Will the cities of the future be built of wood?

Contemporary worldwide trends suggest a growing interest in the potential of wood for the future of construction and the ecology of urbanization.

Wood in construction have been used by societies around the world for thousands of years, although in the modern era, interest has shifted towards materials such as steel and concrete. But today its use is reviving because of its unique qualities, but its use remains largely unknown.

Relevance of timber construction.

Wood is the focus of debates about sustainable development, construction and material use. Its use is reviving because of its inherent properties: carbon storage, rapid cycle of regrowth, light weight and easy workability, lower processing requirements and potential renewability.

Construction-grade timber and engineered forest products are some of the highest value products from trees. Furthermore, following primary use as structure, there are many secondary or tertiary uses for timber construction waste that retain its value.

Techniques of timber construction.

There are limitless possible designs, and construction is based in both engineering and cultural practice. Although a number of global architects have begun designing and constructing modern buildings using timber as structural material, the designs developed so far often propose the use of timber in construction as a simplistic substitution of the most common materials that currently compose our cityscape, such as concrete and steel. This vision tends to forget the full potential of timber, inherent in its intrinsic properties. For example, wood has a singular combination of thermal, hygroscopic, mechanical and ecological properties.

It is true that regular timber isn’t moldable like steel or concrete, and it isn’t strong enough. But new engineering solutions have developed new timber construction material, such as Cross Laminated Timber, comparable in strength to concrete and steel.

Its low thermal conductivity of could be useful for reducing the risk of thermal bridges, and also, it naturally regulates heat and moisture. Furthermore, although the thermal mass of timber materials is not comparable to concrete or masonry, wood naturally changes its internal temperature behind changes in the external temperature. This could be efficiently used to reduce summertime overheating from high external temperatures and can also aid in levelling out daytime and nighttime temperatures by transmitting heat from the middle of the day through the night.

Wood presents unique opportunities for architecture today. Rather than the simple substitution of timber for steel and concrete, it should be seen in relation to its properties and implications from a trans-scalar approach, thus as generative of its design.

The aim is to illustrate the architectural and ecological potential of wood, across a range of disciplines, all of which contribute to the environmental impact of using wood, in order to try to answer to the first question. For this purpose, the current knowledge about wood and its use in construction will be presented at multiple scale, in order define its potential to become the material of 21th century and changing the way of design our cities. The environmental impact of wood will be analyzed, through the relationship between wood and carbon dynamics, both inherent to its properties and those involved in timber processing and harvesting. Further, understanding how to exploit the thermal potential of timber, in order to define its environmental relevance as building material.

This, to highlight the ecological potential of this material, that could chart the emergence of a new architecture able to define the wood urbanization.

In the construction practice we are witnessing the attempt of using timber in a way that may require material properties that as yet have not been fully explored. At the same time, the inherent peculiarities of wood, such as its unique combination of thermal, hygroscopic, mechanical and ecological properties, suggest that timber building should be fundamentally different from steel or concrete building and specific architectural design can maximize the potential of this material.

At the smallest scale, we need to understand how the elements that make up the structure of wood contribute to its various properties. At a largest scale, policies that ensure the best environmental outcomes for constructing with natural materials have to be improved. In this regard, an holistic approach in its understanding and use is pivotal to make wood the most of ubiquitous material.

Bridging these two scale together, makes visible the connection between woods, the source landscapes, and wood, the construction commodity. The metabolic framework shows how the social and ecological interdependences of natural environment and built environment are co-produced: the extend metabolic approach in wood design would create a multidirectional dialog among different process at all scales, from production to disposal.

Wood could reshape the cities, but there still are open research questions and areas to develop that would enhance the use of wood in construction, thus we need to amplify the research with an holistic approach in order to increase the already significant potential of the use of timber in the build environment. However, since the use of this material become more widespread and its potential became better understood, a new architecture could emerge and a new urbanism could be developed. And as we often refer to human civilization by the principal materials they employ, the 21th century could become the Timber Age.

Student: Giada Mirizzi

Faculty: Marziah Zad