per area per year. In order to achieve this goal, we created a sun model based on our location in San Francisco and used it to simulate the total amount of solar insolation the building will get on average for each year. One note here is that we are only accounting for the direct radiation from the sun, which is measured perpendicular to the sun’s rays, but we are not taking diffuse radiation into account, which is both scattered by the clouds and atmosphere and the ground in front of the surface, and is always measured on a horizontal surface.
When calculating the approximate building cost, we are using the area of each floor multiplied by the unit cost of each floor. We assumed that when building the higher level of the building, the cost of a unit area space will also increase.
We get the output table shown below after evaluating 158 different cases using different building heights and rotation angles. As we can see from these results when comparing the building of the same height but with different roof rotation angles, the solar insolation gets higher when the angle is between 45 and 90 degrees. However, the estimated total floor area and construction cost do not change much when the rotation angle changes when the building heights are the same. When looking at the buildings of the same rotation angles but with different heights, their solar insolation increases rapidly when the building height increases, although the cost may only increase slightly.
When evaluating my results for the surface area, cost, and solar insolation, I weighted the potential solar insolation the most. When conducting a passive solar design, solar radiation is always one of the most important factors since it is directly related to the building’s energy efficiency. The sun is not only providing us with daylight, but we can also use the sun’s energy for the heating and cooling of living spaces.
Thus, my top 3 recommended design alternatives will be when the building is relatively higher but with a 45 to 90 rotation angle. The first one will be a building which is 136-metre high and has a rotation angle of 90 degrees; the second one would be a building with a 125-metre height and also a 90-degree rotation angle; while the last one would be a building with a 148-metre height and a 77-degree rotation angle building, which would also be the one that I would consider as my best choice.
