Thursday, 7 December 2017

Transforming a Slough waste-recycling centre using Green Infrastructure

As Green Infrastructure Design Challenge 2017 winners we’ve been invited to share our experience of being involved in the competition which was part of Green Sky Thinking Week 2017, so here goes ….

We are Louise and Stephen Handley, Landscape Designers at Amey plc. I must admit Stephen ‘fell’ upon the competition whilst ferreting through the Landscape Institute website. We don’t usually have time to enter competitions, but the brief for the Green Infrastructure Design Challenge corresponded closely with a project we were working on for Amey, and as designers anything that allows you to play with a project is welcome!

The live project was a planning application to convert a piece of land near our offices to an additional car park, extra spaces being needed because our offices are merging with the local authority and an increase in staff will follow.

The site is currently green (e.g. grass) and acts as a flood defence for the adjacent stream - the area being in a 1 in 100 chance of annual flood zone. Our proposals aimed to lessen the impact of a hard surfaced car park on a sensitive site and improve the space’s function as flood defence. We integrated rain garden clusters, swales and porous surfacing into the scheme.

The Challenge brief called for measures to be proposed for both the interior and the wider public realm, so we integrated the exterior treatment of the building with the external space and then connected this to the new car park with a ‘green walk’ which incorporated tree planting and a dense hedge.

Although this was a design competition, we approached the brief as if it were a realisable project, experimenting with ideas for improving the existing offices, whilst considering how future development of the building and site could incorporate Green Infrastructure measures and new technology.

The Green Infrastructure Adaptation Strategy we developed for the site used first-hand experience from current occupants and the CIBSE Design Summer Year (DSY) and Test Reference Year (TRY) files to help us guestimate the adaptation measures which may be needed from 2020. The issues we highlighted in the strategy provided us with principles for the design, such as:-

 internal comfort and building fabric
 external comfort and building facade
 drainage, attenuation, and flooding
 landscape features
 landscape innovation

Our office building is a ‘peach’ of a poor environment for people to work in. Sandwiched between a waste transfer station and a sewage pumping station, and bordered by the M4, its construction and aspect ticks all the boxes for overheating in the summer, poor insulation, poor air quality, ventilation etc. We knew that the introduction of vegetation into the offices would benefit the occupants in terms of wellbeing and air quality, but we also knew that the lack of natural light in some of the deeper corners of the building would be a problem in terms of growing. This problem led us to looking at hydroponic growing with artificial light (no… not that) and in turn we discovered a company called Plant-e, who have developed and patented a way to produce light and energy from living plants.

‘Fantastic!’ cried the enthusiastic designers, ‘we’ll just grow stuff vertically under red and blue LED lights, powered by plants!’ ‘Errmm …’ cautioned the scientists at Plant-e, ‘not so sure about that, but we could certainly experiment with the idea.’ So we had interesting conversations about fitting PMFCs (plant microbial fuel cells) into hydroponic units and storing solar power from the roof in batteries which could power the fuel cells, and we developed conceptual vertical units to grow edible plants which could be tended and eaten by the office staff.

Given that the building is to house more staff and their comfort and wellbeing should be considered as important to productivity, we decided to take out a section of the front elevation and install an atrium where the additional much needed sunlight is filtered by screens of plants, both outside and inside. The external walls and roofs are clothed in vegetation which will improve both summer and winter insulation issues and act as attenuation for heavy rainfall, and this in turn will be directed to rain gardens in the ground plane. Large scale tree and hedge planting will address heat island, air pollution, and shading issues – all of which are current problems.

Click here to view our winning entry.

Our challenge experience

Competition work stretches your thinking beyond your comfort zone, this one is no exception.
We have gained valuable knowledge which has now become part of our design approach for all new projects.

We have made interesting new contacts – notably Plant-e in the Netherlands, Shelley Mosco, research assistant for the Landscape and Environmental Research Group at Greenwich University, and of course Anastasia Mylona, Research Manager at CIBSE and the ARCC network.

Flexibility in the site selection allowed participants to interrogate their own chosen building and public realm, and then allow the brief to guide how to approach the site.

