Building on an ancient culture of reusing and recycling building components, Rotor argues that there is an urgent need to rediscover the art of destruction
Our environment is filled with built infrastructure to a point where it is sometimes hard to see how to add new function or meaning to it. Recently, some have justly called for a redefinition of architecture as a professional practice to include ‘unbuilding’ or ‘subtraction’ as a constituent part of it. The befitting metaphor, then, is that of the architect as a gardener, who, apart from knowing how to grow plants, also expertly wields the pruning shears to keep things tidy and healthy. This line of reasoning, focusing on what is left after the removal (the trimmed plant, so to say) often reveals two important points: that much building trimming happens without the need for any architect, and that usually no attention is paid to what is taken out. In the act of deciding what needs to go and what can stay, even in refined adaptive reuses, extracted materials are offcuts or weeds, sent off to garden waste recycling. (While a plant that is uprooted or cut from its stem will die off, a building component torn from a building may live several lives elsewhere.)
‘The history of architecture is full of examples of recycling and reuse. The Romans recycled their rubble in situ to make concrete’
In the coming years, the reuse of components of existing buildings will become increasingly important. The construction industry consumes raw materials in considerable quantities and produces an enormous mass of waste. Waste sorting and recycling in generic fractions (wood, aggregate, metals, glass, and so on) is not good enough. It’s an energy-munching process that – except in the case of metals – produces nothing but substandard by-products. At Rotor, we plead instead for the reinstatement of the forgotten art of slowly taking building components apart – when they need to go – in view of their subsequent reuse.
The dismantling of old buildings to the benefit of new ones is nothing new. The history of architecture is full of examples of recycling and reuse. The Romans recycled their rubble in situ to make concrete. At a time when transport took time and required a lot of energy, both human and animal, everything within reach was welcome. Abandoned buildings were used as quarries for materials intended for construction or ornamentation. Bricks were cleaned and reused as they were, timber sawn and re-dimensioned, blocks of stone chiselled to size again. Contractors conducting demolitions, up until the early 20th century, took care to break as few components as possible. Demolition sites routinely turned into yard sales, unless contractors needed the materials for their own projects.
The salvaged staircase of the Boudewijn building
Source: Courtesy of Rotor
As Jeff Byles’ Rubble: Unearthing the History of Demolition has shown, New York spearheaded the change. It started in Manhattan in the 1930s, then spread to the rest of the world: the abandonment of age-old salvage practices. Many factors contributed, apart from the fact that rubble, hauled on barges, could just be tipped into the East River: soaring wages made labour-intensive activities such as the cleaning of mortar from bricks unprofitable; soaring real-estate prices promoted short replacement cycles; steam-powered demolition machines allowed for less manpower and more speed; finally security concerns, buttressed by insurance contracts, pushed workers away from direct contact with building materials. Ever since, and until today, building demolition and waste management has become a highly mechanised industry, focused on speed and employing a handful of workers mostly operating from the safe distance of a crane or bulldozer cabin.
A series of hurdles stand in the way of large-scale acceptance of building component reuse today. Some challenges are purely logistic and relate to questions of limited supply and availability that do not emerge with new industrially produced goods. There are chances the salvaged steel beams or floorboards an architect details in their specs will no longer be available, or not in the necessary amount, when the designated contractor sets out to order them. Rotor believes the set-up of a transregional network of trusted salvage suppliers, working with digital portals providing real-time information about distributed stock availability, can already offer considerable reassurance.
‘Many materials conserve their initial performance levels, even after dismantling, transport and preparation for reuse’
New building materials come with paperwork in the form of certifications: guarantees that the product reaches certain physical performance levels, as tested in lab conditions. Given the bewildering variety found in the existing built fabric, it is unrealistic to expect every single product on the salvage market to come with similar legal guarantees. But this realisation should not disqualify the possibility of a salvage market altogether. There are workarounds. Many materials have conserved their initial performance levels, detailed in archive files, even after dismantling, transport and preparation for reuse. We also believe suppliers and designers should apply a precautionary principle: steering clear of using untested salvage materials for risk-prone applications. Salvaged marble slabs, of whatever origin, are better used as interior flooring, for instance, than as facade cladding for a high-rise.
