DISCUSSION
What are you thoughts on the topics below? Let us know your points of view
1. Is it time for a Malta Green Building Standard?
There are a number of Green Building Standards that have evolved over the years. In Britain and Europe, the BREEAM (Building Research Establishment Environmental Assessment Method) Standard has become a recognised name in quality and in Green Building Standards.
The LEED Accreditation (Leader in Energy & Environmental Design) has become the default Standard in much of North America and the Middle East, whilst others include CASBEE (Japan), Green Star (Australia) and Estidama (Pearl Rating System) in Abu Dhabi, UAE.
Each country has its own context, with customised water, climate and built environmental peculiarities. Should Malta create its own Standard? And if so, should it be enforced as a national standard as the Dubai Green Building Standard (UAE) or given the speed with which the burgeoning construction industry is expanding?
Some groundwork has already been laid, with a proposal for a more holistic approach. The HEEART standard proposed by Sant and Borg is a start, but we need to go further.
“New large developments should be subject to mandatory rigorous assessment...”
—Sant & Borg, 2014
2. Low carbon alternatives to concrete?
Cement is the source of an estimated 8 percent of the world's carbon dioxide (CO2) emissions. If the cement industry were a country, it would be the third largest emitter in the world - behind China and the US. It contributes more CO2 than aviation fuel (2.5 percent) and is not far behind the global agriculture business (12 percent) [1]. The terms “cement” and “concrete” are often used interchangeably. However, concrete is actually the final product made from cement. The primary component of cement is limestone. To produce cement, limestone and other clay-like materials are heated in a kiln at 1400°C and then ground to form a lumpy, solid substance called clinker; clinker is then combined with gypsum to form cement [2].
Concrete is the most widely used man-made material in existence. It is second only to water as the most-consumed resource on the planet [2]. But, while cement - the key ingredient in concrete - has shaped much of our built environment, it also has a massive carbon footprint [5] Significant changes in how cement and concrete are produced and used are urgently needed to achieve deep cuts in emissions [1]. Alternatives need to be found, either to cement itself or to utilise more sustainable and less environmentally damaging binders [3].
Research from the Built Environment at the University of Malta, has been working to find such alternatives using cement bound materials that can lead towards more sustainable, durable buildings, with a lower carbon footprint. Quarry limestone and excavation waste have been cited as alternatives to cement and aggregate to produce strong and durable cement bound materials. In addition, construction and demolition waste, which accounts for the largest portion of waste generated in Malta, has been used to produce concrete with improved lifecycle performance, effectively resulting in reductions in raw material being extracted and in waste produced [3].
However, are we missing the obvious alternatives? Could we be utilising hemp as an alternative, or rammed earth? Or even modular buildings - the Netherlands and Scandinavian countries amongst others are leading the way, where all components of building(s) are assembled off-site and reassembled in hours or days on-site? As the crisis deepens as to the disposal of construction waste in Malta, we must look to design for disassembly or find alternative, low energy materials and construction techniques as we enter the age of the circular economy.
3. Modular building approaches - a better solution?
Currently most industrial systems are designed around a linear model, one with a definite beginning where materials are received and an end where components leave a production line. The same is true of the construction industry; raw materials are collected, processed into building materials or components which are incorporated into buildings, which inhabited, altered and at the end of their useful lives, demolished. A small percentage of building materials are re-used and recycled but globally most are discarded in landfill. Each stage in this system takes little cognisance of the previous or subsequent stages.
Natural systems on the other hand can be described as ever changing circular systems, where the waste from one process becomes food for another, such that there is no defined beginning or end. This can be described as an adaptive cycle consisting of continuous stages of (re)organisation, growth, conservation and release which relate to construction as (re)design, construction, maintenance and deconstruction (Peterson G. 2002).
Design for disassembly (DfD) is a concept that has been growing in manufacture for the last decade as a result of “extended producer responsibility”legislation and the resulting constraints on the production of waste and pollution. Within the construction industry however DfD is a new idea where it is described as the design of buildings so that their constituent parts can be easily removed for recycling or re-use in order to reduce the production of waste going to landfill and minimise the consumption of raw materials.
According to the definition Guy and Ciarimboli in their Seattle DfD guide, ‘it is the design of buildings to facilitate future change and the eventual dismantlement (in part or whole) for recovery of systems, components and materials. This design process includes developing the assemblies, components, materials, construction techniques, and information and management systems to accomplish this goal’.
The Implications of DfD for the environment include a reduction in the quantity of waste being sent to landfill, the consumption of raw materials, natural resource depletion and habitat loss. Other implications include the increased re-use of materials, which preserves the embodied energy of materials and helps reduce CO2 emissions. Also as a result of the reduced use of glues and sealants in building components, indoor air quality would be improved due to the reduced off-gassing of volatile organic compounds such as formaldehyde.
(This extract is taken from Sinead Cullen’s excellent dissertation, 2008 from CAT/UEL UK. If you would like to know more contact us here)