The CIBSE Analysis formats - Climate Change Risk Assessment, Adaptation Strategy etc were invaluable in helping to structure the information that we needed in order to develop the design.

Thank you and goodbye for now.

Click here to find out more about the CIBSE / UKCIP Green Infrastructure Design Challenge and how to enter for the 2018 competition.

Thursday, 19 October 2017

Plan - Do - Check - Act

Many UK businesses are looking to increase efficiency and reduce energy costs. Whether as part of an overall corporate strategy, a route to organisational efficiency or a key focus of a cost or carbon reduction drive, monitoring and managing your energy use effectively makes sound business sense. But what steps can companies take to manage their energy use? CIBSE takes a look at ISO 50001 and the business opportunities associated with it.

ISO 50001, the globally recognised energy management standard developed by the International Organisation for Standardisation, is the key tool in that process.

It provides a framework for effectively managing the energy that an organisation uses in its premises. It helps organisations understand where they are using energy, how that energy use can be managed effectively, and how consumption and costs can be controlled into the future.

The standard is effectively a framework to:

  • Develop policies and approaches for the more efficient use of energy
  • Help set organisation targets and objectives 
  • Use data to better understand and make decisions about energy use
  • Monitor, review and improve on an ongoing basis.

Conformity with ISO 50001, confirmed through official third party certification, can be a route to a range of business benefits. It allows organisations to demonstrate responsible and efficient energy management, and can provide returns in energy and cost savings, and employee engagement. It can also give organisations an important business edge, in public relations and satisfy tender requests for responsible energy management.

Steps to managing your energy use
Constant monitoring allows companies to review and develop their energy management processes

ISO 50001 follows a plan-do-check-act process, with organisations seeking certification needing to:

  • Plan – Create an energy plan with baseline indicators of energy performance, strategic and operative energy objectives and action plans
  • Do – Implement the plans, targeting improvements
  • Check – Check that the plans being put into action are proving effective, by monitoring, measuring, and comparing results with the initial objectives
  • Act – Review performance in regular reporting, to optimise and improve energy related performance and the energy management system.

The business opportunities

ISO 50001 is a relatively new standard, issued in 2011, but its uptake is growing rapidly. According to an ISO survey, almost 12,000 ISO 50001 certificates were issued in 2015, up 77% on the preceding year. It is now applied by major brand names in manufacturing industries, retail, financial services, communications and many other business sectors in the UK and internationally.

The standard is suitable for any business in any sector, although some organisations may be able to drive greater benefits than others, with more significant energy users having the greatest potential to make savings. That doesn’t mean, however, that the standard is only viable for major energy users, as it can form part of an integrated approach to energy management, and provide broad opportunities for business improvement.

How organisations can make the most of the ISO 50001 opportunity

The most popular way to demonstrate conformity with ISO 50001 is via third party certification. CIBSE Certification is an independent body, with UKAS accreditation to certify to this standard, and is backed by the recognised authority and expert building services knowledge of the global engineering body, CIBSE.

CIBSE Certification is UKAS accredited for the certification of ISO 50001

Want to know more?

CIBSE Training provides a course designed for energy professionals who are looking to gain an in-depth knowledge of the ISO 50001 Energy Management Systems (EnMS) standard, and also those who are tasked with designing, implementing and maintaining an EnMS that complies with the ISO standard.

Find out more:

CIBSE Certification operates a register of Low Carbon Consultants, all able to provide authoritative, expert advice on managing energy use, increasing efficiency and helping organisations implement an ISO 50001 compliant energy management system. The register contains more than 1,200 names, located across the UK, all of whom have undertaken an assessment to demonstrate their competence.

