5.1.4 Back to the Forest: Biomass Buildings are Reborn

“The forest, with its exotic forces, is “outside” the inhabited precincts of consciousness, as village, city, household or castle. But the boundaries are often depicted as tenuous; many tales begin with the protagonist living “at the edges of a forest,” just as, inevitably, the worlds of typical and archetypal impinge upon each other”. Ronnberg and Martin, 2010.

As discussed in the literature review, interest in both systems thinking and bio- inspired design of multiple genres has been steadily growing within and across the built environment sector this past several years. However, material science aside, fire is conspicuous by its absence from discussions and debates of architecture and urban design of which the creation has been attributed to ‘biological’ and/or ‘ecological’ observations. Bringing context thereto, upon typing “bio-inspired buildings” into Google the search engine generated approx. 20 pages of URLs on said subject (January, 2018). However, whereupon the word “fire” was added to the search phrase, while 6 pages of URLs were generated, biomimetic fire-resistant materials aside, none was the content as discussed fire in a ‘bio’ variant [111] built environment context. Indeed, beyond the field of fire ecology, and especially outside of the territories in which wildland fire is indigenous, awareness of the co-evolution of fire, flora, and fauna remains low, which is all the more surprising given that, as any as have a keen interest in gardening will generally be aware, wood ash is highly beneficial to the health of many common garden plants (Royal Horticultural Society, 2017), the matter thereof communicated in numerous gardening books, journals, and other media, and witnessed whereupon, as autumn arrives, gardeners build bonfires by means of both clearing dead vegetation and recycling the nutrients therefrom. Yet more surprising still is it that within the ‘bio’ creative community awareness of the symbiosis of biota and fire remains low, for one of the seminal works that discussed the potential of ‘The New Biology of Machines, Social Systems, and the Economic World’ (Kelly, 1994) briefly discussed the role of fire in making a biome variant “work” (Ibidem, pp. 57 – 62), the context being an examination of the role of complexity in the functioning of ecological systems, and the lens the career of “the godfather of ecology”, Aldo Leopold (Ibidem, p.58). Through trial and error, Leopold had rediscovered “a wary animal, once ubiquitous on the tall grass prairies, that roamed widely and interacted with every plant, insect and bird”: The animal was fire, and its role, Leopold concluded, is “vital” (Ibidem, p.59).

A yet broader sweep of said subject matter revealed misinformation being communicated in respect of the properties of biological building materials. For example, on December 18th 2017 The Building Centre published an article of which the title reads, “Sustainable, fireproof, & insulting: how seaweed is a valuable construction material” (Building Centre, 2017, online). Seaweed, it states, is “fireproof” due to its “tightly packed cellular makeup”. The article was illustrated with photographs of “The Modern Seaweed House”, which, wooden framed, and entirely clad in panels of dried seaweed piled some few inches high, resides in the midst of a conifer forest, of which specimens stand just a few feet away. While the article takes not the trouble to illuminate its readers as to the species of seaweed as was used in the prototype, the photograph suggests it to be a variant of Chlorophyta (green seaweed). Though the chemical composition of Chlorophyta varies from one species to another (Misurcova, 2011), and the genera as a whole are able to fix inorganics in marine and freshwater environments, thus their mineral content is relatively high, as photosynthesizing components of carbon metabolism at the planetary-scale, we can be assured that whatsoever the species he used in the ‘modern house’, like the oaks, elms, sweet chestnuts, and hornbeams from which Medieval London was built (University of the West of England, 2008), it is carbon-based. However, it takes not an interrogation of the molecular structure of seaweed to establish that it burns, as becomes evident whereupon one uses a variant thereof in a stir-fry. Therein, transdisciplinary methodologies seemingly absent from both the design studio in which the above referenced concept was created, and from the editorial management of the “News and Knowledge” section of the website of a leading British built environment institution, it appears that, be it at the scale of a house in a forest in some unspecified location, or that of a city, such as London, the possibility of another Thomian catastrophe of the combustible kind is requiring of urgent attention. More specifically, building materials need be understood not at the scale of a lab experiment in which a finite number of factors can be controlled, but at the scale of the environment.

