Going for gold
Experts explain what makes Mirdif City Centre a sustainable place
Mirdif City Centre may have opened last month, but the pressure is still on for Majid Al Futtaim Properties and its team of contractors, as they wait to hear if their flagship retail development will become the first mall in the MENA region to achieve a LEED Gold rating.
After submitting the required documentation, the developer is quite sure that it will reach its goal, but it will be a couple of months before the news – good or bad – is announced.
“We have done a lot of pre-calculations and we are fairly confident that we will get the certificate,” says Majid Al Futtaim senior vice president for project management Jonathan Emery.
Under LEED v3, launched in April last year, between 60 and 79 points need to be achieved for a new construction project to be rated as LEED Gold, while the ultimate Platinum rating requires 80 points or above.
So why didn’t the client aim for the highest green accreditation?
“We set ourselves the target of LEED Gold, which was the highest standard we felt, was in our push,” Emery explains. Adopting the green system, however, created a lot of challenges for both the client and the contractors during the construction of the mall, says Peter Cummings technical director for WSP, the MEP consultant on the project.
“At the time of inception of the project, the LEED rating system was very new to the region and was also new for the majority of the team.”
To help overcome this challenge an education programme was run, introducing all team members to LEED. And, as time went on, a number of employees became LEED certified professionals.
“Frequent workshops were held throughout the project design and execution phases. These workshops comprised representatives from every discipline to help drive LEED credits through,” Cummings adds.
During the construction of the project, 20% of energy consumption was saved through various initiatives, such as the selection of sustainable building materials and the reduction of construction waste.
The client looked at reducing the amount of waste physically generated by construction and therefore invested in tools that could be used time and time again, such as shuttering – a type of formwork equipment.
As a result of such schemes, 50% of construction waste was diverted from landfill sites during the 31 months of development.
It is also important to all those involved in the project, that the mall has a sustainable future, and to ensure this would happen, energy needs to be saved during the building’s life time and not just during the construction of the development.
Luckily, consultants were onsite to meet these requirements. Architect RTKL was charged with designing the mall, as well as delivering a scheme that was environmentally responsible.
The company’s director Ken Christian says that the entire project team was keen to follow the LEED protocols.
“A lot of a LEED Gold rating has to do with the team’s level of commitment from design to construction to operations. The other has to do with getting the planning done correctly and understanding the relationship between building configuration and energy modeling.”
Indeed, planning is important. Sustainable building can be complicated and it is made doubly difficult when it comes to malls, due to the knocks and bangs it receives from thousands of people walking through it each day.
In addition, retail architecture goes out of date because it is centralised around fashion, but it also needs maintaining more regularly than say, an office building because of the need to dazzle and attract a wide customer base.
Holford Associates, which has now been acquired by Hyder Consulting, acted as the lead consultant on the Mirdif City Centre project and advised which robust solutions should be implemented in order to prolong the building’s life.
“We chose marble for the floors, which spreads across 42,000m2 of the mall. It is an extremely durable type of marble, which will last a long time,” says Holford Associates project director Ian Baker.
The company’s contribution to creating an eco-friendly development also included the selection of natural lighting and energy-saving systems, such as waterless urinals.
“We have worked with MAF on several occasions and Mirdif City Centre is actually a product of lessons learned on previous projects,” adds Baker.
WSP also designed systems for the project, which aim to minimise energy consumption.
“Sustainability was always on the agenda and pursuing LEED meant efficient HVAC systems were a must. Essentially the brief required the designer to provide a central cooling plant with a high degree of efficiency and flexibility,” says Cummings.
“The total cooling capacity at the moment is 53.4MW. The safe refrigerant that has no ozone-depletion potential
and no phase-out schedule and the chillers have very high efficiencies.”
Variable volume supply air handling units are being used to cool the main areas of the mall and the building utilises low flow fixtures to minimise the consumption of water.
The project also has a metering strategy with remotely monitored energy and electrical meters integrated with a building management system (BMS) to ensure the LEED measurement and verification credit is attained.
“The chilled water systems are also extensively metered to enable the operator to determine when and where energy is being consumed,” adds Cummings.
So, the systems are in place and the client’s main goal is clear. What’s important is the company doesn’t lose sight of how the mall can continue to save energy for years to come.
For now, experts believe that Mirdif City Centre will set standards for future development. “The commitment the team had to the LEED certification will set Mirdif City Centre apart and likely build momentum for others to follow suit,” says Christian.
Mirdif City Safety
Combisafe Gulf director of operations Bruce Shahabi explains what safety systems were implemented during the construction of Mirdif City Centre
Which specific products and solutions did you supply to the project?
Combisafe supplied a steel mesh barrier to perimeter edge of the cast slab floors and some formwork systems. We also supplied a safety net fan system (fall protection system) to the perimeter edge of cast slabs with special focus of access ways and large floor openings.
How does the development differ to other projects you have been involved in?
The shear size and footprint of the site made supervision a challenge. The tight project duration put a lot of strain on the field service and the material supply side. However, the contractor, Alec, was quick to recognise the problems and risks to falls early and plan well ahead to design out the risks.
What type of safety measures have to be considered on this type of project?
Recognising the risks during planning stage and sourcing the right equipment for fall prevention and protection systems before facing the problem on site are key factors on such projects.
Consideration must be given when selecting a fall safety system for the level of supervision, maintenance and ease of use on large scale projects as such. Alec also employed a rapid reaction unit within their safety team on their projects, which enabled them to react in a systemised and organised manner should something had gone wrong.
WSP lists some of the green strategies and engineering technologies adopted by Mirdif City Centre
- Adopting erosion and sediment control measures to protect environment.
- Ease of access to public transit systems.
- Use of non-potable water for irrigation.
- Use of water efficient flush and flow fixtures.
- Compliance with ASHRAE 90.1 Appendix G – Ashrae’s building energy standard.
- Development on an urban site thereby minimising environmental impact due to land development and leverage existing urban infrastructure.
- Elimination of chlorofluorocarbon(s) for the project refrigerant plant.
- Use of energy efficient and eco-friendly equipment.
- Improved façade design.
- Using energy efficient light.
- Using daylight control and occupancy sensors.
- Use of chilled water using compliant refrigerant.
- Measurement and verification – installation of BMS and having plan for the base building and sub-metering for energy conservation.
- Storage and collection of recyclables for the project.
- Diverting 50% construction waste from landfill.
- Use of non-toxic eco-friendly materials.
- Use of materials with high recycled content.
- Use of materials with high regional material content.
- Quality indoor air for human safety and comfort.
- Declaring buildings as ‘non-smoking building’.
- Green education policy.
- Design exceeding fresh air requirement of ASHRAE 62.1-2004 by over 30%.
- Use of environment friendly low emitting material for maintaining proper indoor air quality.
- Thermal comfort design complying with ASHRAE 55-2004, section 6.1.1.
- Use of eco-friendly housekeeping chemicals.