CIBSE Certification can also offer non-accredited certification for:

ISO 9001 Quality Management System
ISO 14001 Environment Management System
ISO 18001 Health and Safety Management System

To find out more and to check out the register of Low Carbon Consultants, visit the CIBSE Certification website:

Friday, 1 September 2017

Leading lights

Local authorities have cottoned on to the cost benefits of LED lighting in our streets, and in government owned buildings across their portfolio. But to what extent can LEDs help squeezed budgets? Society of Light and Lighting Secretary Brendan Keely takes a look.
Just under a year ago, the UK Government affirmed its commitment to the 5th Carbon Budget which binds it to a target of 57% cut in carbon emissions by 2032 – with a view to an 80% cut by 2050. This is a refreshingly ambitious target, but according to Dr Hywel Davies of the Chartered Institution of Building Services Engineers (CIBSE) it will mean that the Government must maintain all of its current climate policies and find further ways to make cuts if it is to stand any chance of hitting this goal. This means the Government is going to have to get creative in order to eke out savings above and beyond what it is already doing.
Last year I wrote that a great way of cutting down on emissions is to target the 180,000 government owned buildings in the UK, two-thirds of which are run by local authorities – encouraging them to switch to properly designed and specified LED lighting solutions in order to save money and carbon.
LEDs can save councils money on energy costs in contexts from streets to stadia
Since that article was published, local authorities across the UK have been rolling out LEDs en-masse for their environmental and budgetary benefits, in new builds, as part of retrofits, on motorways and in street lighting. With most local councils aiming to replace all of their sodium-based street lighting with LED alternatives gradually over the next decade, LED will soon be a fixture just about everywhere.
Much has been made of the great efficiency savings that can be made with LED technology – since the year 2000 LED lights have become ten times more efficient and can boast far longer lifespans than even the most advanced fluorescent lights. Combined with other measures to boost efficiency, such as controls systems, LED solutions can represent a step-change in the efficiency of a building’s lighting – up to 80% savings in some cases.
The maths also looks good from a lifetime perspective as well – a combination of a long life, energy efficiency and low maintenance costs are a great asset to facilities managers worried about the overall cost of a new technology. In this vein, they are also easy to integrate into existing energy management systems: They can easily be set to dim automatically or turn off altogether to reflect the number of people in a room, the time of day or the time of year. This applies on the scale of a single room, a whole building, a stretch of road or a whole town, and can save money without jeopardising safety because their efficiency actually increases when they are dimmed.
Local authorities can make savings across their building portfolio
The energy and carbon savings possible with LED lights are well documented, and local government has bought into their potential on a large scale – but simply seeing LED as a cheaper, newer replacement for fluorescent lights that tick a few green boxes seriously underestimates their other benefits.
At the recent CIBSE Technical Symposium, Ashley Bateson of Hoare Lea observed that only 1% of the cost of running a business is energy related while 9% is rental and a massive 90% is staff costs. The health and wellbeing of the occupants who live and work in a building is hugely important to a company’s bottom-line, because staff absence and illness costs more than any amount of inefficiency, but it can’t be easily measured on a meter so is often overlooked.
The effects of the built environment on health are numerous, complex and touch just about every element of a building. Just sitting next to an open window can reduce a staff member’s sick days by as much as 6%, for example, and higher CO2 concentrations can reduce student’s cognitive performance by 72%. Lighting is no exception to this.
Artificial light is known to affect the human circadian rhythm

