In October 2016 Paul Bannister, the Australian expert who designed the NABERS Energy rating scheme for commercial offices, came to the UK to review the pilot studies for the Design for Performance project. In his latest blog he discusses how commercial buildings' energy efficiency differs between the UK and Australia .

It is a curse of the Antipodean cultural perspective that we still tend to believe ourselves somewhat inferior to the “old world”. We lack the visible history, we lack the institutions, we lack the pomp. So it is natural to feel that we should look to our colonial forebears for inspiration when it comes to how to do things.

The problem is, of course, that the cultural cringe is precisely that, and often unjustified. So after a week in the UK, do I feel like I have been able to stand proud as an Australian (OK, Scottish born, Kiwi, English-accented Australian) in the hallowed halls of London? The answer is yes – and no.

I’ll start with the negative. The UK doesn’t exactly have a craven left-wing government, but its climate policy makes Australia’s look plainly embarrassing. They have legislatively enacted carbon targets; they have a Climate Change Committee that reviews these targets to provide independent advice on how the country is going towards those targets and what policy directions need consideration; and they have been closing down coal fired power stations as part of their decarbonisation plan (more importantly, perhaps: they have a decarbonisation plan for their grid) and to date have managed to constrain residential energy prices to an on average 2% per annum increase over the last 10 years.  

But then, it’s not that simple. My trip to Blighty was to support a Design for Performance initiative being fronted by London’s Better Buildings Partnership, with widespread industry support. I have spent the majority of the week talking to people about commercial buildings – mainly office buildings – in the light of the undeniable success that is NABERS. And in this light, Australia comes out looking very good. It’s not just that we have NABERS; it is that we leave the UK far behind when it comes to commercial building energy efficiency. To put this in context, work done by Robert Cohen and Bill Bordass puts the average base building energy use in London at around the equivalent of 2.5 stars if compared to Melbourne (as the closest city mainland Australia has to London). Meantime the Australian average NABERS rating is around 4.2 stars equating to 40% lower emissions. If you then look at Melbourne’s best buildings – both of which are rated at 6 stars without Green Power, these generate a less than 25% of the average emissions in London. Bear in mind too that when NABERS was established in Victoria (2000), the average rating there was also around 2.5 stars, so we can reasonably argue that London is a good 15 years behind.

Now, there is a risk that all of this might be some form of data issue unless we can validate that London office buildings are physically less efficient than Melbourne buildings - especially when the UK Part L Energy efficiency regulations have stricter provisions for façades than we do. However, the evidence I have seen so far appears to be that there are indeed fundamental and serious issues with office building energy efficiency in London (and the rest of the UK, by extension) and the reasons for this seem to be bound up in a series of issues that appear to blind – and bind – the UK building industry to poor practice.

Firstly, the UK HVAC market is vastly dominated by fan coils. The precise reasons for this are unclear, but it is possible to speculate that they formed a natural enough step from the radiator-and-opening-window designs of the past. However, in a climate as cold as London they are a significant problem, because they have no free cooling cycle. As a result, on cold London winter days, the city’s chillers are chugging away serving cooling loads. One simulation I have seen for a London project showed a projected cooling energy well in excess of what I’d accept in a building in Sydney or Melbourne, which is an obviously nonsensical outcome. Australia’s default preference for HVAC – the ubiquitous VAV system, which we know can achieve excellent efficiency when driven well  – has a terrible reputation in the UK due to the experience of the first VAV buildings that hit the UK market as a fad in the 1980s and 1990s. These of course were poorly designed and controlled relative to modern practice and are not an indication of what a modern VAV system might achieve in London; that said, it would be foolish to suggest that VAV is necessarily optimal in the UK climate. But surely a system with some form of free cooling is essential for efficient operation in a climate that is undeniably cold by comparison to any populated area of Australia.

