Post Occupancy Evaluation: operational performance of a refurbished office building

This blog was written by Dr Michelle Agha-Hossein BEng (Hons), EngD, Sustainable Building Consultant for BSRIA's Sustainable Construction Group

This blog was written by Dr Michelle Agha-Hossein BEng (Hons), EngD,
Sustainable Building Consultant for BSRIA’s Sustainable Construction Group

My Engineering Doctorate study aimed to investigate how and to what extent office building refurbishment can help to improve occupants’ satisfaction, perceived productivity and well-being while optimising building’s operational performance.

A case study approach and a “diagnostic” post-occupancy evaluation style of framework were adopted in this study to evaluate the performance of a recently refurbished 5-storey office building in detail and find opportunities to reduce the gap, if any. The study divided the workplace’s environment into three categories: ‘physical conditions’, ‘interior use of space’ and ‘indoor facilities’. Employee surveys and interviews revealed that interior use of space was the most important aspect of the building influencing occupants’ perceived productivity, well-being and enjoyment at work (happiness) while the improvement of the indoor facilities had no significant effect.

The study also concluded that issues with the physical conditions (such as noise and temperature) causes negative effects on perceived productivity but improving this aspect to a higher level than it is required would not necessarily increase perceived productivity. In contrast, improving the interior use of space aspect of a workplace would increase employees’ perceived productivity proportionally.  These results, however, should be considered with cautious as employee’s satisfaction surveys and interviews revealed that employees’ levels of expectation might have affected their levels of satisfaction with their new work environment.  This could cause some bias in the results of buildings’ performance evaluation. A potential

Old working environment

Old working environment

solution to this issue is to measure occupants’ expectations for their future workplace at the design stage to try to fulfil these expectations as much as possible. How well the new work environment met occupants’ expectations is another factor that should be measured at the post-occupancy stage.

It was also noted that the occupants density at the building was low at the time of the study (17.7m2/person) and that the space was not fully and effectively utilised and more than 50% of the workstations were often not in use. The link between improving space utilisation and the building’s energy consumption as well as its occupants’ perceived

New working environment

New working environment

productivity and well-being merits further investigation. These results are important in the projects where increasing productivity is a key and the budget is limited.

In terms of energy performance and CO2 emission, it was revealed that the actual emission of the building was three times more than the design target. Most of the low cost opportunities identified to reduce the gap were related to the building management and control as well as occupants’ behaviour. I will be doing a webinar very soon on simple energy efficiency tips related to building management and control and occupants’ behaviour. Watch BSRIA’s website for more details about this webinar. 

Global BEMS Market set to Approach $7 billion by 2020

This blog was written by BSRIA's Henry Lawson

This blog was written by BSRIA’s Henry Lawson

If I could point to a market which is already worth some $3.5 billion, or 3 billion Euros, and which is growing globally at well over 10% per annum, at a time when growth in building automation is a fraction of that, I suspect that many investors and industrialists would bite my hand off. This is the industry that we explore in BSRIA’s newly updated report BEMS Opportunities.

Even Europe, which currently accounts for almost half the current Building Energy Management Systems (BEMS) market, is growing at around 10%, while North America has been growing faster, and the rest of the world substantially faster still.

BSRIA forecasts that the global BEMS market will almost double, to more than $6.8 billion by the year 2020. This impressive growth is set to occur in spite of numerous obstacles and uncertainties. This is partly because the factors driving this growth differ from one region to another.

In Western Europe, gas prices almost doubled between 2005 and 2013, while at the same time major economies like Germany became increasingly dependent on import of gas from politically sensitive countries like Russia and the Gulf states, raising the spectre of uncertain supplies.

While the rise in electricity prices has been less dramatic, Germany faces the huge task of fulfilling its commitment to

henry dec2shut down all nuclear power generation by 2022, and the UK faces similar challenges as its ageing, coal-consuming and CO2-spewing power stations reach the ends of their lives, with the ghost of Christmas back-outs rising like a Dickensian spectre to haunt the business and political worlds.

