Rima Sabina Aouf - Dezeen July 19
Traditional Danish seaweed thatching could be updated into a sustainable contemporary building material, according to research by Kathryn Larsen. Copenhagen School of Business and Design student Larsen became interested in the potential for seaweed architecture after studying the Viking practice of thatching roofs using eelgrass on the island of Læsø
Fireproof, Rot Resistant, Carbon Negative, Waterproof
"Eelgrass is a fantastic material that is naturally fireproof, rot resistant, carbon negative and becomes entirely waterproof after about a year," said Larsen. "It also insulates comparably with rockwool [a common type of insulation]."
"Plants grow in it, giving the effect of a green roof. It is a material that we should be considering seriously in an era of climate change."
Material Design Tested Panels
A student of the Material Design Lab at the Copenhagen School of Business and Design (KEA), Larsen went on to test what a contemporary iteration of seaweed thatching might look like. She tried different binders and grid spacing, eventually developing a set of prefabricated eelgrass-thatched panels to suit roofs or facades. Colloquially known as a seaweed but actually a type of seagrass, eelgrass is common across the UK and Scandinavia.
Potential to Farm for Industry
Larsen notes that while eelgrass levels are diminishing, there would be enough to supply a Danish construction industry, and that there are ways to farm and harvest the plant without harming the marine ecosystem. She drew on the results of a 2013 project, The Modern Seaweed House, built on Læsø by architecture studio Vandkunsten and non-profit organisation Realdania Byg.
Net Pillows for Panels
In contrast to the vernacular buildings on the island, where the seaweed is stacked into shaggy roofs about a metre thick, the Modern Seaweed House has a slimmed-down look, achieved by stuffing the eelgrass into net pillows around the facade. She also built on the work of Copenhagen architects Studio Seagrass, who have made innovative use of eelgrass in interior design and other areas.
Extensive Testing & Funds
Larsen's eelgrass panels are now eight months into a one-year testing period on the KEA roof. At this point Larsen says they are "almost entirely intact" and beginning to grow moss. The architectural technologist has secured funding to continue her research into seaweed thatching and build more prototypes in the year to come.
"I hope to test the panels u-values, to see what insulation properties they can bring to construction," said Larsen of her future plans.
Focus on Factories
Interestingly this research seems orientated toward growing raw materials for factory production of building panels. For realisation this will need small factories capable of adaptation / prototype production which is unlikely to be the case with the massive ‘little box’ production sheds currently leading the way as MMC housing producers.
DfMA to the fore!
Whatever the case, to implement this research and realise whatever benefits it offers, does need the architectural designer to understand not just the inherent qualities of the material, but how this can be componentised to work as a structure. In turn this requires an appreciation of the way they are manufactured. Transported and assembled on-site. All of this entails a shift in thinking to what is now increasingly referred to as DfMA - Design for Manufacture & Assembly. This is already available via established ‘Off-Site’ manufacturers and is quickly and easily incorporated into procedures and processes of building and development. Better still, you can make partnering arrangements with such manufacturers to gain all round benefits.
Technologically ‘SMART’ Homes
As Off-Site Construction matures into DfMA it is clearly at the forefront in turning construction workers into technical deliverer and enablers for such delivery. At the same time it is exceptionally well placed to incorporate rapidly increasing demand from buyers for their new homes to be ‘Smart’, e.g. by the incorporation of energy saving and TIoT (the internet of things) to deliver major components.
Greater Speed, Accuracy, Quality and Lower Costs via Collaborative Partnering
Greater collaborative ‘partnering’ between architects, builders and manufacturers will accomplish this The greater speed, accuracy and quality that can result from manufacturing components in a dry, controlled factory environment, together with the ability tom incorporate (yet to be invented) ‘Smart Ware’ gives home builders perhaps the only way of achieving this, together with improved on-site build quality AND controlling costs.
While resistance to the change to DfMA has been the norm, the wish of most UK Builders to deliver excellent customer service and top notch homes is now driving an increasing number to choose Off-Site for their developments. Also, as ‘OffSite Hub” note, architects and designers are moving toward DfMA, something w have been encouraging for over 20 years. The emergence of LA Developers will only speed up this process.
Easy Timber Frame
To assist them in doing so our “Easy Timber Frame “ now offers standard size modular timber frame elements for them to use as a design base, cutting down on technical design and engineering to produce win-win results.