The most well-known application of lighting to wellbeing is in the human Circadian Rhythm - the biological processes that regulate our waking and sleeping hormones. Since researchers discovered that this cycle is greatly affected by light, when less light enters the eye it tells our brains that it’s dark and time to sleep or when brighter time to wake up, much has been made of the role of artificial light in this process. Too much blue light in the evening can fool the body into thinking that it’s day time – thereby interfering with the natural sleep cycle.
Daylight remains the most effective means of keeping the Circadian Rhythm in check, but with the advent of LED lights that can mimic a range of colours and intensities it is increasingly able to replicate natural changes in the spectral distribution of the light to mimic natural light, to the extent that it can offset the damage to mood and sleep cycles linked to prolonged periods in doors. The light changes colour during the day – from colder blue light in the afternoon when we need a boost to be active to warmer colour temperature light in the evening when we’re resting. In the winter months when it gets dark early, it could even mean the difference between a well-rested workforce and a tired one.
The versatility of LED technology also allows designers to create bespoke solutions that create a balance between the light’s usefulness and its impact on health. Obviously a workplace needs to be well-lit enough to be safe and functional, but the impact of lighting too intensely from above can be anything from eye pain caused by glare or flicker. It can even make a room harder to see, by creating dark areas where there isn’t a balanced light distribution. Using control systems in conjunction with LEDs, it is possible to reduce these problems by setting light intensity to match the local requirements, and allow office users to choose their own settings for comfort. Even the ability to adjust lighting levels gives building users a psychological boost that lowers absenteeism and increases productivity.
LED light can be produced in a variety of colours to mimic the day/night cycle
LED lighting is crucial here because they not only produce light, but the right kind of light for a workplace environment. There are numerous studies that link brighter offices with increased productivity, motivation and enhanced wellbeing. The flexibility of LEDs not only allows us to light the room more effectively, but with the right kind of light to ensure the lease disruption.
While the savings attributable to energy efficiency caused by the switch to LED lighting is great for local authorities, it really only scratches the surface of what is possible for the whole range of publically owned buildings – from workplaces to leisure facilities, schools, hospitals and libraries. A 1% increase in productivity or health of employees can far outweigh all of the savings achieve through efficiency.  But it’s all down to how LEDs are implemented and deployed within buildings.
In order to ensure that the technology is properly utilised so that it is as effective and efficient as possible, local councils will have to ensure that it is professionally designed as part of a wider strategy that bakes efficiency into the design of their buildings. It’s not as simple as replacing one technology with another like-for-like: it needs to be properly designed and installed by an engineer or designer following industry guidance, such as that produced by the Society of Light and Lighting and the Chartered Institution of Building Services Engineers, to be as effective as it can be, and ensure that works harmoniously with the building, the occupants and the other systems in play.

Friday, 25 August 2017

New horizons

With the launch of the new CIBSE UAE region, CIBSE is preparing for a rush of new activity in the area from all over the built environment. We take a look at some of that activity with Society of Public Health Engineering's UAE representative Andy Russell, who reports on the launch of their UAE chapter

After months of planning a SoPHE UAE launch event was held at the Dubai World Trade Centre Club on Level 33 overlooking downtown Dubai on the 8th March. SoPHE UAE was conceived in October 2016 with Andrew Russell of Hilson Moran, Simon Lewin of WSP Parsons Brinckerhoff and Keith Perry of Polypipe taking lead roles for SoPHE in the region. The partnership and collaboration between the three individuals and their organisations will be key to raising the standards of PHE design and profile of SoPHE in the region.

As a landmark in the UAE this iconic building opened in 1979 and the 39-storey Sheik Rashid Tower is featured on the 100 dirham bank note. As Dubai’s first skyscraper it remains a pioneering symbol of international trade and is home to many leading international corporations including CIBSE UAE. A fitting venue for the SoPHE UAE launch evening.

The Sheik Rashid Tower, Dubai's first skyscraper
The evening started with addresses from CIBSE UAE Chairman Raef Hammoudeh of KEO IC who spoke about the status of CIBSE in the region and SoPHE Chair Steve Vaughan of AECOM who spoke about the role of SoPHE as a society.

Steve also gave an update on the growth of SoPHE since 2014 with nearly 900 members in 10 regions together with the training and educational initiatives being led by the society. The importance of the Young Engineers Group was also discussed and how the society are looking to develop the engineers of the future.

As expected the launch event was well attended mainly by non-members indicating great potential for the future of SoPHE in the UAE so the evening focussed on the benefits of joining CIBSE, Membership options and what SoPHE can offer in the region together with outlining future events within the region.High on the agenda for the new region is a UAE Technical Group to produce technical bulletins and training specifically tailored for UAE PHE design to improve the standard and consistency of PHE design across the region.  

Polypipe gave a short presentation to show how they support the society in terms of training and education for public health engineers in the region.The evening concluded in the local McGettigans bar (another Dubai landmark!) with live music, food and drinks courtesy of Polypipe.SoPHE would like to thank Polypipe for their continued support of the society together with their involvement and funding to make SoPHE UAE happen this year.

Friday, 11 August 2017

A business plan

British Land has won four CIBSE Building Performance Awards in the last five years, most recently for energy efficiency improvements to its property portfolio. With entries open for the 2018 AwardsSara Kassam, CIBSE’s Head of Sustainability Development, sets out to understand why energy efficiency is so important to the property company.