This, and increasingly aggressive environmental targets, at national and EU level, mean that even a Europe which has been in or near recession for more than five years continues to invest in energy efficiency. At the same time, there are signs that organisations at all levels are beginning to understand the full potential of BEMS to save money while meeting obligations and improving the brand.

In North America, the pressure of energy prices has been less relentless, especially since fracking of shale gas has got underway. The movement towards environmental regulation has also been patchier – often varying at local and state level, and has faced more opposition. At the same time, the proportion of energy consumed by office buildings has been rising inexorably at a time when energy used in such areas as transport, industry and homes has been either stable or falling, placing office buildings firmly in the sights of those wishing to make savings. North America also benefits from the plethora of firms developing innovative energy management solutions in both the USA and Canada.

In the rest of the world the picture is extremely varied, from developed countries like Japan and Australia with widespread adoption of BEMS, to major emerging economies like China, where energy has hitherto been seen as rather less of a problem but where the pollution associated with fossil fuels is becoming more pressing.

This growth presents huge business opportunities but also as many gauntlets thrown down. The mainstream building automation suppliers are all active, unsurprisingly, given that the two are so genetically interlinked that building automation was originally widely referred to as building energy management. They can offer the benefit of relatively easy integration of energy management into the building’s wider functioning.

Against this, as virtually every device, appliance and component of a building becomes capable of generating and communicating data, the advent of big building data has opened huge opportunities both to enterprise data and IT suppliers and to an army of smaller newer suppliers of advanced analytics, allowing building managers to predict and pre-empt problems that degrade a building’s energy performance.

Some of these new entrants will fall by the wayside, especially given the level of overlap between many of the offerings, others will be ripe for take-over, but a few are likely to emerge as major disruptive players. In our report we identify the leaders and challengers, along with the niche players and some of the most likely acquisitions. As always, there is an implicit conflict between the move towards integration on the one hand and the desire for innovation on the other, and we look at some of the standards that are emerging to address this.

The prize is most likely to go to companies that can combine innovation in new technologies, and understanding of how a building’s occupants interact with the building, with a deep-seated understanding of how buildings function. This report should help to shine a light on who will be left holding a torch for others to follow if and when the lights really do threaten to go out.

This is the industry that we explore in BSRIA’s newly updated report BEMS Opportunities.

Smartening up the City

This blog was written by BSRIA's Henry Lawson

This blog was written by BSRIA’s Henry Lawson

There are some leaps in technology that seize the mind and imprint themselves indelibly on the memory. There can hardly be anyone over the age of 50 who doesn’t recall their grainy view of the first man on the Moon, and people who are quite a bit younger will remember when, say, paying a bill or booking a holiday online was still a novel experience.

There are other changes which, while they are already having far more impact on our lives than the Moon landings, seem to have crept up on us, almost by stealth. The advent of the Smart City looks very much like being one of the latter.

The Seminar Smart Cities and the Internet of Things, which BSRIA attended on 16th July, helped to flesh out some of these. One key factor is of course the sheer all-encompassing variety and complexity and scale of a modern city, as reflected in the technology required to support it. This was underlined by the presentations on the range of “smart” cities, from major building consultants, to companies working closely with utilities, to data analytics companies.

This points to a pluralistic approach where different companies collaborate, each contributing their own particular skills, rather than one where a mega-corporation tries to orchestrate everything.  As one speaker pointed out, the smart car alone is likely to involve motor manufacturers, battery and power specialists, grid utilities, digital IT specialists, and the advertising and public relations industry (interestingly, two of the three first people I spoke to represented public relations companies). And that is before one gets on to the subject of the role of city and national authorities.

While the seminar focussed, understandably, on the elements that comprise the “Internet of Things”, making up ‘the nuts and bolts’ of the smart city, it also convinced me that we need to pay more attention to the wider social, political and economic context.

What makes a city smart? Given the combination of complexity and subjectivity, that is always going to be a hard question to answer. Nonetheless a group of academic institutions did rank 75 smart cities across Europe based on the “smartness” of their approach to the economy, mobility, the environment, people, living and governance.