The final hurdle is a cultural one. One of the rare terms in scholarly literature for architectural salvage is ‘spolia’ (Rotor’s online inventory Opalis is an anagram of the word). Archaeologists and architecture historians use it to refer to components that had previous lives in other structures, such as the reclaimed Roman columns of an Early-Christian church. The term is alas burdened with an explicitly negative connotation: ‘spolium’, in Latin, originally means stripped animal hide but also war booty, or anything acquired by violence. Now, an etymological enquiry shows that, in its meaning as architectural salvage, ‘spolia’ only appeared in the 16th century. It is a modern, post-factum projection (of vicious backwardness) on a widespread and honourable practice in Antiquity.
Salvaged, sorted and stored at Rotor HQ
Source: Courtesy of Rotor
Today, Belgium ranks very highly among European countries in terms of ‘reprocessing’ construction and demolition waste (avoiding landfill), with a recycling rate of 80 to 90 per cent. That advantage stems from this country’s experience in managing the rubble of the First World War, which, given the extent of the destruction, needed to happen on an industrial scale. But does it make sense to apply the same methodology to buildings that have not yet been turned into a pile of rubble? Most demolition products consist of inert materials: concrete, cast on-site and prefabricated, but also bricks, natural stones, precious marbles, rare tiles, and so on. In contemporary practice, these are all indiscriminately crushed then used as hardcore for road construction, an extreme form of down-cycling and accelerated entropy.
‘How do you select appropriate components that can be reused in a new project?’
In today’s world, the practice of reducing the materials from obsolete buildings indiscriminately to rubble (or, when talking of wood, to chipboard or fuel) has become untenable. It shows total disregard for the potential value embodied in the extracted material. Even if removing and sanding salvaged tropical woods or marbles to prepare them for reuse is labour intensive, it can be profitable if carried out properly. For authorities, there are commendable reasons to reuse: it reduces the amount of waste materials to deal with; it saves on fuel to crush building parts and on fine dust in the air; it saves carbon and increasingly precious raw materials in the production and transport of new building materials; and it creates local job opportunities. Yet to make the recirculation of building materials on a more-than-marginal scale possible again, two practices need to be urgently re-evaluated.
Modern practices of salvaging building components in Europe and North America originated in the 1970s, in a context of growing indignation caused by the loss of landmark buildings replaced by Modernist developments, especially in urban areas. What was initially a form of activism gradually turned into a profession. Today, in countries such as the US, the UK, France, Belgium, the Netherlands and Denmark, a relatively dense network of independent SMEs exists, mostly family-owned businesses, active as resellers of salvaged building components, usually collaborating with like-minded demolition contractors supplying them.
Deconstructing oak interiors of Antwerp City Hall in 2017
Source: Courtesy of Rotor
There is a gap in the market for salvaged materials from office buildings: recent urban large-scale developments. In 2016, Lionel Billiet and Maarten Gielen spearheaded the launch of a new spin-off within Rotor, Rotor DC (for Deconstruction and Consultancy), a deconstruction company geared towards such source materials. The office spaces we visit are generally fitted with glazed wall partitions, suspended ceilings, built-in lighting devices, raised floors, carpet tiles, and so on. These elements were designed according to a modular logic to satisfy the flexibility requirements of the tertiary workspaces. Yet in practice, in spite of these assets, they are almost systematically removed and destroyed each time a floor is renovated. In Brussels this happens routinely whenever there is a change of tenant; typically every 10 years but sometimes after only three. Rotor spends, therefore, a portion of time actively looking for quality buildings slated for renovation or demolition, then establishing partnerships with the owners. Rotor’s deconstruction operators typically work right before the demolition contractors start operations – they will only remove a carefully selected portion of all there is: those elements for which the prospective of resale, at a price covering all costs, are sound.
‘It is not always possible or useful to preserve everything. It is important to know where to draw the line’
How do you select appropriate components that can be reused in a new project? The cost of extraction is a decisive factor, as is the state of conservation of the part in question, its solidity, the durability of the materials that compose it, the ease with which it can be integrated into its new state, its functional and symbolic value. Our job is to take these parameters into consideration when we go through a building to decide what to preserve and what to leave in the hands of the demolishers. A poor judgement can be expensive. Our assessment of the monetary value of the components obviously depends on the market, but the latter can be influenced, stimulated. Where demand does not yet exist, it can be sparked; where supply is lacking, it can be encouraged.
The question of what can be salvaged always remains. Extracting parts of a building that needs to come down means identifying the entities that, once detached from the set, will have the best chance of individual survival, like a carefully cut twig can become a graft on a new rootstock. It is not always possible or useful to preserve everything. As with surgery, it is important to know where to draw the dotted line.
This piece is featured in the AR February 2019 issue on Failure – click here to purchase your copy today