A holistic approach to life cycle design

What does life cycle design entail?

Nigel Justins: It is a holistic approach to treating the earth’s precious resources – water, energy, and materials and managing what we’ve got with care, working with what we have and using no more than we need. It’s as simple as that.

Steve Fox: As designers, we can influence the process by identifying the objectives, refining the methodology for using our natural resources, and engaging productively with our stakeholders to deliver more sustainable designs that deal with climate change. We need more buildings and infrastructure to support our growing population, but this shouldn’t be detrimental to the planet’s ecosystems. We play a vital role in achieving a healthy balance.

Nigel: Yes, and importantly, making sure things don’t slip through the cracks. We might see a project that’s strong in some aspects of the design response, but life cycle design considers all of the critical strands to ensure nothing is left behind.

Steve: We focus on themes of water, energy, and materials and how we implement better day-to-day solutions to address these key sustainability themes. Our purpose is to engage with clients and stakeholders, educate people, and develop tools to gain better insights and analytics for optimising our designs and reducing carbon.

Let’s talk about water. What are the main approaches to minimising our impact and consumption of water systems within buildings?

Nigel: Reduce first, then reuse and recycle – this is the mantra we can apply equally to energy, materials, and water. With water, when it comes to conserving and reusing, we need to grow our understanding of greywater systems, even blackwater systems, and ultimately look at going off the grid.

Steve: There are intelligent systems we can specify, like waterless devices, air-cooled building systems instead of water-cooled systems, efficient appliances, and smart metering to gain more insight into water use.

Nigel: I think there’s certainly a lot of potential in smart sensors and monitoring for energy and water – it’s often just a matter of making the users aware of the technology. Almost everyone has access to a digital device these days; for example, there could be a dashboard or an app that tells you your building’s water utilisation is running at a higher percentage than usual. So that would be popular. People would be asking, “Are we losing water? What’s going on?” Building owners are getting into this a lot more; empowering occupants needs to be encouraged.

Steve: Emerging from the catastrophic bushfire season of 2019/2020 and the drought that impacted NSW, we were put on strict water restrictions. This will be an ongoing trend, and I’d hope that people will pay closer attention to their water usage. We could incorporate smart building controls into our designs to encourage this awareness.

Nigel: Yes, and the other part is how buildings are sited and what we can do in the broader context to minimise water demand. Taking a water-sensitive urban design approach, for example, where we capture the water runoff from hardstand areas instead of putting it into the stormwater system and using it to water the landscape, reduces the urban heat effect, creating a cooler and greener space.

There’s a lot more we could do. Much of the technology to support water conservation already exists. It’s been tested and proven but not universally adopted. I think we’re going to start seeing a far greater take-up. Conversations are needed early on to incorporate water-saving techniques into the project, and this is where our sustainability framework can help trigger these early conversations with the client.

Looking at building systems as a broader idea, how does the water use in buildings impact their surrounding environments or communities? How can we reduce this impact?

Steve: When building hard surfaces, we’re reducing our land’s naturally porous surface area and increasing stormwater loads. One of the problems with this is the contaminants that stormwater collects and deposits into our waterways. So, we see the emergence of porous surfaces replacing traditional collection systems on our public laneways, and it’s encouraging to see designers considering permeability to promote a return to nature.

Nigel: It’s one of the significant issues relating to water management, but there are things we can do. We can maximise the permeability. While introducing a certain amount of hardstand is often unavoidable, permeability can still be realised in both the ground and the roof plane. Buildings with green roofs have multiple benefits; they improve stormwater management and help to insulate the building below.

We can better manage stormwater by looking at bio-retention and bio-filtration. And, where the water returns into the system, we want to have healthy, not contaminated, water in the system. We have the issue of capacity, the knock-on effect being flood risks and contamination. If we think of existing land as a verdant green plane, and then we come along and build on it, we have to think about how to return it to its original green footprint.

How easily can renewable energy sources be incorporated into a building’s life cycle design?

Steve: We start by looking at where technologies provide the most value. We know that photovoltaics need orientation to the sun. So, while façade panels could potentially have built-in photovoltaics, their orientation is not optimal and so not particularly efficient. Perhaps future technology will change that, but current technological limitations and site-specific context will limit the capacity of on-site renewable energy generation.

