How do you design an eco-friendly building? A recent conference in Dubai aimed to give some answers.
There is much talk today about the need to design and build sustainable or so-called green buildings. But how do you actually do this? With MEP services integral to the energy efficient operation of any building, in June the Falcon Chapter of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) hosted a one-day workshop in Dubai to outline its guidance on the subject.
The event was conducted by Dr Tom Lawrence, an American-based architect specialising in green building design who is vice-chair of ASHRAE technical committee 2.8: Building environmental impact and sustainability. It largely focussed on the publication ASHRAE Green Guide: The design, construction and operation of sustainable buildings and the role of the MEP sector.
"The hvac (heating ventilation and air conditioning) system is the one that has the most influence on a building being green," stated Lawrence. "In the GCC 65% of building energy consumption is from the hvac systems."
There are several recognised benefits from designing a building and its systems to be green. Environmental benefits are gained at both the construction phase and through the long-term operation of the building; and economic and health and safety advantages should also be expected. But the success of a green building design relies heavily on the involvement of the construction team members.
"The first thing about sustainable design is that it takes into account so many disciplines," stressed Lawrence. "To integrate sustainable design practices into a project and make them work you really need to integrate from the start [of the design]. Part of green building design is not just about adding on new technologies, it's about effectively integrating them into the overall design," he added.
Lawrence explained that the recent rise in the desire to achieve USA Green Building Council's Leadership in Energy and Environmental Design (LEED) awards is helping to form a step-change in the understanding of such processes. In recognition of this, the latest addition of the Green Guide released in October 2006 includes several new features, including chapters explaining the LEED certification procedures. "One thing about LEED is it may not be a long-term solution, but the mindset introduced by LEED has changed the industry and what [firms] do when designing a building," he stated.
So what are the barriers to green buildings? Ignorance is the main problem Lawrence stressed. "Savings are being ignored," he warned. "The first issue with directors of firms is 'how much will it cost?' It is not understood that the green concept can save on capital and operating costs...80% of green building measures will give capital cost savings," he stressed.
"The barriers to efficient hvac equipment are not technical," added Lawrence. He cited the example of insulation as one factor that could directly influence the efficiency of an MEP system design. Raising the quality and amount of insulation used on a building may seem like an extra capital cost, but by doing this less cooling is required so plant capacities can be reduced, which gives a net saving. "One square metre of insulation may cost 45 Dirhams, but you will save 70 Dirhams on the air conditioning and 25 Dirhams on the electricity so will have a net saving of 95 Dirhams," explained Lawrence. "But [using traditional construction procurement] the downsizing of electrical and hvac plant is not considered when looking at raising the insulation - a truly integrated design process would ensure this could be achieved."
The use of daylight in an overall lighting design is another area that could bring large savings in energy costs, but again teamwork and the early involvement of all disciplines is required to ensure its success. "This is an area where I think interaction between architects and engineers will work. By bringing in daylight the amount of artificial light could be reduced," stated Lawrence. "An integrated design process is the only thing that can get a truly green project. In predesign you can make a building as green as you want, but as the project progresses it gets more and more difficult to make changes and [some things] may become too costly to do. The earlier the collaboration process starts, the greater the impact," he added.
Regular communications between the various team members must take place at the design stage and throughout the project life to get results Lawrence stated. By doing this, the balance of work carried out by various parties will shift and this must also be recognised in payment and contractual agreements.
The Green Guide is not intended as a rating system or replacement for LEED, but can help guide those aiming to achieve LEED certification Lawrence explained. In addition to the Green Guide, ASHRAE has proposed a standard aimed at the green building market - 189: Standard for the design of high performance green buildings, except low-rise residential buildings. Currently out for public consultation, the standard is intended to demonstrate minimum requirements for the design of sustainable buildings and provide a baseline to drive sustainability into mainstream construction.