Updated: 6/21/03; 12:13:35 AM
    Documenting a personal quest for non-toxic housing.

The Classic Rock Realm of Ferro-Cement

The peculiar title of this article originates with the equally peculiar source of my introduction to this building technology. You see, rather than learning about this from books or by examining some building first-hand, I was first exposed to this, and the exotic styles of architecture commonly associated with it, through the album covers for classic rock bands created by the artist Roger Dean. A number of these album covers featured glimpses of very fanciful buildings designed with a sensual non-Euclidean geometry, buildings which hinted at some fantastic biorganic technology able to grow structures like plants or animals. Thinking this was just fantasy art with no basis in any real architecture, I later discovered a couple of coffee-table books on the Dean's work and was surprised to learn that the talents of Roger, and his brother Martyn, went far beyond album covers and included stage set, architecture, and industrial design concentrating on this same organic style. Even more surprising, I discovered that they had actually prototyped buildings with this unusual architecture, which they referred to as 'tectonic architecture', using simple fiberglass and planned to realize a great variety of such buildings based on the use of a form of sprayable concrete called 'shotcrete' and a system of modular inflatable forms.

Intrigued by the beauty and sophistication of this architecture, I delved deeper into its technology and history and discovered an apparently little-known world of Free-Form Organic design going all the way back to the turn of the last century and the brief but flamboyant art movement known as Art Nouveau. Starting with the work of famous artists and architects Antonio Gaudi, Hecter Guimard, and Baron Victor Horta -the three leading figures of the Art Nouveau movement- and transitioning through the expressionist designs of Hermann Finsterlin, Rudolph Steiner, and Eric Mendelson, this nature-inspired form of design later became the obsession of a small group of avant garde designers who saw in its alternately abstract and zoomorphic forms a new more sensual and naturalistic expression contrasting against the rectilinear geometry dominating conventional architecture. Though never widely appreciated, this Free-Form Organic design movement has oscillated constantly between popularity and obscurity depending on the ability of individual personalities to attract and hold media attention. However, the orthodox architectural establishment has generally ignored this movement, in part because the technology involved has readily lent itself to outsiders with a great deal of work produced not by professional academically trained architects but rather by self-educated artists. Non-Euclidean geometry also presents complex engineering issues that compel designers to rely more on intuition than hard scientific structural analysis and that defies the convention of professional design. To date this movement has produced some of the most beautiful architecture in the world, and yet much of it remains unknown to the general public.

At present the most well known designers exploring this type of design are the brothers Roger and Martyn Dean, Eugene Tsui, Kendrick Kellog, Antti Lovag, Luigi Colani, and Peter Vetsch.

Tectonic architecture - Roger and Martyn Dean

Roger and Martyn Dean is probably the most famous of all organic designers since Gaudi, chiefly by virtue of their fame derived from a rock music cultural presence. But they have virtually no body of built architectural work, their only piece being a demonstration vacation cottage developed for a defunct theme park project.

Eugene Tsui

Eugene Tsui stands out as the leading designer in the zoomorphic discipline, his work rooted in animalistic forms and decorations to the point of being quite baroque in appearance. He is also notable as being the only designer in this movement to have proposed very large structures -even Arcology scale structures such as his mobile island community Nexus and his two mile tall Sky City. Tsui also employs a unique hybrid structural approach, often combining structural systems like geodesic domes with the more free-form ferro-cement.

High Desert House - K. Kellog

K.Kellog is perhaps the most sophisticated of all current Organic designers and the most respected among the architectural mainstream, perhaps because his work spans the broader spectrum of Post-Modernist Eclectic design. Like Tsui, Kellog employs a lot of hybridization of composition, which is common to the Post-Modern Eclectic aesthetic, and makes just as much use of wood, natural stone, and other materials as ferro-cement. A synthesis of 'organic' design in the Wrightsian sense with the free-form aesthetic. His structures actually tend to derive from Modernist pavilion structures, his organic forms tending toward macro-structural elements which enclose large clear-span spaces rather than building up from cellular room elements. Still, he makes extensive use of integrated furnishings despite an open-plan layout approach, sculpting elaborate interior landscapes within these larger clear-span spaces. His hybrid composition makes his work extremely complicated and expensive to build and limits its use to the wealthiest of clients. This has tended to limit his body of work, since clients who can both afford and aesthetically appreciate such costly and sophisticated architecture are extremely rare.

