The New Zealand Green Building Council
Founded in June 2005, The NZGBC are the people trying to make sure buildings and homes in New Zealand are green and sustainable. They are members of the World Green Building Council and, together with Green Building Council Australia, developed and introduced the Green Star s=rating system for buildings and homes.
This rating system is what the Government announcement refers to. They are saying that all buildings covered by the requirement need to meet a minimum Green Star rating of 5, which would label the buildings as 'New Zealand Excellence' (whereas a 4 star rating would see a building classified as 'Best Practice').
The system itself is relatively straightforward. Points are scored in a number of 'Environmental Impact' categories, each of which includes benchmarks for a lower carbon, healthy project. The 9 categories are:
- Management
- Indoor environmental quality
- Energy
- Transport
- Water
- Material
- Land use and ecology
- Emissions
- Innovation
At the end of the assessment, the points are added up and a building or home is awarded it's Green Star rating:
0 - 9 points = 0 Star (assessed)
10 - 19 points = 1 Star (minimum practice)
20 - 29 points = 2 Star (average practice)
30 - 44 points = 3 Star (good practice)
45 - 59 points = 4 Star (best practice)
60 - 74 points = 5 Star (New Zealand excellence)
75+ points = 6 Star (world leadership)
Of all the Environmental Impact categories, we're most interested in 'Energy'. It's here we know our work will have an impact and can contribute towards the points total projects.
Effect of Louvre Shading Devices on Building Energy Requirements
A typical building HVAC system will account for around 40% of the total building energy consumption. That's a lot of energy being used to either heat up or cool down the building. This energy burden may be reduced through the use of sun shading, which works to keep the radiant heat from the surface of the building and reduce the amount of radiant heat entering the building.
While there is no equation which says 'add X shading to save Y energy' there are a number of studies that suggest the energy saving is substantial. A 2010 study (Palmro-Marrero et al) analysed the effects of louvre shading devices on building energy requirements in multiple cities around the world. The study showed that 50% of the total energy consumption could be saved by using louvres.
Using Shading Calculators to Maximise Energy Savings
Given the undoubted effect of sun shading on the energy burden, it stands to reason we should maximise the potential savings by designing the most optimal shading solutions. Doing so requires an analysis of the design and building geography, so we can ascertain the amount of daylight received on any given day. Knowing the results will aid the design... which will reduce the energy burden of the building... which will help the building score points towards its Green Star Rating.
All of which was a rather long winded way of saying we can help you score some points top meet that Green Star Rating requirement. And we've got a simple tool that can help too. By using the Insol Shading Calculators to do all the tricky math, you can easily ascertain the amount of shading required.
Share this tool with others and use it as many times as you like. It's completely free.
Interested in learning more about sun shading or energy conservation? Contact us here.
