How design software can lay green building foundations

"You see this wall?" asks Phil Bernstein, award-winning architect and a vice president at design software giant Autodesk, knocking his fist against the wall of the bar at one of West London's swankier hotels. "Walls like this have been built in the basically same way for 500 years – it's about time there was a change."

For Bernstein construction is on the cusp of a green revolution with any number of accepted, but inefficient and environmentally unsustainable, best practices likely to change beyond recognition in the next decade - including how you go about building a humble wall.

"The problem with this wall is that somewhere on this island there is a pile of the leftover slag that was created by the person that honed all this rock to make this wall," he explains. "Now, the most effective and efficient way to build a building is not to build it by hand on site, but to prefabricate it someplace – either in a shed alongside the site in controlled conditions or elsewhere, where you can optimise behaviour and minimise waste."

The ability to prefabricate construction components and effectively create flat-pack buildings may be anathema to more traditional architects, but Bernstein insists that it will make it far easier for architects to design environmentally sustainable, low energy buildings and provide the best means of both limiting the currently gargantuan environmental impact of our buildings and speeding up construction processes.

"[When you can prefabricate a wall] its behaviour and its embedded carbon and use of materials and its geometric relation to the rest of the building will be very precisely understood," he predicts. "And then someone will just come in and snap it into place. It's going to be a different way of building."

For those in the UK whose only experiences of prefabricated buildings are the rather charmless identikit bungalows that were thrown up in the wake of the Second World War to house those who had lost their homes to bomb damage the idea of all new buildings being prefabricated is likely to fill them with horror. But according to Bernstein modern, environmentally sustainable prefabs would be anything but dull identikits. "There are too many variables [affecting each site]," he says. "A building has 10,000 variables and every designer will optimise those variables with a different set of solutions."

Bernstein cites work by Philadelphia-based architects James Timberlake and Stephen Kieran who argue in their recent book Refabricating Architecture that prefabrication could actually enhance the link between customers and architects by ushering in an era of "mass customisation" whereby those commissioning the building can use digital prototypes to more easily customise buildings to suit their needs. "It's like the idea of Levi Jeans scanning your body to get jeans that fit you, but with buildings," observes Bernstein.

However, Bernstien accepts that before such a drastic change in the way all buildings are designed and built can be achieved the construction sector still has a long way to go to improve the environmental sustainability of the processes it already has – a fact which provides a major opportunity for Bernstein's employers, design software specialist Autodesk.

According to Autodesk the key to developing environmentally sustainable buildings lies in the planning stage and, more specifically, state-of-the-art three dimensional design and modeling capabilities.

"The tools we're working on now essentially allow you to build digital prototypes of buildings that allow you to evaluate the prototype in terms of its behaviour," explains Bernstien. "Previously when a designer was working on a building and wanted to know how much energy it would use they would have to send their drawing off to a mechanical engineer who would punch a bunch of numbers into a computer, eventually calculate how much energy the building would use and then send back the results to the designer with a message that it would use too much energy. Now we provide a modeling environment that connects directly to an energy analysis platform so the designer can get realtime feedback on what the energy impact of design decisions are."

Giving designers this insight not only speeds up the design process but makes it far easier for them to optimise the environmental footprint of a building, allowing them to quickly assess how different features improve or damage a sites' energy efficiency.

The same modeling tools can also help limit construction waste, according to Bernstein. "Because constrution materials come in set lengths when you choose a given design the amount of waste you produce from your steel frame or your wall boarding can actually be derived from the dimensional decisions you are making, " he explains. "The waste that gets cut off the end of those pieces of wall board, for example, is just going to land fill – but if the designer has insight into those waste figures they can see that if they make a 10cm change in the design for example, they can save say 16 percent of steel waste or 14 percent of wall board waste."

Like many industries the next step for the construction sector is to go beyond measuring simple environmental metrics such as energy efficiency and waste and start understanding the embodied carbon emissions that result from every decision or purchase. Again, Bernstein is confident modeling software can deliver this information and confirms Autodesk is already investigating ways that incorporate information on materials' embodied carbon into its modeling software.

"At the moment if you use triple glazing instead of single glazing the modeler will say you are using less energy because you are using more insul ation – but what it doesn't tell you is the amount of carbon it takes to generate, deliver and install three pieces of glass instead of one," he explains. "That type of data analysis is an order of magnitude more complicated than where we are at the moment… But we will get to a stage where as an architect I will be able to go to the windows' manufacturers website and download [into the modeling suite] a piece of intelligent data that will not just tell me the geometry of the window but also how much embedded carbon is in it."

Such modeling tools may be prove extremely challenging to develop, but they all but inevitable given the soaring demand for systems capable of delivering green buildings. As Bernstein admits construction is a notoriously conservative industry, but there is a sea change in attitudes towards the environment that defies anything in the sector's history. "Big changes are required given we've been making drawings of buildings for probably 3,000 years," muses Bernstein. " But we really are pushing against an open door. Three years ago the GreenBuild event in the US attracted 2,200 attendees, this year 25,000 people are expected and they had to book a bigger venue - green building is all anyone talks about now."