I am Arup’s global skills leader for...
Cities across the globe are facing increasing demand on resources – resources they need to function. However, technology is playing an important role providing more efficient systems that reduce the impact of the built environment. For example, there has been a massive change in lighting: moving from tungsten bulbs to LEDs, something which has generated considerable energy and cost savings. These lamps are reasonably easy to install as the existing electrical supply systems can be used.
We design buildings with lifetimes that far exceed the speed of change of the technology used to service them. When engineering a new building, as well as considering what technology is available now, we should also consider how the development of technology might result in new solutions that could be retrofitted within the lifetime of that building.
As engineers, we need to keep an eye on new advances in technology. Sometimes we encounter a new technology that may not be immediately suitable. This might be due to its readiness, its cost or the client’s perception of risk. (Many clients do not want to be the first to adopt new solutions.) The ease of retrofitting a new technology is often a barrier to its adoption in existing buildings but with some forethought there can be simple and cost-effective ways to accommodate it.
One example is the increasing demand for potable water in cities. By 2050, it’s predicted that London will to need to find an additional 500 million litres of water each day and that water charges will continue to rise. One technological solution would be to reuse non-potable water such as rainwater and greywater for purposes that do not require high-quality water. However, long payback periods make these systems unattractive for now.
One barrier to the adoption of water reuse systems will be the complexity of retrofitting them to existing buildings. For buildings under construction today, it’s possible to include infrastructure such as non-potable water pipework routing, and set aside space for treatment and storage equipment at a much lower cost than retrofitting non-potable water systems at a later stage.
As water becomes more expensive and water resources become scarcer, foresight will allow us to have buildings ready to accept these systems in a cost-effective way. This is already happening in the desert city of Tucson, USA, where all new housing was effectively mandated to include provision for future greywater re-use and more recently in San Francisco, USA.
We need to consider low-cost ways to enable easy retrofitting of new technology that can be reasonably anticipated but may not be ready yet, allowing buildings to be ‘fitted for but not yet fitted with’. By giving thought to future-proofing our buildings we will make our cities more resilient.