The rigid-frame method has contributed to excellent advancements in application of photovoltaic (PV) panels to roof systems. At a minimum, building operators can use this method to reduce their dependence on outside power, and it is even possible for them to become completely self-sufficient by supplying their own energy. Common solar options include traditional crystalline or silicon panels, although some industry manufacturers have also worked with a thin-filmed PV that adheres directly to the building’s fabric panels. Another, less-sophisticated system for solar heating during winter months utilizes perforated metal to capture hot air in a cavity and bring it into a structure.
Although current truss-style fabric structures are lightweight and less expensive to produce than a rigid-frame building, they do not adapt to additions to the roof, such as solar panels, or to any operational devices required in a building, such as conveyors or cranes. This means the life cycle cost of rigid-frame buildings will be considerably less than a standard truss and hoop system.
The design of a rigid-frame fabric building makes it relatively simple to add items such as interior fabric liners and insulation to the roof and sidewalls—a method allowing installers to achieve a certain level of temperature control. This combination of liners and insulation material can achieve insulation values of up to R-40, which is a rating that meets almost all applicable energy codes.
Rigid-framed fabric structures allow for the type of continuous liner that truss systems cannot accommodate. This means no matter what level of insulation is installed, this roofing style can provide a near-airtight building envelope, helping users save significantly on heating and cooling costs.
Certain insulation packages may require some of the building’s translucent fabric to be covered, but even structures demanding insulation and natural light can reap both benefits when a fabric skylight is included in the building design. For this to work, it is critical to reserve a large section of uninsulated fabric while still applying enough insulation to meet energy codes.
Another factor impacting a fabric building’s interior environment is ventilation. This can be addressed through passive or mechanical means. A rigid-frame structure can support mounted loads such as fans or heavy-duty ventilators if necessary, or a natural gravity ventilation system can be implemented.
This latter system relies on the simple movement of hot air. As warm air rises, it interacts with pressure intakes at the base of the building’s perimeter and with a gravity ventilator at the ridge, effectively creating circulation throughout the inside of the structure. By providing a natural intake for fresh air and an evacuation point for fumes without the need for powered equipment, users can further cut down energy consumption and operating costs.
Resources and results
On top of being naturally energy-efficient, tension-fabric buildings typically make responsible use of existing resources. For example, the structural steel I-beams in a rigid-frame fabric structure contain about 90 per cent recycled steel. Basic accessories such as gutters and downspouts to collect rain runoff into cisterns can also be applied to the building, allowing for onsite water management.
The number of building users who recognize the importance of energy and resource management is continuing to grow. Thus far, energy efficiency has mainly been a function of economics—applying logical green building principles reduces energy consumption and utility expenses. However, the environmental aspect of the equation matters, too (though building operators who need to be wary of the bottom line are understandably slower to adopt new technology for environmental benefits alone).
Whatever the motivation may be, committing to sustainability makes sense. The grass may not always be greener on the other side, but with the right approach, a building easily can be.