Bringing the above matter into sharp relief, Sumitomo Forestry Co proposes to mark its 350th anniversary with the construction of ‘W350’: a 350m high wooden skyscraper (Hunt, 2018), the height thereof more than double that of the highest fire- fighting aerial platform currently in operation [Bronto Skylift’s model F363HLA] of which the maximum extension is 112m (Bronto Skylift, 2018). Nonetheless, not once does the press release (Sumitomo Forestry Co, 2018) as was despatched by said company by means of announcing its proposal make any reference to the risk of fire, let alone explain how firefighters would overcome the aerial platform height issue whereupon attempting to save lives in the event of a fire. But, fire’s absence from the press release is all the more surprising given that in a section titled “Cascade utilization of timber” the authors state that “Waste wood is used as fuel for biomass power generation, and the heat generated during combustion can be used to dry timber” (Ibidem, p.3). Not Schrödinger's cat, but his tower block: materials of which the owners acknowledge the combustibility in the context of a power plant, but not in the urban environment.

Reverting to the Grenfell Tower fire of June 2017, the absence of aerial platforms that could reach the highest stories hindered the London Fire Brigade in their efforts to tackle the blaze (Grant, 2017). If built, and at a cost of £4.02 billion, the 70-story W350 tower will, according to Sumitomo Forestry Co, “transform the city [Tokyo] into a forest” (Hunt, 2018, online), which is “kind to humans” (Ravenscroft, 2018). Slated for completion by 2041, 90% of its materiality is timber, including its interior structure, which spans 455,000sq/m. However, imagine not that W350 is comprised only of dead wood, for its exterior will “facilitate the spread of greenery from the ground to the top floors” (Hunt, 2018, online). Under the title “Changing towns to forests”, the press release states, “These structures are like a forest, a habitat for living things”. Though authored by a forestry company, and mentioning forests not once, not twice, but several times over, the press release of which the tone is more rhetorical than factual, speaks not to science, but to urban myth, the apparent causation the belief that a forest amounts to no more than a collection of trees, which as discussed later, is arguably a falsehood that largely serves not biodiversity, but commercial aspirations. Indeed, ecologically speaking, the W350 project suggests, loosely, there to be only one possible virtue, that being its proposed use of wood from Japanese cedar [Cryptomeria japonica] and cypress [Chamaecyparis obtusa] plantation forests, which planted in the aftermath of WWII, and covering 10.4 million ha, are monocultures that support limited biodiversity (Bird, 2017). But, sadly even in this regard, the project is lacking, for the press release states that “It is crucial to use these trees and replant them after harvesting to encourage sustainability of forests” (Sumitomo Forestry Co, 2018, p.3). Therein, the press release suggests that the forestry company seeks to perpetuate a problem rather than solve it. Furthermore, while more generally burning of biomass is “one of the worst things we can do if our goal is clean air and a liveable climate” (Stashwick, 2017), in one of the foremost seismically active nations in the world, bioenergy has been posited a safer means of energy production than nuclear (Sasaki, Toshiaki, and Putz, 2011). Therein, regardless of the level of risk to life and to property as may be inherent in the W350 proposal, it may well be that high-density urban housing of the ilk of tower blocks is not the most environmentally advantageous use of Japan’s coniferous plantation timber.

W350 is but the tip of a veritable towering inferno of possible future urban catastrophes, which, unfortunately, no matter the advent of several recent tragedies appears to be more prevalent in the minds of some movie makers than a significant contingent of the built environment press and media. For example, upon reporting that the city of Veldhoven, Netherlands plans to build the ‘Dutch Mountains’, which “once completed, will be the largest wooden building in the world” (Jewell, 2018, online), InHabitat.com’s contributor not so much as mentions the word ‘fire’, let alone interrogates the matter of how the mountainous quantity of wood will perform in the presence thereof. Likewise, when Wallpaper reported that “The future of architecture lies in engineered wood”, fire was, again, conspicuous by its absence (Dowdy, 2018).