Le Palais Bulles - Antti Lovag

Antti Lovag is a pioneer in ferro-cement design but a figure I have not been able to find out much information on even though he has apparently influenced many European designers. He has one very famous work called Le Palais Bulles (The Palace of Bubbles) in the French Rivierra which he designed in conjunction with Pierre Cardin but all information on it seems limited to foreign language texts.

Luigi Colani

Luigi Colani has a career similar to the Deans in that his fame comes not from his work in architecture but rather from his work as an industrial designer. His biorganic vehicle designs are his trademark, and precious few of those have been developed beyond models despite his great fame. However, his interior and architectural design work demonstrates an extremely high degree of ergonomic refinement, as if they were designed with the same ergonomic engineering applied to the cockpits of spacecraft and sports cars.

Peter Vetsch

The current designer with perhaps the largest number of built structures may be Swiss designer Peter Vetsch, who has developed a whole community in a town called Dietikon using this style of architecture. Seemingly inspired by the work of Antti Lovag, Vetsch could be said to be the most conservative of Organic designers in that he makes very limited use of integrated fixtures and furnishings in his design and relies on more abstract shell forms of less complex detail, allowing residents more freedom in interior design using their own choice of conventional furnishings. This makes his work, perhaps, the most publicly accessible of all current Free-Form Organic designers.

From a design methodology standpoint Free-Form Organic architecture is unique in that buildings are often designed with an interior precedence starting with room 'cells' as the primary design element. Rooms are regarded as a logical sphere which is deformed into a function-specific organic shape integrating many, if not all, of its functional fixtures. The collection of cells are then integrated into a seamless organic whole according to the desired flow of movement through the structure and the specific characteristics of the site it is situated in. Not strictly functionalist in approach, various abstract or zoomorphic forms may feature in the overall design -further modifying the structure of cells- and in the small scale detailing. Because of this inside-out approach to design there is often an aesthetic and functional dichotomy between interior and exterior topologies. Or to put it another way, often non-Euclidean shell structures that are very beautiful and practical on the inside result in exteriors that are simply bizarre and problematic. This has often been moderated by the use of earth berming that essentially hides the exterior from view under a less convoluted landscape form. Another approach is to cultivate the growth of plants over the exterior shell surface to likewise disguise the convoluted forms as some kind of massive plant. Both these approaches offer additional benefits in thermal performance for the structures. Another approach is to simply 'average out' exterior convolutions with a secondary exterior shell structure of a simpler smoother macroform, much as would be created by earth berming. This is particularly effective when employing a double-skin structure where hollows are filled with foam insulation and can serve to protect and conceal infrastructure systems that are commonly arrayed along the shell exteriors. The Dean brothers have been particularly adept at resolving this conflict through the use of zoomorphic macrostructures and Art Nouveau inspired external roof and siding treatments.

