GREEN BUILDING
Green Star: A construction journey to best practice
By Brett Marlin
Since our last newsletter in March,
there has been significant progress
on the Green Star rating for our new
CBD project.
Recycling
One of the things that relate to green building which is seldom
considered is recycling of waste on site during the construction process.
Most people think that if the skips are filled up, carted away and
properly disposed, this would be sufficient. But this is not so, we need
to properly recycle ALL the waste that is generated on site. We have
had to prepare and submit a waste management plan with the intention
of attempting to reduce 70% of the demolition and construction waste
from going to landfill sites by reusing and recycling the waste. We have
engaged a full time person on site who makes sure that all the recycling
is done as per the requirements.
We are separating:
• Common mixed waste
• White paper
• Plastic
• Cans
• Plastic bottles
• Glass bottles
• Wood
• Steel
• Building rubble
On a quarterly basis we are required to submit reports indicating the
waste that has been separated, details of all the loads that are carted
away, as well as details about how the waste has been used.
Initial assessment of the development
Our green consultants, Solid Green have done an initial assessment of
the development’s chances of getting a Green Star rating. We always
knew that our buildings were correctly designed and essentially were
reasonably green, but we really did not know how well we were
actually doing.
According to the GBCSA’s rating tool the minimum points
required to achieve a rating are:
4 star: 45 - 59 points
5 star: 60 - 74 points
6 star: 75 and more points
In the initial assessment without us changing our design, specification
or building practices, it was assessed that we could most likely achieve
51.2 points which is well above the 45 points required for a 4 star
building. This really made me proud as all the buildings that we have
developed in the CBD could have received a 4 star rating. It’s clear that
we are doing something right in our developments.
6
Being only nine points away from being able to get a 5 star rating
really makes one think that it is achievable, BUT, it really is not that easy
getting those extra points and there is very little point in throwing money
at it to achieve the rating. That just doesn’t make sense and goes against
our philosophy.
One of the areas where we could get additional points is by upgrading
our air-conditioning system to a slightly more efficient system, so we are
considering using a chilled water system rather than a VRV system.
VRV vs chilled water air-conditioning
A VRV or variable refrigerant volume air-conditioning system is a more
upmarket air-conditioning system than most people use in Botswana and
is certainly not only more efficient, but also more environmentally friendly
than the split air-conditioning system that is normally used in offices. We
have used this system in the Barclays Head Office in Gaborone only a
few years ago and are going to use it on this project.
When we made the decision to attempt to get a 5 star rating, Solid
Green advised that we would have to upgrade our planned air-
conditioning system to a chilled water system.
ISSUE 30 - JUNE 2017