When I measured the ranking of smart cities in each country against that country’s average income, I was struck, but not that surprised, that there was an almost linear correlation between a country’s wealth, and the ranking of its ‘smartest’ city. Thus at one extreme Luxembourg, easily the richest country in Europe, and second richest in the world, was also judged to have the smartest city. Lowest ranked was Bulgaria, which also had the lowest per capita income of all the countries on the list. Most other countries were in a ‘logical’ position in between.

Smartening up the city

One can of course argue whether smart cities are mainly a cause or a consequence of a country’s wealth. Up until now I suspect it is mainly a matter of richer countries being able to afford more advanced technology, not least because the relative economic pecking order has not changed that much in the past 25 years, i.e.. since before the smart city era really got underway, indeed if anything the countries on the bottom right of our chart have been catching up economically, which could be why countries like Romania, Slovakia and Slovenia are doing better in the smart city stakes than their income might suggest.

Luxembourg is of course unusual in one other significant respect. In terms of size, and population, it is about the size of a city, and is politically and economically very much focussed on its eponymous capital city. This raises a question sometimes posed in other contexts: Is the “city state” making a comeback, and could this have a bearing on the development of the smart city? In this respect it surely speaks volumes that Singapore, probably the closest entity to a city state in the modern world is not only highly productive economically but frequently cited in the history of the smart city, going back to the days when it pioneered road pricing more than a generation ago, and one of the cities mentioned in this seminar.

If you are laying down the guidelines for a smart city then there are clearly advantages in having an authority with the resources and powers of a government, combined with the local knowledge and accessibility of a city.  But given that splitting up the world into hundreds if not thousands of new ‘city states’ does not look like a viable option, what can be done to create a framework in which smart cities can flourish in a way that is responsive to their citizens’ needs?

Even in larger countries, the Mayors of major cities are often heavyweight national figures, enjoying wide ranging  powers. This applies to cities like New York, Berlin, Paris and, more recently London. One of the most interesting developments in Britain is the growing recognition that while London is already in effect a global economic power, other cities have been struggling to keep up. While this problem long pre-dates the smart city, it speaks volumes that, with a general election due next year, all of the major parties are now committing to giving more powers to major cities outside of the capital, possibly with more directly elected mayors.

Given the nature of democratic politics there is still no guarantee that this will happen, especially given governments’ traditional reluctance to hand over power, but with Scotland likely to enjoy greater autonomy even if it votes to remain in the UK, the pressure to devolve more power to cities and regions in the rest of the UK will be that much greater.

Even this would not of itself promote smart cities, but it would mean that city mayors or leaders seeking to promote and coordinate smart city developments, and companies and interest groups looking for partners, would have much more powerful instruments within their grasp.

BSRIA’s Worldwide Market Intelligence team produces an annual report into Smart Technologies. To find out more go to our website

Best & Worst Practices Please!

Julia Evans, BSRIA Chief Executive

Julia Evans, BSRIA Chief Executive

BSRIA recently held a workshop on behalf of DECC identifying priorities to promote low carbon heating and cooling in non-domestic buildings as part of the development of its low carbon heat strategy.  Attendees were drawn from both the Young Engineers and Energy and Sustainability BSRIA networks.  Personal thanks to AECOM’s Ant Wilson for chairing the event.

It was a busy day.  It recognised that both new and existing buildings have a pivotal role in reducing greenhouse gas emissions, and by 2050 one of the key requirements will continue to be how we provide heating and cooling.

BSRIA’s Peter Tse and Ian Orme both gave excellent presentations which drew on both good and poor practices identified from more than 50 independently assessed case studies.  These, I felt, answered the questions “what does good practice look like”, as well as “what are the consequences when its not followed”.

The workshop session resulted in many suggestions as to priorities for the future.  There were a couple which caught my eye.

