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Es_3 Concept Design Analysis (Viale di Trastevere) - Laboratorio Montuori - Arianna Conte, Massimiliano De Crignis
The project is located near the Trastevere railway station in Rome. In a site that have a difference in height of 6-7 meters in total. There is no slope, but a sudden gap that makes designing a bulding in this area a difficult task. This peculiar morphology is a result of the proximity of the Gianicolo hill, to the west of Viale di Trastevere, and a depression created by the Tevere river to the east of the area.
(thanks to the colleagues of LAB 6A for the modern aerial view picture)
The sudden gap in altitude, instead of a natural slope, was artificially made to contain the old railway that in the past was in place of the road that is Viale di Trastevere today. The railway was removed with the passing years, but the containing wall was preserved untill few years ago, when began the construction of a parking building that sits on the site that we are going to use for our project.
Given the complexity of the lot, it was given the opportunity to concentrate the project in one of two distinct parts (red and blue perimeter). We chose the red perimeter that has an area of 1800 mq.
For our analysis we started following the steps of our first two assignment. We selected the location, importeted the site image and modelled the area, including the nearest buildings and the difference in altitude with contour lines. This time we modelled the different entities giving them different names in the Project Browser window. As such we modelled the terrain as singular entity and gave it the name "terreno". We did the same thing for the bulidings, giving them different names.
Then, we proceeded to model different concepts for our project to evaluate how choosing a different kinds of tipologies for our bulding can drastically modify its energetic behaviour.
Concept 1: Vertical and Horizontal Towers
Fot the first concept we made a system of towers and horizontal elements, with an arrangement of residences and services undifferentiated between the higher and the lower floors (it is yet to be decided specifically). After having modelled the concept we rearranged the levels of the 3D View to correspond them to the different floors of our building and renamed them with the height and description of the levels.
For this concept we considered some underground floors, so it was necessary to create a -4.00 level.
After that, we selected the mass of our project and clicked on the "Mass Floor" command under the "Modify | Mass" tab. We selected the levels that we wanted to intersect our bulding with.
This procces of renaming and rearranging levels, and then intersecting them with our building let us create a series of schedules with which we can easily and parametrically control and modify the status of our design. To create a schedule we selected the "Schedule" options under the "Menage" tab. In the "New Schedule" window we selected "Mass" as category and then selected "OK". This is the window that opens up after that:
In which we can select the fields to schedule for our project.
We added custom parameters too, using the option "Calculated Value" shown in the previous pitcure. This command lets us insert in the schedule different types of field that are not in the "Avaiable fields" list. For example we created the column named "Surface-to-Volume Ratio" by using the formula: 1/(Gross Volume/Gross Surface Area). This is a very important value that represent the ratio between the disperding surface of the building and its gross volume. The legislation says that it constitutes (with the Degree Days) the maximum quantity of dispertion expressed in kWh/mq/a of the residential building.
Shadow analysis
We proceeded, like in the first assignment, to analyze the shadows that the surrounding buildings cast on our project and viceversa. To do that, we selected two extreme situations in the course of the year (the winter and summer solstice) and analyzed the casted shadows at 9:00 AM, 12:00 PM and 15:00 PM.
Winter solstice - 9.00 AM
Being a system of towers, our project is only partially darkened by the neighbour buildings because of its taller height. Infact, without considering the small portion of the 3 floors section darkened, it is the building itself that cast a shadow on its parts thanks to its complex typology. The taller tower is partially in the shadow of the smaller tower in front of it and its orizzontal continuation. This problem could be resolved by setting farther the smaller tower from the bigger one. We can see how the courtyard created by the building is completelly shaded at this hour.
Winter solstice - 12.00 PM
Thanks to its slight rotation to east that follows the morphology of the gap. The two smaller tower and the "orizontal" tower have solar radiation hitting two facades: the ones facing south-east and south-west. The bigger tower is still shaded by the other section of the building. The courtyard is still shaded too.
Winter solstice - 3.00 PM
The south facade of the bigger tower is finally almost completelly in the sun. We can see how our building is casting a shadow on the building at north-east, which is not residential. The gap of 7 meters doesn't come to our favor here, because it completelly darkens the courtyard. Which, at this point, results completelly in the dark for the entire day. It is important to notice though that this is an analysis that covers only 21/12, the shortest day of the year. For a more complete analysis is necessary to do a solar radiation analysis lasting the entire winter period.
Summer solstice - 9.00 AM
Like in the winter case, the building cast a shadow on itself, but only for a very small portion. The neighbour building casts a very little shadow on the lowest part of our project because of the higher sun path which results in shorter shadows.
Summer solstice - 12:00 PM
The eleveted L block continues to cast a shadow on the elevators tower. Unfortunately that's the only considerable shadow casted on the building.