When British Land won the Client Energy Management category at the 2012 CIBSE Building Performance Awards the property company had achieved a 15% reduction in like-for-like landlord energy use across its office and retail properties and was targeting a 20% reduction in energy intensity per square metre across its entire portfolio.

Five years on and British Land won the Test of Timecategory at this year’s CIBSE Building Performance Awards for continued energy performance. It won this accolade for a 40% portfolio-wide reduction in carbon intensity (scope 1 and 2) relative to 2009 levels, a 38% reduction in landlord energy use and its 2020 target to cut energy intensity by 55% - all while increasing focus on the wellbeing and productivity of people in its buildings.

York House in London is part of the British land portfolio 
British Land’s impressive energy performance improvements are the result of its Energy Efficiency programme. Over the last four years, the programme has resulted in occupiers saving a total of £13 million, cut carbon emissions and helped position British Land’s portfolio to meet forthcoming climate regulations.

The programme came about in 2009 in response to emerging occupier interest in energy efficient spaces, anticipating future demand.  What’s exciting at the moment, having shown we can deliver on energy efficiency, is occupiers’ growing interest in other aspects of sustainability, particularly wellbeingsays Matthew Webster, justifying his job title as Head of Wellbeing and Futureproofing at British Land.

“The work we’ve done on smart management of energy has given us a unique understanding of how data can provide management insights and be used to improve the environment for the people in the building,” he says. “At a basic level this includes optimising lighting levels, air quality and temperatures for both efficiency and wellbeing; we’re now applying the same proactive approach we used on energy to enhance our buildings for wellbeing and productivity”.

The British Land team collect their Test of Time Award at the
2017 CIBSE Building Performance Awards
Eight years on and Webster says he’s still having discussions with potential occupiers about energy. “I’ve had lots of conversations before people move into a building about how it is going to perform from an energy perspective,” he says. However, energy efficiency is now “a hygiene factor” that occupiers simply expect rather than a differentiator:  “Our proactive approach to energy efficiency has contributed to the attractiveness of our buildings, helping attract occupiers and keep existing occupiers with us,” he says.

The increased focus on energy is also about British Land facing increased scrutiny from commercial investors with ethical and environmental requirements forming part of their investment criteria. “There is increasing scrutiny and requirements from investors to report on portfolio efficiency via things like carbon disclosure,” Webster explains.

So what has British Land done to reduce its landlord energy consumption by 38%? It is a combination of active energy management, transparency on energy consumption, up-skilling of building engineers and energy efficiency retrofits.

The digital strategy around energy management was an important part
of British Land's success

British Land uses Broadgate Estates to operate and manage its buildings. “It is the Broadgate Estates teams managing our buildings who’ve made the biggest difference by changing their culture so that every property manager and engineer prioritises energy efficiency and wellbeing in everything they do,” Webster explains.

The 55% target energy intensity reduction across the portfolio was selected as being a target that was “challenging” but at the same time realistic for property teams he says. “We will be able to get to it; since 2009, we’ve got a much better understanding of what can be achieved,” he says.

Interestingly, Webster says that saving energy is not simply a matter of return on investment. “There is lots that we can do that doesn’t need capital invested, once smart metering is installed it is about managing the building as efficiently as possible”.

Almost 90% of British Land’s entire portfolio is now covered by smart meters. “Our property teams have access to energy data in 15-30 minute slots so that they can see when plant is running when it shouldn’t be and take necessary action,” he says. “In the past systems would have turned on a chiller at 5am regardless of whether it is needed, now we manage what we’ve got in a more efficient way,” he adds. In addition, off-site specialists also monitor data for offices to identify additional energy efficiency opportunities.

British Land have access to up-to-the-minute energy data via smart meters
which cover 90%of their portfolio
Other free and low-cost interventions introduced by British Land include:
    Installing daylight sensors to reduce lighting levels in line with increased daylight
    Ensuring equipment and lighting are always turned off outside working hours
    Eliminating heating and cooling plant conflicts by ensuring there is a dead-band between when the heating turns off and the cooling kicks in
    Increasing the use of ‘free’ cooling during the day when outside temperatures are below internal temperatures and also using outside air at night to remove residual heat from offices.