In response to the suggestion that one of the priorities for DECC should be identifying independently assessed best practice and developing exemplars of new technologies, a number of delegates felt that instances of “bad practice” were even more helpful.  It seemed to me that a priority for at least a part of the audience was to know what to avoid doing.  Perhaps this reflects the industry’s receptiveness to messages about risk, and that we often learn most when we make mistakes.  The emphasis on “independent assessment” also resonated.  Many have become sceptical about instances of self-identified “best practice”, and BSRIA’s independent guidance on what works, and what does not, is there to assist the industry do things better.

Another of the workshop themes was on “skills shortages”.  After many years of recession, construction companies have euphemistically “right sized”, and this means that we have lost a lot of great talent from the industry.  Now that there are green shoots of recovery in construction, there is already talk of an exacerbated “skills gap”.  This gap makes it even more challenging for the industry to deliver buildings which meet the needs of their occupiers and where innovation is required to help tackle climate change, and meet the UK’s commitment to “zero carbon” and “very low energy” buildings. This reminded me of another of BSRIA’s strengths – training provision.

BSRIA's 2014/15 Training Brochure

BSRIA’s 2014/15 Training Brochure

Finally there was an astute observation that our recent quest for low carbon buildings has meant that we have worried less about the efficient use of energy, with the net outcome that we can end up with an EPC A rating for carbon design, but a DEC G rating for energy in use.  The move to policies that move us to buildings which are both zero carbon and nearly zero energy use will hopefully remedy this, although I suspect this particular journey may contain further unintended consequences before we reach that goal.

The workshop identified many requirements if we are to create environmentally conscious buildings that meet user needs, and importantly maintain these elements over the life of the building.

BSRIA’s mission remains to “make buildings better”.  As part of my role, I’m listening to our members and the industry what they expect from BSRIA.  I’d like to extend this offer to you, so if you have ideas about BSRIA’s future role, please send them to me: Julia.evans@bsria.co.uk.

To learn more about the BSRIA workshop you can download all the presentations from our website. 

Design Fine Tuning?

 

Julia Evans, BSRIA Chief Executive

Julia Evans, BSRIA Chief Executive

BSRIA has been involved in many recent projects including an independent assessment of the realised performance of low energy / environmentally conscious buildings.  This includes projects associated with the Technology Strategy Board’s Building Performance Evaluation (BPE) programme.

The emerging results for more than 50 non-domestic buildings have now been analysed by BSRIA to look at what works well, and when things don’t, why this is the case.  It’s always difficult to generalise based on such a diverse building stock, ownership profile, procurement route, supply chain capabilities, and operational approach, but its clear that in many of the buildings there is a significant performance gap between design intent, and realised performance.  Analysis of such data is always a challenge.  How does one attribute, for instance, any shortfall in performance between the specification, design, construction, commissioning process, and to operational issues such as sub-optimal energy management and / or changes in operating regime such as an extension in occupancy hours.

However one lesson inferred from the analysis is that with some low carbon (and / or energy) buildings one of the unintended consequences is that sometimes the building has been finely “tuned” to minimise carbon (and / or energy), and capital costs at the expense of the building’s resilience in the face of, say, changing patterns of use or internal gains.  Put simply, if a building has been engineered to reduce energy and or carbon for a particular set of operating conditions, and one way of achieving this is to simply size ventilation, and air conditioning plant in line with those conditions, what happens if say internal gains increase as a result of higher occupancy loading?  In practice it is found that some environmental designs lack the flexibility to cope with changes in business use because of limitations built into their design.  This happens with more conventional buildings, with the difference for environmental buildings being more pronounced because the design in many cases is more finely “tuned” as we move ever closer to “near zero”, or “very low” energy / carbon buildings.

BSRIA’s experience identifies many of the good practices required to ensure environmental buildings work well, and also the impact of poor practice.  Overly sensitive design is one cause of poor performance in practice.  So the question is why do some clients and their design team include a sensitivity analysis to design services and size plant so as to ensure resilience, whereas others adopt an approach best characterised by “lowest capital, highest environmental ranking, never mind about actual performance in use”?  The likely answers are complex.  Those found by others like Latham and Egan come to mind for some instances: informed clients recruit supply chains who know their business, and both understand implications of design decisions; post-occupancy-evaluationanother is the chasm which can often occur between those who specify, procure, and lease buildings, and those who occupy and manage them.  Perhaps a third is that once a building has been occupied, too seldom is thought given to how the building will actually work in the face of changes in occupant requirements.

