ARCHITECTURAL TECHNOLOGY Exercise 2 - Materials & Energy in Dwellings
KEITH CHAN WSA2
AIMS
In this investigation I am to explore the variation of energy demands over the year and its annual energy use. I will pinpoint where the main energy demands and losses appear to be coming from and, from an architect’s point of view, what elements we can control.
METHODOLOGY USED At first I am drawing a rough massing model in ECOTECT, which would include all the surrounding masses. The site model would have the correct orientation and the masses would have the correct sizes and building heights so that physically we can model the correct overshadowing and comment on solar access.
SUNLIGHT & SHADOW DAILY ANALYSIS
The image on the top at the centre is the model I have produced, the highlighted unit is the mass that my dwellings will be positioned. The materials are also assigned for each elements in the building. I will focus on one unit to produce the analysis. It will be the flat unit on the southern edge of the L-shaped mass,
SUNLIGHT SOLAR ACCESS & OVERSHADOWING
To gather more insight into the energy use of the site we need to first explore the surrounding context concerning solar exposure. The centre column is the sequence of sunlight shadow variations in a few hours interval within the day. As you can see in the morning till around 3pm in the afternoon, the proposed unit receive most sunlight without overshadowing, however from about 4pm onwards the units starts to be overshadowed by the surrounding building mass in the west. Analysing the units with problems of overshadowing can also let architects to orientate buildings and design the openings to a building. It can also give us an idea how much surface of the building is in direct contact with solar radiation. Heating a dwelling to comfortable standard needs energy and sunlight is the only natural renewable energy source that we could rely on during the day.
MATERIALS
The tables of figures on the far right describes the materials I have assigned for my dwelling unit. There is also the detailed section of how the layers are compiled together, it was important to deal with which elements were placed in the order from “outside” to the “inside”, the waterproofing consideration, rigidity of the materials and also the conductivity of the materials. The lower the conductivity each component has the lower U-values the building element would be overall. The materials assigned all comply to the minimum fabric requirements of requirements of the new Part L 2010, in particular the U-values which is the overall heat transfer coefficient, which describes how well a building elements conduct heat. WALLS - the unit built will be of concrete and plaster applied on either side. A thick layer of insulation is inserted (Preformed Fibreboard) and thicker concrete walls were in place to bring the U-value down. FLOOR - Since my unit is placed on the third floor, it has a different composition of material layers compared to units on the ground. This time I included the plaster ceiling tiles from the unit underneath, and the concrete flooring along with insulation layer and timber flooring on top. Windows - I had to apply triple glazing to meet the U-values in Part L Regulation. This is because I had to have 2 layers of air gap in order to achieve the relatively low U-value while using standard glass which is inconveniently very conductive. ROOF - The units are all under one flat roof. A thick layer of the traditionally used rock wool is inserted for insulation and thick concrete layer is also giving waterproofing along with insulation and structural function.
Image on the right shows the shadow range of the units which highlights the awareness of certain areas with overshadowing of surrounding buildings. The unit highlight in yellow is the dwelling unit that I am investigating and analyse.