Summer solstice - 15:00 PM
The L shaped block at this hour casts a bigger shadow on the west facade of the east tower, this means that during summer at noon hours that facade could be less irradiated thanks to the long protrusion above it.
Cumulative analysis
Winter: from 1/11/2013 to 28/2/2014 (7:00 AM - 5:00 PM)
South-west view
As the shadow analysis suggested, the bigger tower south facade is only half well irradiated, this is caused by the vicinity of the large L shaped elevated block that casts a shadow on the lower part of the facade for most of the day. The smaller east tower has the same results but because of the neighbour building's shadow. Thanks to the rotation of the elevated L block, its west facade receives more radiation than it could if it was oriented like the bigger tower.
North-east view
The courtyard doesn't show to be receiving much solar radiation at all. This means that if the typology of the project should remain as it is, that place will not have grass areas, but maybe evergreen or tall trees.
Summer: from 1/6/2014 to 15/09/2014 (7:00 AM - 6:00 PM)
South-west view
Except for the east smaller tower's west facade, which is shaded by the elevated L shaped block, most of the building facades appear to be well irradiated during the entire summer period. The rotation of part of the building in this istance is a negative point as can be seen comparing the colours of the bigger tower with the colours of the smaller south tower and the elevated L block. Every facade from red and up will necessitate of adeguate shading systems.
North-east view
Having horizontal ceilings, those are the place where will be the most solar radiation in summer. To resolve that we could suppose either the presence of a green roof or maybe to have slopes instead of horizontal roofs.
Concept 2: Linear Building with a Hole
The second concept is a linear building that folds following the morphology of the gap, with a big hole in it. Services will be placed mainly on the first two floors (the ones starting from 0.00) while the residences will be placed mainly on the upper floors.
We can see how this concept has a way lower Surface-to-Volume Ratio. That's because the building is much more simplier than concept 1, thus there is less disperding surfaces compared to the gross volume of the building. It's important to say that while the first concept couldn't benefit much heat gains from the attached L shaped building, in this case where there are many less disperding facades, having even one disperding facade less can make a difference in thermal behaviour, especially in winter.
Shadow analysis
Winter solstice - 9.00 AM
Contrary to concept 1, this building isn't really that much taller than the neighbour buildings, and the structure is pretty simple. This means that our building doesn't cast shadows on itself and that neighbour building's shadows have a major impact on our concept. In this istance, the lower floors of the east facade are partially shaded.
Winter solstice - 12.00 PM
The facade that is best oriented is the south one, but it's a pretty small surface compared to the rest of the building. In this picture we can see how the west facades at midday have yet to receive full solar radiation. Moreover the big opening of the building create a considerable shadow on the othe south facade of the building.
Winter solstice - 15.00 PM
Finally the west facades are fully irradiated, but not for long since it's 21/12 (it's sunset at 4:39 PM)
Summer solstice - 9.00 AM
There is not much to say here that has not already been said in this post and in the previous assignment. The east facades receives most of the solar radiation for the first part of the day.
Summer solstice - 12.00 PM
We can notice how the hole in the building let it create a shadow on the inner south facade that covers its entire height. Considering that it's summer that could be pretty nice for residences collocated there. On the contrary, on the outer south facade is neccessary to put shading system to prevent solar radiation in trough windows.
Summer solstice - 15.00 PM
Focusing on the inner south facade again we can see how the facade is completelly in shade now. That is because of the rotation of that section of the building that follows the morphology of the gap. We could argue, looking at this picture and the previous one, that this facade needs no shading system at all thanks to the typology of the building itself. To know if that's true we should look at the cumulative analysis during the summer period.
Cumulative analysis
Winter: from 1/11/2013 to 28/2/2014 (7:00 AM - 5:00 PM)
South-west view
As expected, the outer south facade receives the maximum solar radiation, but considering that it's only a really smal portion of the entire surface of the building we can conclude that this is not a really good orientation and typology for the winter period.
North-east view
We can see how the bending of the building causes even less radiation on the last part of the east facade, confirming the verdict that this typology in this site doesn't work very well during winter.
Summer: from 1/6/2014 to 15/09/2014 (7:00 AM - 6:00 PM)
South-west view
This picture confirms what was stated previously, the inner south facade receives very little solar radiation in summer. That let us have total freedom on the design of that facade without worrying about shading the windows properly.
North-east view
Conclusion
The concept 1 has the advantage of having more surfaces facing south, which means having warmer residences in winter, a courtyard which is not very sunny tough, the presence of services underground which benefit heat gains in winter and heat loss in summer and a more interesting typology in general.
The concept 2 has the advantage of having the inner south facade complettely shaded in summer without shading systems, a bigger roof which we could use maybe as a garden and the lower Surface-to-Volume ratio.
We believe that with the proper adjustements the better solution for this site is the concept 1.