The question for BSRIA is how we can provide a steer and guidance to our members and the industry as to how best to ensure that we build the next generation of environmentally sensitive buildings to be even more resilient in the face of likely changes those buildings will face over their lifetime.  A building which has a very low carbon and / or energy design use, but which fails to provide a productive environment in the face of foreseeable changes in operating conditions can’t really be described as “sustainable”.

This blog was written by BSRIA’s Chief Executive, Julia Evans. For more information about BPE you can visit our website or visit the TSB’s BPE pages where you can look at case studies and methods of BPE (you may need to register to access these). 

Refrigeration Part 1 – Choosing the right refrigerant

Salim Deramchi, Senior Building Services Engineer at BSRIA

Salim Deramchi, Senior Building Services Engineer at BSRIA

Refrigerants are a key component for air conditioning and refrigeration. Since the 19th century there have been many refrigerants developed and used but none of them has as yet become the industry standard.

As an industry we should not consider reducing F-Gas emissions as just complying with legislation to meet government set targets, but reducing them will also have a positive effect on operating costs.  We can make cost savings through efficient operation and we can also help enhance market reputation by being more environmentally friendly.

To have a good understanding of this we need to look at:

  • Available refrigerant types
  • Our selection criteria
  • How we evaluate the available refrigerants

Traditionally commercial businesses have been using R12, a CFC, and R502a CFC/HCFC. In addressing the ozone depletion problem, most manufacturers have adopted either R404A a HFC blend or R134a. However, both are potent greenhouse gases (Nicholas Cox).

So the industry needs to look at future solutions which might be natural refrigerants, although some design change might be required on the equipment used. The following refrigerant replacements all require system and operational changes to current practice:

20140213_132647_resizedIsobutane (R600A) is a hydrocarbon , and hence is flammable. The thermodynamic properties that are very similar to those of R134a. Isobutane presents other advantages, such as its compatibility with mineral oil and better energy efficiency and cheaper than that of R134a. The use of isobutane requires minimal design changes, such as the relocation of potential ignition sources outside of the refrigerated compartment. Operational changes will also be required.

Propoane (R290). With a boiling point of -42C, propane is an excellent alternative to R22 as it requires similar working pressures. An added advantage is that except for added safety measures because of its flammability, virtually no design change is required in systems when switching from R22 to propane. The combination of its good thermodynamic and thermophysical properties yields systems that are at least as energy efficient as those working with R22. The use of propane is increasing in countries where regulations allow it.

Ammonia (R171). Ammonia has been continuously used throughout modern refrigeration history. Despite its numerous drawbacks, it is toxic and flammable in concentrations between 15.5% and 28% in air. It is not compatible with copper, thus requiring other materials of construction. Its thermodynamic and thermophysical properties also yield very efficient refrigeration systems. Because of its acute toxicity, stringent regulations apply for ammonia systems, which require close monitoring and highly skilled engineers and technicians.

20140213_132339_resizedCarbon dioxide (CO2) is not a new refrigerant. Rather, it was ‘rediscovered’ in the early 90’s. The use of carbon dioxide as a refrigerant has gone back well over a century. Its application was abandoned in the mid-50s, with the widespread use of the CFC refrigerants, which were more efficient, more stable and safer. Due to its low environmental impact, low toxicity and non-flammability, CO2 is now regaining popularity from refrigeration system designers when an alternative to fluorocarbons is being sought. (Ahmed Bensafi and Bernard Thonon)

So there are alternatives on the market and technology development is tackling this issue it is now up to the designers and operators to specify something new to move the industry forward. With F-Gas regulation 2 coming we need to get ahead of the game.

We have tried to cover some of the available refrigerants seen in the market and we will be evaluating and discussing the selection criteria in our future blogs.

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