The diagrams above show that the precipitation in Kathmandu is high both in the winter and in the summer, and that the mean value of temperature in the winter is around 14 degrees. Because of the high humidity the building should be ventilated to minimize moisture damage such as mold. Therefore one should increase heat gain in the winter through radiation so the walls can dry when the sun is up. This will also improve the temperature inside the building. On the contrary, in the summer it the windows should be shaded to reduce overheating. Because of the high humidity during summer, one should design the building to increase heat loss through ventilation.
In regards to the monsoon rains, the envelope of the building has to be water proof and also has the ability to transport moist from the inside and out in the warm humid summer, in other words it has to breathe. The roof overhang will help to protect the walls envelope and with an inclined roof transport the water away from the façade. It is also important to consider how to transport the water away from the building’s foundation. In Kathmandu this happens naturally as it is in a hillside.
The small difference in average dry bulb temperature makes it easier to construct a building that can exploit the sun for heating in the winter and shade it in the summer. Traditionally, to prevent overheating one can optimize the roof overhang and the size of the windows regarding the sun’s position. In the summer the sun will be higher in the sky and therefore will the roof overhang have a shading effect. Furthermore, the position of the windows and the length of the building facing the sun is also a parameter that should be taking into consideration.
Chapter 3: New buildings in the areas
In the vernacular architecture, buildings were created using all the materials that were present near the construction site. Nowadays it is simpler to transport materials from far away, and it is important because of the improvement of the building techniques and the reaction of the building to the environment. The development of the construction is a response to reduce the life costs and to give better living conditions to the people host inside.
Through history, there have been different needs: before the year 2000 was a common idea to have a good building, but without thinking about the energy consumes and the impact on the environment. Now we have some conditions that induce us to design buildings that use less energy as possible, trying to reach a balance of zero (Net Zero Energy Buildings).
Rome
Rome is the capital city of Italy; its story allows us to understand that it is a very big city and heavy populated. The constructions density is very high and all the buildings are almost old buildings. The new constructions are only a few, but sometimes it is possible to find requalified buildings that goes from low efficiency to high efficiency category. One of the most important constructions of our study area is the residential building placed in Via Giarre in Rome, Borghesiana zone. It was a residential building made by three flats, one each floor and independent from each other. The requalification has implemented this building, improving the internal spaces, energy efficiency and the external aspect.