collapses, especially in the event of natural disasters such as earthquakes and hurricanes.

At 5:28 am on December 23rd, 2003 an earthquake hit Bam, Iran killing 15,000 people. The vast majority were killed when the buildings they were in collapsed.

Earlier that same year another earthquake claimed several hundred lives in Turkey. Similar events occur regularly but are quickly forgotten in the noise of modern news.In more industrialized nations, better economic and regulatory environments result in stronger buildings, but they are often intensely wasteful in all stages of their lifecycles. From the high embodied energy of the materials used in their construction to the inefficiency of their daily operations our modern buildings are a major cause of global climate change from carbon emissions, as well as more acute environmental problems such as pollution and resource depletion. Recent regulations and tax incentives at all levels of government are driving efforts to improve building sustainability but progress is slow and often costly.

The Root of the Problem(s)

In considering all of these problems we began by looking at the basic structure of our buildings. Consider the building of the information age as it should be; a dynamic, engineered system that anticipates change and adapts to the needs of the occupants. Instead, today’s buildings are static, inert structures of stone and glass. This shift has already occurred on the systems and environmental controls sides of the building industry, and proven quite successful. We applied the approach to structural architecture and not only developed a better way to erect our buildings, but found what we believe to be a major and often lethal flaw in the way today’s buildings are built.

While modern buildings are lighter and more dynamic than ever before, the vast majority still utilize virtually the same flooring technology that was used at the start of the great skyscraper races of the 1930’s; namely steel reinforced concrete slabs, poured in place over corrugated steel forms that are welded or bolted to lateral steel trusses. Such suspended floors are the single most common flooring choice for mid-rise and taller construction because they are cheap, simple, and very, very strong.

They are also extremely heavy and are directly responsible not only for the majority of structural collapses, but also for the majority of deaths and injuries caused by them. The majority of fatalities in earthquakes are from being crushed by concrete floors.

These same floors constitute as much as 70% of a building’s total dead weight, and perform no role in bearing vertical (tenant) loads. It’s certainly true that the floor’s role as a stabilizing membrane is critical to resisting lateral (wind) loads, but we reason that this requirement can be met by other geometric means, as described below.

In addition to their role in increasing both the frequency and lethality of structural failures, concrete slab floors are also a major part of both the monetary cost and environmental impact of a building as a result of construction. Concrete is expensive to mine, grind, bake, transport, mix, and pump, costing as much as 20% of a building’s overall price tag.

All that embodied energy also makes concrete one of the most significant carbon contributors in the world. In the last decade concrete production and use has been responsible for between 8% and 12% of all global carbon emissions.

SafetySpan - An Alternative to Concrete

Our solution is simple: replace the floors of new buildings with a stronger, lighter, safer alternative to concrete. Towards this end, we have developed the SafetySpan flooring system, a componentized structural space frame that is affixed to and suspended between the lateral beams of any building’s steel skeleton (or masonry walls) to form a rigid but dynamic structural floor cage. This cage is then protected by two layers of fire proofing panels which are further covered over by layers of flooring panels above and ceiling panels below. The system can be used to replace concrete in any tall building with little or no changes to existing construction methods or nearby members.

The structural space frame is a double-layer grid, with an octahedron-tetrahedral geometry, composed of tubular steel struts interconnected by compound hemispherical joints. The rigidity of the floor comes not from material strength, as with concrete, but from tensegrity created by the interior (compressive) chords balanced against the lateral (tension) ones. The edges of the top and bottom membranes are secured directly to the building.

This approach creates a finished floor with a greater load bearing capacity than existing concrete floors at roughly 60% the weight. This reduction in weight not only reduced the chances of collapse but minimizes the risk to occupants and emergency responders from debris and collapsing floors.

The dynamic properties of this frame also provide considerable protection against shocks and traumatic events that would weaken or shatter rigid concrete. While the cage is sufficiently rigid to provide resistance to lateral loads, our unique SafetyLock connection system is durable but flexible, making the cage behave non-linearly to shear events and sudden stresses. This allows the floor to behave more like an elastic fabric at tension than a rigid slab, allowing both P and S waves from earthquakes to pass safely through it without damage to the space frame structure.

Beyond its safety benefits, our patented threadless connection system allows reliable installation of a new SafetySpan floor, from ceiling tiles to carpet, in less than half the time of concrete and with no heavy equipment or dangerous materials. As an added bonus, this simplicity of assembly empowers small organizations and communities to erect buildings that meet their needs now and can are adaptable in the future. By lowering both the cost and the skill level needed to assemble a floor, volunteer groups can use the system to erect permanent or temporary structures that would otherwise be cost prohibitive.

Finally, the embodied energy of a SafetySpan floor is less than 1/3rd that of traditional concrete and being mostly steel, the entire system is greater than 90% recyclable. The light weight of the floor also reduces the structural requirements of the rest of the building, reducing costs and embodied energy of all other related members.

In summary, SafetySpan not only makes buildings safer by reducing the risk of collapse and virtually eliminating the potential of progressive failure, it also makes them considerably cheaper and greener to build, from construction to demolition.

Rebuilding the Building Industry

The value of the SafetySpan flooring system to today’s building industry is obvious. It directly addresses three of the most significant driving factors in the construction market: Cost, Safety, and Sustainability. It is a product that meets today’s building needs while anticipating the demands of a growing and evolving marketplace.

We intend to develop and produce the system as an extensible line of components, sold to contractors and developers through a distributed VAR network of regional resellers. Towards this end SafetySpan, Inc. is currently incorporated in the state of New Hampshire and operates an R&D lab in the town of Wilton, NH.

Initial market research has confirmed a $35B domestic market composed entirely of concrete slab flooring such as defined here, and SafetySpan meets or exceeds industry leaders in nine of the ten most important qualities as named by building professionals, namely (in order) : Low Cost, High Strength, Low Weight (= Lower Costs), Open Span Distance (again, cost of extra beams), Fire Protection Value, Catastrophic Survivability, Ease of Installation, Thermal Insulation Value, and Acoustic Insulation Value.

The product provides a number of substantial benefits to everyone in the chain of the building process. There are solid points of value to all parties, from the architects who design the buildings to the general contractors who install it, to the property manager who will maintain it for years to come. Furthermore, this is a technical industry open to change and generally welcoming new products with proven value.

Through a focused marketing campaign based on these important and demonstrable benefits, SafetySpan plans to position itself as the new standard for architectural safety and sustainability. We will leverage the truth in a value focused public relations campaign, giving public demonstrations of the strength and value of the product at appropriate venues.

SafetySpan, Inc. is currently completing prototype testing and preparing for industry certification. We are seeking funds to aid towards this goal.

SafetySpan, Inc. is operated by it three founding partners, all technology professionals who apply their unique perspectives and lessons to the SafetySpan product. They are : Douglas Leonardi, Christopher Laffey, and Todd Cioffi.