Cork is a common interior floor finish, and has even been used as external rain-screen cladding. In 2017 Studio Bark decided to prototype a 13sqm single storey building to see whether cork could be used as the primary structure as well as the insulation layer, thus creating a ‘solid cork’ building, and eliminating the need for frames, linings, glues, tapes, breather membranes and other wet trades.
The intention was to provide a demonstration of how cork could be used in practice, and whether it could provide a viable low-cost zero-waste method of building for others to use.
The bark of the cork oak tree (Quercus suber L) grows in Mediterranean regions, most particularly, in Portugal, where there are more than 720 thousand hectares of cork forests. This bark – more commonly known as cork – has amazing qualities. It is strong, durable, provides thermal and acoustic insulation, and is resistant to fire, water and rot. The Cork Oak replaces its bark every 9 years, which means that it can be harvested without damaging the tree. The tree itself can live for up to 250 years.
Cork blocks are produced from leftover pieces of the wine cork making process. The discarded cork granules are too resinous to be used for wine corks, but are perfect for making into insulation blocks. By heating the granules they expand to fill a mould, and their natural resin is released, binding the granules into a solid block form. The largest sizes currently available are 1000 x 500 x 300, and they can be cut to size or milled.
This prototype has provided Studio Bark with a very useful insight into the possibilities of this incredibly sustainable and versatile material. The Cork Oak House will provide an opportunity develop this research further to create a unique and exceptional building.
It is worth noting that this small building has a GIA of less than 15sqm and as such need not comply with current building regulations. We are aware that a solid cork building of this nature would not comply with current building regulations due to its unproven structural capacities, uncertainty of airtightness and condensation risk. Hence why Cork Oak House provides such an important opportunity to use this ‘wonder’ material in a full regulatory context.