Session Chairs: Dr. Elizabeth Shotton and Marcus Donaghy
Dr Elizabeth Shotton is currently Director of Research, Innovation and Impact in the UCD School of Architecture, Planning and Environmental Policy. She teaches in construction technology and design studio, with an emphasis on sustainable building and development, at both undergraduate and graduate level. Elizabeth’s research interests are closely linked to teaching, with a focus on the sustainable use of material resources through advances in materials, construction technologies and design processes. She is currently working on an IRC funded project Minor Harbours, examining the evolution of maritime engineering in small harbours along the east coast of Ireland from the seventeenth century to the
Marcus Donaghy is currently a practicing architect in Dublin with the award winning firm of Donaghy & Dimond, and teaches design studio in the Architecture programme at University College Dublin.
Sustainable Use of Birch in the Irish Construction Industry.
Birch is a species of hardwood tree indigenous to Ireland and with a long history of practical usage here. It is a pioneer species that colonises bare ground, acting as a nursery species to enable the natural re-colonising of land, with rapid growth and a short rotation cycle (c.35-40 years). These characteristics have contributed to the species’ success in other parts of Europe, Scandinavia and North America as a biomass fuel, and as a component of wood panel products, and in the production of plywood. More recently, the advent of environmentally-conscious and cost-efﬁcient construction systems such as cross laminated timber, for example, has led to investigations into the suitability of the smaller diameter, or ‘lesser’ hardwoods for inclusion in these products. CLT panels which utilise birch, ash, poplar or black locust, for example, demonstrate increased performance in terms of compression strength, rolling shear and longevity (use-life expectancy of the panel). Inclusion of hardwood species can therefore have the effect of reducing the panel thickness required to achieve the desired performance speciﬁcations. Now, in 2016, we are witnessing CLT products coming to the market which combine softwood and hardwood species (namely; scots pine and birch). These mixed-species CLT products offer an improved-performance panel, (according to manufacturers’ advertised spec’s) as well as demonstrating a signiﬁcantly more efﬁcient use of birch timber (when compared to plywood, billets, and most engineered timber products). In Ireland, an improved population of birch is expected to be generally superior in productivity and form to previous planting stock, as indicated by the early stage growth assessments of ﬁeld trials, and it is hoped that testing of the ﬁrst commercial thinnings next year will conﬁrm the improved status of these trees. Inclusion in the grant-aid scheme for forestry planting, together with the relatively short rotation would make the species a favourable choice for forestry farmers. As the ﬁrst improved birch stands reach maturity, it would be pertinent to consider how we might optimise the construction industry’s use of this resource. This paper gives a brief synopsis of the birch improvement program to date. It considers potential sustainable uses for birch wood in construction generally, and looks more speciﬁcally at the application of birch thinnings to the manufacture of CLT products.
Coed Cymru : Exploring the architectural potential of the Welsh Forest.
value firewood at the end of their life. These trees are of inconsistent dimension and
quality, however if each tree is managed on an individual basis and processed as such,
other possibilities arise. If we can use material available locally we reduce our
dependence on unsustainable imports along with having the opportunity to retain the
inherent values of; provenance, history and non-uniform dimensions and figure.
materials in mind, could working closely with relevant stakeholders produce more
meaningful work? Irish hardwood trees planted for their environmental and recreational
benefits are of a diverse variety. The end of life use is currently being underexploited
as the wood is not appealing to mainstream markets.
city and too often they are shredded, composted or chopped for firewood. A working
document needs to be composed dealing with felled trees and currently this document does
not exist. It is the tree surgeon who controls the market. Maintenance and life cycle
care is necessary to produce higher quality timber, establishing a culture of using urban
trees will create awareness to this fact.
most urban sawlogs become the property of the tree surgeons when they win a contract.’’1
Two examples of the potential are as follows;
‘the dream is triggered by the substance’2
In this case a beech tree provides short lengths of timber (typical of non-woodland
trees) to make structures whose span and application is much greater than what is
commonly perceived. This approach is tested in the construction of a timber deck,
creating a communal gathering point in a educational setting and at a music festival.
‘It is a question’, writes Deleuze and Guattari, ‘of surrendering to the wood, and
following where it leads’3
In this case a felled tree was removed from a Dublin school, transported to a workshop,
carved into a seat and returned to the school. A video documenting the process was made
for the students. The tree had been destined for firewood.
1Dr Philip Blackstock – Independent Arboricultural Consultant, email to author 29-01-2015
2 Jo, Vandenberghe. “From the State of Grace to the State of Emergency/Borrowing from Tektonikos,” n.d.http://www.jovandenberghe.be/.
3 Tim, Ingold. “The Textility of Making.” Cambridge Journal of Economics 2010, no. 34 pg. 91–102.