We didn’t design for this (but we can retrofit for it)
作者
Bill Grover
查看个人简介New buildings are fantastic! And they are wonderful to work on - but in many ways refurbishment projects are more challenging and interesting. They are almost always inherently more sustainable than a new development too, because a large proportion of the existing embodied carbon is retained and given decades more useful life.
In recent years, many retrofit projects have focused on public areas, aesthetics and user experience amenities such as better lobbies, end-of-trip facilities for cyclists and social spaces. This has particularly been a priority in the post-lockdown market as commercial building owners scrambled to ensure they could retain tenants and make the office an attractive place to return to.
But there’s a much bigger threat than Covid that retrofits need to start addressing, and that is the escalating impacts of climate change. As discussed previously, a technical due diligence ahead of asset acquisition should now include a resilience assessment, and the same is true for planning and implementing building refurbishments, repositioning and retrofit.
Code minimum is not fit for a changing climate
For decades the property industry has generally designed and delivered buildings to code minimum. Unfortunately, those standards have resulted in too many homes, workplaces and public places that are energy-guzzling assets reliant on mechanical heating and cooling to stay somewhat comfortable.
Planning has also focused largely on the individual asset, as if they exist in splendid isolation, rather than setting standards around connectivity and the impact on the surrounding urban fabric. For example, the calculations for an individual building may look terrific in terms of optimised passive solar, but they may stop being valid the moment someone puts a great big new tower next door.
The legacy of business-as-usual development is that we have a huge tranche of buildings in almost every city that are not designed to function effectively in the changing climate. Ideally, if we want to protect lives and the functioning of our communities, retrofits for resilience should be undertaken for the majority of buildings across every sector.
For example, we have thousands of apartments that are not designed to protect inhabitants from extremes of heat without air conditioning – and many of these buildings have no backup power in the event of grid failure or load trimming brownout events. The same is true of many schools, hospitals, retail centres, public buildings and office assets.
Heat is not the only risk that we need to retrofit for – flash flooding from extreme rainfall, rising sea levels, increased severity of bushfires, the cyclone zone extending further into sub-equatorial latitudes, increased risks from social unrest - the IPCC reports are clear that there are many dimensions to climate change consequences.
How to make a start
There are several ways to peel this banana, starting with thinking about how we can put buildings and communities together in different ways to improve adaptation and resilience.
We can create resilient and efficient buildings if we really put our minds to it, but the interesting challenge is putting the initiatives and ideas together as a value proposition and ensuring they are affordable.
Basically, you take a distressed, possibly empty building, you may reskin it, you can resurface it, you make it super-efficient, you ensure there’s a way to naturally ventilate, increase natural daylight and add strategic shading where solar heat gain will be most problematic, and it is good as new if not better.
Adding end of trip facilities is important because then you've got tenants who want to come to work, or in other property classes, you’ve created options for active pedestrian or cycle travel.
It's also much better for our cities to improve what we have rather than sprawl ever-outwards because we are getting the maximum use from existing infrastructure.
We have all the technology, and we know all the things we need to do to get existing buildings to be more efficient and effective. We can quantify buildings in terms of how long the backup power would last for, how long it would stay comfortable for without air conditioning for, how long the water lasts in the backup water tank.
These are all basic measures that can be done around longevity in the event of something failing.
A team approach is essential
From a technical viewpoint, revitalisation and retrofit projects also involve a different dynamic in the project team compared to a new development. Success relies on bringing together the engineering, architecture and facilities management experts to plan and implement the work plan, rather than decisions devolving down from a head contractor.
It’s a collaborative effort, and the knowledge of the people who operate and maintain the building is a necessary addition to the process. The technical knowledge of building services engineers and sustainability experts is also vital in the early planning stages, as their expertise is needed to interpret the current building performance and create the pathway for improvement.
Addressing the data gap
But there is one tricky part and that is the statistical case – what data do we have to justify resilience upgrades? What used to be true in the way of “1-in-100 year” risks is no longer the case – these events are now occurring sometimes in consecutive years. We’ve seen historical heat records broken every year for the past decade in almost every major city.
But – what data do we use to balance the cost of NOT improving resilience with the cost of retrofitting and the return on retrofitting?
The likelihood of an event and its severity and consequences – a risk register and risk matrix – are an important part of making the business case, if the moral and ethical case is not sufficient.
So, for a retail, commercial, mixed use or public building, we might need to put some numbers against the cost of downtime or disruption. For the residential sector it’s more arm’s length, perhaps data around the costs of emergency services response, impact on insurance premiums or risk to the financial sector from home loan defaults.
Ultimately, we need to be challenging what we think we know about the kinds of buildings we develop and where we develop them, because the statistical reference points and assumptions we've used to inform our planning and construction codes and standards aren't relevant anymore. They need to be reassessed, and especially so when planning, designing and delivering a retrofit.
That means if we are investing in improving a building, retrofit projects must target the performance that will be fit for purpose in 2030, 2040, or 2050, not the minimum code of today.