ferro-cement construction

Key to this Free-Form Organic design movement is a remarkably simple but powerful technology known as ferro-cement which appeared around the turn of the last century and which, despite this age, remains the single most versatile building technology human civilization has so far devised. One of its original applications wasn't buildings at all but rather cement hulled yachts, an application for which it is still used to this day. The ferro-cement technique is a simple one. One simply constructs a wire mesh and rebar structure to which is applied a fine aggregate cement mix by hand, trowel, using an hand operated sprayer called a tirolessa, or a high volume cement sprayer driven by a peristaltic pump. The cement layer used is quite thin compared to slip-formed concrete construction and a high strength-to-weight ratio is common to ferro-cement, hence its marine applications. Little finishing is required for ferro-cement structures beyond what is desired for cosmetic effect or needed for critical waterproofing. A plaster finish inside and out is common. No high degree of skill is necessary for this construction technique but it is inherently labor intensive, the crafting of the mesh frames and sculpting of small scale details comprising the most labor intesive work. Construction cost is extremely low -some have estimated it at less than $2 per square foot sans labor. But accurate cost estimation is difficult since there is commonly a great sculptural quality to the architecture and hence an extremely variable labor overhead. Many ideas have been explored to reduce the labor with this technology, the most successful being the use of mechanical sprayers, inflatable forms, and pre-fabricated foam core rebar panels sold under a variety of names.

The great virtue of this simple construction technology, and the reason for its use in Free-Form Organic design, is its ability to assume any form imaginable. But this sword cuts both ways. It allows impractical and unsafe forms just as readily as it supports strong and safe ones, which has at times led to dramatic failures for amateur builders. Likewise, while some of the most beautiful structures in the world have been produced with this, so too have some of the most hideous! And even when the results are good, the non-Euclidean forms of Organic architecture tend to produce a highly polarized response from people. They either immediately love it or hate it and often even when they love it they can't visualize it as practical or comfortable for their own home because it comes to them with no cultural frame of reference. It is like architecture from another world.

This is clearly a technology where the hardware is far ahead of the curve for its software. Indeed, even in a literal sense. There is currently no architectural CAD software capable of performing both design and structural analysis work on complex non-Euclidean structures and when Organic designers use computers at all -which is rare since they often prefer a hands-on sculptural approach and initiate designs using simple modeling clay- they are forced to use a patchwork combination of modeling and analysis systems. This has tended to limit the scale of Free-Form Organic architecture developed since the lack of any formalized method of structural analysis makes very large structures difficult to engineer. But this has presented no severe limitation for structures on the scale of individual homes, the inherent high performance of ferro-cement making it fairly forgiving. The chief challenge for home scale structures has been ventilation, due to the impermeability of the material and the very complex air flow paths produced from these complex forms.

Outside of the Organic design discipline, ferro-cement has been frequently used for structures as vast as large aircraft hangars and stadium domes using simpler monolithic shell forms. The less complex shapes of these large structures, even when using curves, are no particular problem to analyze since they are generally symmetric and planar, rather than be complex conglomerations of spheroids. In addition it has been used for constructing hulls for ships since its introduction and is commonly used for water tanks and silos, swimming pools, culverts, viaducts, pipes and tunnels, agricultural and industrial shelters, kitchen and bathroom counters, baths and shower enclosures, outdoor sculpture, landscape ornamentation, stage sets, theme park decor, and simulated rock and coral features in gardens, zoos, and aquariums -that last application being especially important in an environmental sense as we will discuss a bit later. So ubiquitous is this technology that its relatively rare use in architecture is itself an oddity.

As a building material ferro-cement offers high performance and superior durability at low cost and is inherently non-toxic. It's very well suited to the needs of non-toxic housing both because it is based on non-toxic materials and because its construction is monolithic and hence greatly reduces the variety of materials the finished home requires. But it is not a breathable material, has poor insulation value, and there is no practical alternative to the use of wire mesh substructure for those individuals who have a need for eliminating metals due to EMF sensitivities. Insulating these structures can be a tricky process -especially when using an Organic design- and usually involves either the application of foam insulation on the inside or outside surface and plastering over it or, more effectively, creating a double-shell structure using pre-made foam panels attached to the subframe, sprayed foam on an inner core mesh, or some hollow core system which can have foam injected. This double-layer approach is preferable because it allows for durable small scale features on both interior and exterior. It also allows for the creation of sheltered ducting for plumbing and wiring. The ability to integrate a lot of furniture features directly into the structure of the home is of particular benefit to the EI resident because it reduces the cost of home furnishing and insures furnishings are non-toxic. But this comes with a compromise. It is impossible to change a ferro-cement structure once built without performing surgical demolition and the structure can only tolerate a limited amount of such modification before completely losing its structural integrity. This is particularly critical with Free-Form Organic design and designers have varied in the degree of integration of furnishings they employed according to their sense of confidence in the long term functionality of their designs. This is in increasing concern today, where the average home is rearranged so much over its lifetime that it has become rather idiotic for them to be based on anything but clear-span structures devoid of any internal load-bearing walls. Clearly, a high degree of design skill is critical in making extensive furniture integration practical.