“The Pearl is the tallest, most advanced building in the world. You’ve built a vertical city. But, you’ve brought with it every single safety and security challenge that I could think of. Not only have you brought them all indoors, but you’ve trapped them 244 floors in the air. No one really knows what things would happen if things go wrong. But, I’m just a glorified security guard, so what the hell do I know anyway”, Dwayne Johnson as the character of ‘Will Ford’, Skyscraper, Universal Pictures, 2018.

In the same month that Universal Pictures released the trailer for Skyscraper, The Economist shared a short film via its social media channels, which titled ‘Wooden skyscrapers could be the future for cities’ attempts to quantify the potential thereof. The tone is set by the opening statement, it being a regurgitation of the often cited “expectation” [on the part of a UN report of which the investigative parameters extended not to the possible impact of such scenarios as widespread anti-biotic resistance, including but not limited to extensively drug resistant strains of diseases including tuberculosis, typhoid, influenza, and Methicillin-resistant Staphylococcus aureus, otherwise known as MRSA, amongst others] that by 2050 the global population will reach nearly 10 billion (United Nations, 2015). Moving from one assumption to another, the film narrator’s states that of the sum thereof, two-thirds will live in cities, this being a speculation that though, again, commonly cited has been critiqued [112] in amongst other places an on-air discussion between LSE’s fellow of Human Geography Dr. Alice Evans, Oxfam’s public sector advisor Erinch Sahan, and myself (Urban Living is On the Rise, 2014). However, these are but drops in the stasis ocean when compared to the denial of the disorder as could unfold at the convergence of cities, climate change, and its secondary consequences.

Having acknowledged that wood acts “as kindling”, and has destroyed “large swathes of some of the world’s great cities”, thereon spoken to some of the environmental virtues of wood, the film cuts to Dr. Michael Ramage of University of Cambridge’s School of Architecture, giving a précis of the properties of Cross-laminated Timber [CLT], that being the technical term for panels comprised perpendicular layers of timber, which have been bound by glue by means of overcoming the anisotropic [113] properties of wood. Dr. Ramage then appears with a small block of CLT and a propane blowtorch, thereon applies the latter to the former, stating that “charred wood is a tree’s natural protection”, because is it “insulating”. As discussed earlier, manifold are the ways by which biota, trees included, protect themselves and/or their offspring from fire, however, biologically speaking, ‘charring’ is not one of them. Indeed, to present a block of timber that stripped of its bark and is thus reduced to that which, prior to felling, would have been a tree’s living [internal] tissues is akin to positing that a human’s internal organs constitute their ‘protection’ against environmental threats. While Dr. Ramage names not the tree species from which the CLT has been sourced, we might reasonably assume it to be a hardwood species, since its context within and of the film is that of providing structural support at the scale of a tower block. Therein, one finds the root of his phraseology. While the cellular, thereon molecular structure of the tissues of broad-leaved hardwood species varies from one to another, thus, likewise, the heat energy as might be generated from the burning thereof, all species emit sufficient quantities as to suggest that, whereupon a fire broke out in a tower made of CLT the sum would be combustible, but for one caveat: while charring has not capacity, per say, to ‘protect’ a tree, whereupon a tree’s diameter is sufficiently large the process can indeed ‘insulate’ its trunk’s interior from fire, therein retaining its structural integrity. Hence, charring has a role in fire protection at the building scale, but that role is specific. Thus, the problem with The Economist film is not so much one of science, as editing, for it fails to acknowledge, let alone interrogate the wider fire risks presented by wooden tower blocks [Fig. 53].