Given that we don’t know what optimum design in the UK is, let’s ignore the fan coil issue and assume that these can be made to work with acceptable efficiency – after all, the experience in Australia is that just about any air-conditioning type (including fan coils) can be made to operate at 4.5-5 stars with a bit of tuning, so perhaps it’s true for the UK as well. The far more troubling issue is that the way fan coil systems are commonly implemented in the UK seems to eliminate the possibility that they could be operated efficiently. Issues I have seen on otherwise high-grade office buildings include:

1. The fan coils are often installed, operated and maintained by the tenant, and controlled using a tenant-owned BMS that doesn’t talk to the base building BMS. As a result, the landlord has essentially no way of telling whether a cooling or heating call is valid (or, in some cases, even present) with the result that central chillers and boilers and associated pumps have to run continuously, 24/7, 365 days just in case there is a tenant heating or cooling need, valid or otherwise.
2. Having provided 24/7 chilled water by default, it’s easy to lock this in by letting the tenants connect critical services such as IT room cooling. This is a double whammy – not only does it consolidate the need to operate the chillers continuously and often at loads far lower than they can service efficiently – it puts the landlord at risk of damages if the chilled water loop fails for any reason.
3.  Furthermore, having recast the role of the landlord as a provider of heat and cold (and typically fresh air), some projects go on to see volume control of any these to be a risk, and therefore elect to operate constant volume primary loops for hot water and chilled water (typically serving unvalved heat exchangers to each tenancy) and even unregulated tempered outside air. The latter item is all the more important as the UK norm appears to be to provide design flows of outside air based on 16l/s per person and 1 person per 8m².

So the result is we have some buildings – in apparent compliance with UK energy efficiency regulations – that have 24/7 operation of heating and cooling irrespective of demand, with constant volume pumping and unmodulated outside air. Such buildings have managed to institutionalise severe levels of inefficiency into design and operation and to a large extent lock out the opportunity to tune away inefficiencies in operation, due to the lack of controllable components and the lack of visibility of fan coil operation. Furthermore, these issues have been normalised throughout the market to the extent that it is difficult for anyone – inside or outside the UK industry – to challenge them.

My experience of talking with contractors, consultants and owners indicates that all of these stakeholders can see the problems with the current approaches but that they feel somewhat powerless in the face of an HVAC paradigm they don’t feel they can control. As is often the case, everyone points to the tenants and their agents; no-one wants to lose a potential tenant because they have failed to meet expectations. And yet, it is also likely that the tenants themselves are as much a victim of this paradigm as everyone else. After all, it is hard to believe that it is more cost-effective for the tenant to control and maintain fan coils while also paying a share of excessive heating and chilled water system operation than for them to pay a share of a common building-wide maintenance contract and energy costs of an efficient primary plant. And that’s without considering the costs associated with the installation and demolition of fan coils for their tenancy, even if on a long lease.

Thus it is this institutionalisation of inefficiency that the UK will have to address if it wants to improve the performance of its office building stock. The introduction of a voluntary performance based rating system like NABERS would be an excellent first step in this process, as it would bring the consequences of these decisions into light. A softly-softly approach is needed as huge changes in perspective and practice are needed from tenants, owners, designers and contractors; being too abrupt is likely to cause stiff resistance. Along with this, changes are needed to Part L – the energy efficiency section of the UK Building Regulations – to get HVAC energy efficiency regulation up to the same standard as façade performance. A difficult road lies ahead, but one with potentially enormous benefits for the UK economy and environment.

Thus, returning to the issue of Aussie cringe, we have a lot to be proud of in what we have achieved in office building energy efficiency and a good deal to teach the UK and much of the rest of the world about what we have done. We also shouldn’t get too cocky about it – it is perhaps as much good luck as good management that has created the circumstances under which we could achieve the results we have. One only needs to look at the limited HVAC efficiency progress in sectors outside the office sector to realise that we too have our institutional issues. We may be winning the battle of office building energy efficiency, but there is a long way to go before we have won the broader war on inefficiency in buildings in general; and victory in that battle is essential if we are to meet the existential challenge of climate change.

This articles was originally posted on LinkedIn here.