Another virtue of ferro-cement is its ready suitability for earth sheltered structures which goes far in ameliorating its limitations in thermal performance. A great many Free-Form Organic homes have featured partial or complete earth covering, combining the practical benefits of low energy and maintenance overhead with an aesthetic aspect of integration into the natural landscape, reflecting a harmony with nature. Ironically, this form of architecture is not generally accepted as a 'sustainable' architecture by 'Green' advocates because of the belief that the use of industrial materials -cement and steel mesh- is environmentally inappropriate. I believe this to be very shortsighted. Sustainable architecture advocates are generally rather obsessed with the composition of homes over their immediate impact on the environment. In other words, the environmental impact of what a home is made out of is more important to them than the physical impact of the home itself on the environment, and this may have more to do with an anti-industrial/anti-corporate sentiment than a rational evaluation of net environmental impact. After all, land is the single most critical natural resource and if that isn't being used efficiently, what does structural composition matter? Levittown would still be Levittown even if all the buildings there were made out of straw bales.

The dirty secret of sustainable architecture is that 'soft' technology is a double-edged sword. What does this mean? Soft technologies are technologies of urban/industrial decentralization. While they reduce environmental impact they simultaneously reduce, at decreasing cost in quality of life, their user's dependence on the urban/suburban utilities and industrial infrastructures which have long limited the pace of community expansion. If your house is grid-free, sewer-free, water mains-free, wired network-free, and -thanks to the ubiquitous SUV- road free and you have the option to work from home via telecommuting, what then is there to stop you from building a home ANYWHERE? The better soft technologies become the greater the independence they afford and, while this may be very good on a personal level and go far to reduce environmental impact for doemestic energy use, at the current rate of evolution there will, within about 20 years, be nothing to stop people from building homes and living perfectly comfortably anywhere on the planet, in any habitat no matter how remote or severe. Even the middle of the ocean will soon be potential housing real estate. (don't believe it? Just ask Bob Ballard. He's now developing the technology for that!) 20 years ago most new suburban development in the US bordered farmland. Today most new suburban development borders previously unspoiled wilderness. 40 years ago cities were the most popular place for the wealthy to live. Today it's the wilderness. We are in the midst of what I've come to call a 'rural sprawl' and the Green movement is partly responsible for this. They have done very well at making the public appreciate the environment to the point where access to it has become a key measure of personal quality of life. And -for better AND worse- they continue to advocate the technologies that make access to the wilderness easier by the day. We've turned the wilderness into a domestic commodity and now everybody wants a piece of it.

This situation has compelled me to regard the current precepts of sustainable architecture as largely inadequate. It's no longer enough for a home to be, in just composition and energy use, low impact. It must physically impact its immediate environment as little as possible to the point where it gets completely out of the natural habitat's way. This is probably of greater priority than its composition. We can enjoy the luxury of immersion into wilderness but only if we have the will-power to define a strict demarcation between us and nature and learn to leave what's beyond the border of our walls alone.