As witnessed by they in their millions that watched the Grenfell Tower fire unfold, fire in the urban environment is considerably less predictable than fire in a laboratory, or, as above, in a linear experiment involving one material, in this instance CLT, and one source of ignition [the blow torch]. Bringing context thereto, starting with the fuel state: a rudimentary lesson in camp-fire building is that green-wood is many times harder to ignite than dried [seasoned] wood. Hence, they building fires primarily seek dead wood for tinder and kindling. Technically, as discussed earlier, this is explained by the fact that, when the moisture of extinction exceeds a certain level, fire extent will be zero. In the instance of dead wood, the ideal fuel state for a fire is when the internal moisture levels are approx. 20% or lower (Michigan State University, 2014). While the “heat capacity of wood that contains water is greater than that of dry wood”, (Glass and Zelinka, 2010, p.4-12), hygroscopic [water absorbent], wood, whether dead or alive, “takes on moisture from the surrounding environment”, (Ibidem, p. 4-1), the amount shifting with relative humidity, air temperature, and current, this being evident whereupon one observes, for example, the state of wooden fences over time [i.e. hydroscopic processes evidenced by warping and consequent degradation of paint and other coatings]. Relating to the W350 tower, whereupon built, its fuel state, that being “seasoned”, would likewise be variable, and the predominant underlying influencers thereof beyond its creators’ control [i.e. environmental, such as weather, and human error and accident, such as water and gas leaks]. Whether built of Japanese cedar or cypress, given that both species are used for the purpose of biomass energy production we can assume that their capacity for combustion, as measured in BTU [British thermal unit] is ample to sustain a fire.

However, it takes not the perusal of a BTU chart to establish this matter, for reverting to lessons in campfire building, a Scouts’ guide states that cedar is “full of snap and crackle. It gives little flame, but much heat”, continuing in a rhyme much reminiscent of those of the 17th century (Scouts, 2017, online):

“These hardwoods burn well and slowly,

Ash, beech, hawthorn, oak, and holly.

Softwoods flare up quick and fine,

Birch, fir, hazel, larch, and pine.

Elm and willow you’ll regret,

Chestnut green and sycamore wet.”

Reverting attention from a tower block proposed for Tokyo to the neck of the territorial woods in which the Great Fire broke out, après CLT meets blow torch ‘experiment’, The Economist’s film proceeds to discuss various wooden tower blocks that are presently on the design table at London architectural practice Waugh Thistleton. By means of gaining a sense of the combustibility thereof, whereupon, as was Medieval London, these towers were built of hardwood, per 39 cubic meters, the heat equivalent would be approx. 20 million BTUs, which equates to that of “ 145 gallons of #2 fuel oil [heating fuel], or 215 gallons of liquid petroleum gas” [University of Michigan, 2014]. No scout badge in campfire building is required to recognise the scale of the risks to hand whereupon, as suggested by the architectural illustrations, the buildings, in nigh totality, are built of wood. Evidence that some laypersons can grasp such risks can be found in the comments sections below The Economist’s film, of which one response simply reads “fireproof wood” with ‘crying with laughter’ emoji.

>Continue to Chapter 5.1.5 here.

Footnotes

[111] Search phrase variants included the use of the words amongst genres of biologically and ecologically inspired and/or informed design, together with the word ‘fire’.

[112] As pointed out by Dr. Alice Evans, Erinch Sahan, and myself, the assumption that 2/3 of the global populous will live in cities fails to accommodate for the vested political and commercial interests that have propagated the belief that migration from rural to urban areas will exponentially expand in the coming century [i.e. land clearance and grabs, real estate development, access to cheap/illegal labour], and for the countertrends as are underway, including the need for more, not less agricultural development, and technologies and other inventions and innovations [i.e. mobile banking] that make services traditionally affiliated with urban living accessible in remote areas.

[113] Anisotropic refers to material strength as is differentiated by the direction of the grain of the material, in this instance, wood.

The thesis is also available in PDF format, downloadable in several parts on Academia and Researchgate.

Note that figures have been removed from the digital version hosted on this site, but are included in the PDFs available at the links above.

Citation: Sterry, M. L., (2018) Panarchistic Architecture: Building Wildland-Urban Interface Resilience to Wildfire through Design Thinking, Practice and Building Codes Modelled on Ecological Systems Theory. PhD Thesis, Advanced Virtual and Technological Architecture Research [AVATAR] group, University of Greenwich, London.