Now that were all more “green” conscious, I noticed that Architects tend to use more passive strategies on their design, which is a brilliant concept, especially using materials that have a good thermal insulation. A problem that arises from these materials is that that they are generally more expensive thus the Quantity Surveyor advises the client of a less expensive material, causing the building to lose its thermal capacity.
A solution would be to somehow demonstrate these effects of materials to a client & let them decide if the more expensive material is worth a building that keeps them cool in the summer and cosy in the winter which in turn leads to less energy consumption as well.
An application I found that demonstrates this very well is EcoDesigner (an ArchiCAD add-on), it gathers all the info it needs from your 3D model gives you a detailed energy report. EcoDesigner has a database of pre-set U-values for multiple materials, making life very easy. It is also customisable, with new legislation coming soon to in SA that all suppliers & manufacturers must supply the consumer with their project’s U-value, you can input specific values.
EVALUATION 1
To demonstrate my point I’ve constructed a simple flat roof structure inArchiCAD and
set the wall material/cut fill to “Masonry Block” & the roof slabs to “Lightweight Concrete”. When I ran a report the energy consumption added up to 301.80 kWh/m2a, which is unacceptable for any council or national regulations.
EVALUATION 2
Thus my next step is to lower the U-value of my materials. Firstly I changed my wall material to “215 block insulated, cavity, plastered”, which is a very expensive choice, however it has an excellent U-value & gives your building an awesome rating. I also changed the windows U-value from 5.5 to 1.9,
thus changing them to double glazing (EcoDesigner has all these values pre-set into a database). Now if you notice the overhangs on my building is massive thus solar radiation doesn’t influence the walls & windows too much. Thus the current evaluation will only make a slight difference.
This is another feature I like about EcoDesigner; it allows you to test your theories on the fly. Such as testing if my walls would make a difference, when I first ran the evaluation I was baffled when it didn’t make a significant difference, but now it allowed me to explore my design & made me realise what the cause was.
EVALUATION 3
Now I changed the roof slabs material to “flat roof” which includes white pebbles on the roof to reflect the solar radiation off the roof. When in EcoDesigner you can specify the exact pebble you want to use for the compositefill. Now if I run an evaluation you can see the energy consumption has dropped immensely, simply by changing building materials.
greenenergycostguru 