The genie is out of the bottle as far as industrial decentralization is concerned. If current trends in technology hold, this century will see the complete obsolescence of community utilities infrastructures and centralized manufacturing. By the turn of the next century most people will make -on demand- most everything they need in their own self-powered homes and discard it for immediate recycling as soon as they are done with it. 'Products' will be reduced to the software that makes them and most industrial corporations will be history. It will be a complete throw-away culture matched to the capability of total recycling and renewable energy independence. Sounds great, but how will we prevent this civilization from suburbanizing the whole planet? We probably can't -not unless environmentalists stop demonizing cities and architects and urban planners put serious work into the task of making cities so high in quality of life that everything else seems squalid in compsrison. That may not be possible in cultures that equate physical space with quality of life and when racing against shrinking technologies of independence which have a long head-start. The best we may be able to do is make the fabric of that unavoidable mega-suburbia as low in impact on natural habitats as possible.

And that's where ferro-cement and Organic architecture, with its ability to merge with pre-existing landscapes and mimic natural geology, comes in. This is a technology that affords architecture the ability to disappear into the landscape so completely that the processes of nature can carry on more-or-less unimpeded above and around it. This technology allows us to design a new class of sustainable architecture that seeks to be invisible in the natural habitat and which internalizes most human activity so as to isolate that it from the activities of nature it might otherwise disrupt. But, unfortunately, transportation technology lags far behind and threatens to eliminate any environmental benefit this more conservative sustainable design strategy might afford. The automobile curses us with its dual characteristic of being dangerously primitive but creating the illusion of sophistication and convenience. We need a transportation technology as non-impactive as this 'invisible' architecture and, similarly, it may have to go underground. The technology for that remains in infancy due to disinterest and so it remains unclear if it could be implemented in time to help save the environment from literally being loved to death.

A Random House - Malcolm Wells - a suggestive approach to merging housing discretely with existing landscapes

example of geo-mimicry using ferro-cement, Las Piedras Tecate, Mexico, by architect Jim Hubbell

Long being a fan of Free-Form Organic design, I have long been interested in using this style of architecture for a home of my own. And being one of the few people who actually have a practical reason for living on the edge of wilderness, I am concerned about preserving the clean natural environment I am so desperately in need of. But the high labor and talent overhead of ferro-cement construction remains a critical obstacle. While there are a handful Organic (from the Green and Wrightsian disciplines) designers who specialize in non-toxic housing, there are no designers in the Free-Form Organic design movement with any interest in this area. Being more artists than architects -even for the community of avant garde architects- the issues of baubiologie do not seem to have come within the field of their radar and so non-toxic design is as new to them as it is to most architects. Are there ways to employ this non-toxic technology without the benefit of talented designers and with much reduced labor? A few things offer some possibilities.

Many people have recommended the Monolithic Dome system to me. This is a widely used system which many people have used to create dome homes of their own. It is based on the use of a pneumatic dome form attached to a pre-made concrete slab floor inside which is erected a rebar mesh and to which is applied sprayed insulation foam and finally a layer of shotcrete. The pneumatic form is not reusable in the version of this system the Monolithic company regards as 'habitable'. It is kept as a permanent protective skin which, due to its plastic composition, tends to deteriorate within a decade and needs additional applied coatings. This can be removed and a second shotcrete skin applied to the shell from the outside but this doesn't double the cost. The Monolithic system greatly reduces labor overhead compared to typical hand-crafted ferro-cement construction because the shape is simple and the kit of components is pre-fabricated. But in practice Monolithic Domes offer no particular savings in cost compared to conventional construction and the plastic pneumatic form and use of sprayed polyurethane foam make it impossible for me to build with myself. Domes are also not as efficient in practice as in theory and the simple large dome form lacks the functional benefits offered by the sophisticated cellular interiors of Free-Form Organic design.