Nigel: I think that’s right, Steve. In the early 2000s, I worked on the first refurbishment project in New South Wales to get a Green Star rating, an office building on Pitt Street. We considered the Green Star credits for renewables on that project, but achieving that on an existing building on a tight urban site was always going to be challenging. We looked at solar panels on the façade, which at that time was in its infancy as an emerging technology, and it didn’t stack up. We also looked at wind turbines and calculated that we would have needed about 50 of them on the roof, which was unachievable because of its location in the CBD. So site context is key.

Steve: From a digital perspective, we spend a lot of time on façade optimisation. For example, with sun shading, we need to balance sought-after views with the ability to reduce solar gain. We use computational tools to demonstrate that balance. It’s encouraging to see this testing be adopted in the early phase of design.

Are suppliers transparent about making sure their supply chains are sustainable?

Steve: We have a huge responsibility to properly source materials. For instance, with an increase in the development of mass timber production, we need to be sure we aren’t creating a monoculture. We should be mindful to ensure that products and materials come from trustworthy sources, interrogate the industry’s greenwashing and challenge suppliers by looking more deeply into supply chain claims rather than simply accepting their word for it.

Nigel: Yes, when specifying products, you might go directly to a supplier’s website and select their most “green” product. Sometimes the benefit can be marginal; it’s just less harmful than the other products in their range. It’s best to go through credible sites such as Eco-Specifier to specify with confidence.

Some suppliers are doing great things with recycling. The carpet manufacturer Interface, for example, takes back its old carpet tiles to be recycled. They recognise that in a high-churn industry of interior fit-outs, they can make an enormous difference. We need more companies like that, and I’m sure we will now that we recognise the need for circularity in our design thinking.

Steve: We saw a recent example of a cladding manufacturer, Equitone. They’re acutely aware of the high-water consumption needed in manufacturing processes, so their product has a high recycled content. They avoid mixing in contaminants which would prevent them from being reused down the line. They also focus on durability to increase its life and reduce the need to replace broken panels.

When we meet suppliers, we need to ask hard questions about their products. If suppliers hear that there’s enough interest in specifying products with genuinely strong eco-credentials, I think we’ll start to see some real-world changes.

How can material selection reduce the energy consumption in buildings?

Nigel: The short answer: massively. Think about the thermal mass of the building, how the building envelope absorbs the sun’s energy and then releases it.

The conventional approach in Australia has been to put bricks on the outside and lightweight skin on the inside. It makes more sense for the lighter skin to be on the outside and the heavy thermal mass on the inside for much of our climate. We have seen that applied successfully in some buildings, but they tend to be the exception. I think we can do more to understand the logic behind this approach.

We also need to better understand how we balance airtightness and breathability, noting the Passive House approach from Germany, which is gaining popularity in Australia. It eliminates all air leakage from a building, creating a tightly sealed envelope with controlled ventilation. It’s different from the so-called ‘passive design’ approach, which is predicated on the notion of breathability, relying on cross-ventilation to help moderate the temperature from the harsh Australian sun. You need to understand where the breezes are likely to be by considering the micro-climate. So, you’ve got this sort of polarisation at the moment.

Steve: Would these design approaches be applied with consideration of the local climate? For instance, would a designer lean to one approach in far-north Queensland and take a different design approach in southern Australia?

Nigel: Indeed, the cooler the climate, the more compelling the case is for the Passive House approach. But in tropical and perhaps even subtropical zones, intuitively, you’d think having that openness and cross-ventilation make more sense.

Steve: Yes, a relatively new concept to designers is the impact of embodied carbon. At Architectus Digital, we’re exploring digital tools and embodied carbon databases, both locally and overseas, to make sure our early designs are responsive. That’s where we see the big impacts of a building’s carbon footprint.

We’re also partnering with The Footprint Company to get greater insight into carbon benchmarking. As a result, we’re beginning to understand what individual materials contribute and how our designs compare to typical carbon benchmarked building types.

We’re trying to understand more about the numbers and where those benchmarks should be for the industry. We’ve discovered a significant upfront carbon contribution to a project that shouldn’t be overlooked. No matter how efficiently a building operates, we must look at the whole life carbon to get an accurate picture, including embodied carbon.

Nigel: Yes, and for that reason, there has been a shift towards retrofitting first, if you can, rather than demolishing and rebuilding. Whereas in the past, buildings were knocked down to build a green building that could be justified on operational energy savings, we now appreciate it’s important to look at the embodied energy that would be obliterated to rebuild. We are becoming more informed about this and more considerate of embodied or upfront energy.

Steve: Perhaps we can even start to go carbon positive.

Nigel: That’s the holy grail.