A new ICE insights paper explores no- and low-build alternatives that could satisfy the demand for infrastructure.
To build or not to build?
That is the question that civil engineers and infrastructure decision makers need to be asking themselves more often.
Low- and no-build solutions are alternative options to always building new assets to fulfill an infrastructure need.
They've gained popularity over the last 20 years as they can provide a wide variety of benefits for people and the planet.
However, they've mostly been implemented on a project-by-project basis.
The ICE's latest insight paper outlines ways that low- and no-build solutions can be implemented at a larger scale.
Benefits of low- and no-build solutions
Most low- or no-build solutions can reduce carbon emissions.
Other benefits for people and the planet can include:
- Delivering different benefits to multiple groups. For example, creating an artificial wetland can purify water while also providing a park for people or a habitat for wildlife.
- Being cost-effective by reducing the need for large upfront investments in new infrastructure and being cheaper to maintain.
- Helping preserve natural ecosystems and support biodiversity by protecting species’ habitats.
No-build solutions
No-build solutions are ways to solve infrastructure needs without building new assets, such as bridges, roads or buildings.
Repurposing
Repurposing infrastructure is another way to meet community needs without building a new asset.
In Manchester, UK, the Castlefield Viaduct sky park is giving Mancunians a place to connect with nature and get together.
Castlefield Viaduct used to carry heavy rail traffic in and out of the city, but it’d been out of use since 1969.
Repurposing it has breathed new life into the structure while serving local communities.
And there was no need to build – one half of the park was planted with trees, flowers and shrubs, while the other was left untouched, showing how nature has reclaimed the structure.
Blue-green infrastructure
As the example above, introducing plants and water (blue-green infrastructure) can help to meet community needs.
For example, sustainable urban drainage systems (SuDS) seek to imitate natural drainage, and often use plants in doing so – these are known as landscaped SuDS.
Bioswales are a staple of landscaped SuDS. They’re shallow channels where polluted water can sit and be purified by vegetation and soil as the water gets absorbed into the ground.
By building bioswales you not only help reduce things like surface flooding, but you clean the water naturally, too.
Operational changes
No-build solutions may require engineers and policymakers to think outside the box.
For example, with an increase in need and desire to travel, airports may struggle to cope.
While some may think expanding the airport is the only solution, there's a variety of options airports could try first.
For example, optimising the queuing system, improving signage, rearranging the airline locations, using smart technology, and more.
Low-build solutions
Low-build solutions are those that require minimal construction to be done.
Nature-based solutions
As with blue-green infrastructure, nature-based solutions (NBS) can cut down on the need to build.
NBS are actions or measures inspired by, supported by, or copied from nature.
For example, in the Apalachicola Bay in Florida, USA, there’s a segment of a highway (that’s part of a hurricane evacuation route), that had been suffering damage due to coastal erosion.
The regional planning council collaborated with WSP USA to put in a NBS that consisted of establishing an intertidal marsh by introducing oyster reefs.
This reduces the effect of wave energy on land, preventing the sea from breaking down the shore and protecting the area from rising sea levels.
Unlike humanmade coastal defences, oyster reefs can repair themselves if they’re damaged by waves.
Circular economy
The goal of a circular economy is to reduce waste and maximise resources.
This involves taking measures to repurpose infrastructure to reduce the need to build new assets.
It also includes using non-virgin materials (those that have already been in use) in construction and having dismantling and recycling units.
France’s ‘Covid cycle lanes’ are a good example of circular infrastructure.
To provide an alternative to public transport while curbing car use during the Covid-19 pandemic, the French government put together a €120 million budget to turn roads into cycle lanes.
This low-build solution was a success, with 600 people taking up cycling and the government supporting the repair of 1.7m bikes.
Tried-and-tested ways of incorporating low- and no-build solutions in infrastructure planning
The ICE’s research identified four examples:
1. Using no-build as a baseline
In 2023, an independent panel appointed by the Welsh government highlighted the importance of considering a no-build approach to road planning, which has led to less construction overall.
Specifically, it encouraged policymakers to only consider investing in new road schemes for four purposes:
- to further cut carbon emissions;
- to reduce driving-related casualties;
- to adapt roads to the impact of climate change; and
- to support people in using transport sustainably.
If the Welsh government implement these recommendations, it will commit to building fewer roads, helping them achieve sustainable development for future generations.
2. Outlining ‘do minimum’ options
Extending the life of existing infrastructure requires much less time and investment than new-build solutions.
Australia’s ‘smarter’ approach to assessing infrastructure options incorporates low- and no-build options.
Infrastructure Australia’s assessment framework for projects encourages policymakers to consider different ways to meet infrastructure needs.
Alongside options to invest in building new infrastructure is a list of ways to ‘better use’ existing infrastructure.
These include changing timetables to better distribute passengers across existing transport services or encouraging people to work from home to reduce congestion and carbon emissions.
3. Set aside funding
The German government has adopted a low-build approach using nature-based solutions to combat the climate crisis.
It created a €4 billion action plan to outline how climate change will affect Germany and what nature-based measures can help protect communities.
In Singapore, the government has adopted nature-based solutions into its long-term planning frameworks.
These include the 10-year Green Towns Programme, led by the Housing and Development Board.
The programme uses “natural, semi-natural and man-made green and blue features” alongside ecological engineering methods to reduce energy consumption, recycle rainwater and encourage urban cooling.
4. Strike mutually beneficial partnerships
Sharing or leasing infrastructure assets is one way of embracing a no-build approach in strategic infrastructure planning.
If carried out successfully, sharing infrastructure enhances its use, while cutting the cost of operating it.
This tactic is mostly seen within the energy and telecom sectors.
In Turkey, several telecom operators signed an agreement in 2018 to lease fixed electronic communication infrastructure, which includes things like cables or wireless towers.
This helped boost internet access across Turkey, delivering the country's National Broadband Strategy and Action Plan.
Barriers to no-build and low-build solutions
While low- or no-build solutions can offer long-term benefits for economies, communities, and the environment, they haven’t been taken up widely due to a range of barriers.
The main obstacle to their implementation is a lack of understanding and evidence of their benefits.
Because of this, policymakers often choose to build new assets.
Moreover, there’s no universal standard for the long-term use of low or no-build solutions. And, it requires different ways of working.
This means there’s a lack of clear direction on how to best integrate them into strategic infrastructure planning.
Civil engineers, as creative problem-solvers, have a key role in helping to address these challenges and support the wider use of low- and no-build solutions.
Working with nature
- How policy can unlock the potential of nature-based solutions
- Nature-based solutions: respite for our elderly during heatwaves and beyond
- The barriers we need to overcome to build in harmony with nature
- How can engineers use nature to protect people from flooding?
- 5 lessons learned from blue-green infrastructure delivery