A potentially superior technology to the monolithic dome process is the Mini-Shell system developed by Dante Bini. A small scale variation of his Bini-Shell system for very large scale pneumatically lifted concrete domes, the Mini-Shell system uses a fully reusable form to create square and octagonal based domes with two or four arched openings. It has been used to make thousands of buildings, mostly in Australia. The Mini-Shell system works by placing an uninflated pneumatic form on a pre-made foundation slab and then constructing a flat but flexible rebar frame on top of the form. Conventional concrete is then poured onto this flat structure and once it begins to set the pneumatic form is inflated under the wet and plastic concrete, lifting it into its final shape. Once fully set, the form is removed for reuse and the rigid shell is finished by spraying foam insulation on the inside -which is finished with paint or plaster- and then installing simple rectilinear windows in the arched openings. This system has many advantages over the Monolithic dome. The use of poured concrete eliminates the need for special concrete pumps and special shotcrete application skill. The flat based shell units accomodate conventional furniture more easily and can be joined together to extend structures in any direction, the form reused for each added shell module. The simple arched openings make window and door installation easier and offer large attractive views. There is also a possibility that the Mini-Shell system will work with pumice-crete instead of conventional concrete and as a result allow shells to be self-insulating, eliminating the need to spray insulation foam on the interior. But the Mini-Shell system remains completely unavailable in the US and, again, would still require the help of a team of volunteer workers.

Perhaps the most likely alternative to hand-crafted ferro-cement is the use of pre-made foam-core rebar panel such as the ICS 3D-Panel system , Monolithic Panel system, and the Tridi-Panel system. These products are basically pre-made mesh frame structures for traditional ferro-cement technique with the bonus of built-in insulation. They greatly reduce the labor overhead in ferro-cement construction and can be used in the construction of radiant heating equipped floor slabs. One simply cuts them to the desired shape, wires them together, cuts wholes in the insulation foam to place utilities conduits, and then applied concrete as normally with hand-crafted ferro-cement. They can be cut to most any shape and bent to form large curves, barrel vaults, and cut into pie segments or geodesic panels to form domes. I have already proposed the use of these products for my Simplicity Concrete pavilion home design, as described in the earlier Simplicity and Pavilion Architecture article. This is probably the simplest of all possible ways to use this technology for home construction.

These pre-made foam panels do lend themselves to use for Free-Form Organic design when used in conjunction with traditional ferro-cement methods, the pre-made panels functioning for large scale features and the traditional mesh serving for small scale ones. But they are easiest to use in simple rectilinear forms and have commonly been employed in low-income housing using that -typically south of the border. This should be adequate for non-toxic housing but still remains beyond what I could use by myself. It's still something that needs a team of volunteers, even if it may be easier than any other ferro-cement approach. Despite this limitation, this does look like a very strong contender.

One of the most interesting approaches to the use of this material -and one which comes back to my premise that sustainable architecture needs to merge better with the natural landscape- occured to me recently while thinking about possible ways to make the Simplicity Concrete pavilion home concept even simpler. It occurred to me that natural boulders could readily serve as alternatives to man-made structural columns if simply distributed in a loose array. Thus a pavilion home structure could be built simple by arranging some natural boulders in an attractive cluster, tracing a flowing organic roof and floor line around them, pouring a floor slab with radiant heat and utilities conduits around the boulders' bases, then assembling a single large panel of foam-core rebar panel, cutting holes through it for some of the boulders to penetrate, cutting a flowing organic edge perimeter line, installing from fiber-optic lighting, and then spraying it with colored concrete to compliment the color of the natural stone. A perimeter window-wall of planar glass panels would provide enclosure and wood frame portals would penetrate the glass at strategic points to provide doorways. With that the home would be largely complete. Though not as 'invisible' as Free-Form Organic design would be, this would at least well compliment the landscape, especially in a desert environment and with the addition of roof-top rock and cactus garden. However, the cost of transporting large boulders any great distance would be prohibitive so for this concept to work the site itself would need to provide the necessary boulders, either in an already suitable natural cluster or within close enough distance that it would be practical and cost-effective to drag them into place by bulldozer.

Alas, as much potential as this technology offers for non-toxic housing, and as much as I would personal enjoy a Free-Form Organic home merging seamlessly into the landscape, it remains inaccessible to me without the help of others. I see no solution to this fundamental obstacle.

Copyright 2003 © Eric Hunting.