To see how well it is performing against over developers, British Land benchmarks with the wider industry through initiatives such as the Better Buildings Partnership and, surprisingly, Australia. “We’re particularly interested in Australian buildings because they have NABERS [National Australian Built Environment Rating System] and compliant buildings seem to be performing better than the UK market in energy performance,” Webster says. In fact, over half of all Australian commercial office buildings are now covered by the scheme and, on average, have increased energy efficiency by 12%. Importantly from British Land’s perspective, the  Australian market is now rewarding investment in energy efficient design for buildings with a high NABERS rating by higher asset values and lower occupant vacancies.

British Land’s benchmarking initiative is not confined to existing buildings, it also sets out to benchmark its new buildings to make these as energy efficient as it can. For this exercise, British Land uses CIBSE Technical Memoranda 54 to set the performance targets for its new buildings. This guidance enables the design team to evaluate operational energy use more fully, and accurately, at the design stage “You do the modelling with the design team and then you use those benchmarks to give the designers an energy target to work towards,” explains Webster. Currently TM54 is being used on eight new buildings. “Once we’ve achieved 80% occupancy we’ll invite the design team back in for a conversation with the buildings operators for them to see how well the building is performing in operation”. Webster says that the meeting is not to criticise the designers but to give them the opportunity to learn what has worked well and what could have been improved upon in the design.

Buildings in Australia have seen dramatic improvements in energy consumption
after introducing the NABERS scheme
In its drive to continuously improve energy efficiency British Land has also started to trail on-site energy generation. At St Stephens shopping centre in Hull, for example, over 1100 photovoltaic panels were installed on the centre’s roof. These generate enough clean electricity to meet a third of the electricity demand in common areas cutting annual electricity bills by £30,000 and generating a return on investment of 14% over 25 years and saving 3000 tonnes of carbon.

Similarly, an air-source heat pump was installed at 350 Euston Road in 2014. This has cut gas use by 85% and achieved payback within a year. This has the additional benefit of saving occupiers £60,000 a year and has cut temperature-related complaints by 40%. The switch as also cut annual carbon dioxide emissions by 410 tonnes and reduced the need for boiler flues, which also helps to improve local air quality.

Looking to the future, British Land already has plans in place to meet its 55% energy intensity reduction target. Through the Energy Savings Opportunity Scheme audits across the portfolio, it has identified further initiatives that could deliver an additional £3.7m net savings and optimise environmental conditions. “This now forms a key part of our roadmap to achieving our reduction target,” Webster says.

To find out more about the CIBSE Building Performance Awards and how to enter for the 2018 competition (deadline: 15 September 2017) visit

Friday, 28 July 2017

Bright future

With record June temperatures and the launch of CIBSE's new TM59, the built environment is starting to get tough on overheating. Sara Kassam, Head of Sustainability Development at CIBSE, takes a look at a paper presented at this year’s CIBSE Technical Symposium set out to evaluate both the overheating risk and suggest appropriate mitigation strategies

Retrofitting homes and building new homes with high levels of fabric insulation, is a key tenet of the UK government’s carbon emissions reduction strategy. But, while a well insulated home may require very little heating in winter, without minimizing solar gains and without the implementation of sufficient ventilation strategies, in the summer, high levels of insulation can increase the likelihood of a home overheating. 

Research by the University of Sheffield, based on computer modelling, has shown that with increased levels of insulation overheating is a problem, one that is set to get worse under the impact of climate change. However, the research also shows that with a few simple mitigation strategies a well-insulated home will enable the occupants to benefit from enhanced winter comfort without the risk of overheating in summer.

Computer modelling can predict overheating based on a variety of factors
The findings were presented in the paper Evaluating Overheating Risk and Mitigation Strategies in Low Energy Houses in the UK: Two Sheffield Case Studies, at the recent CIBSE Technical Symposium. For the study the researchers selected two detached homes in the Sheffield area. One was a new-build home built to Passivhaus standards. The other was an existing home, which had been retrofitted to Zero Carbon standards. 

Evaluation of the likelihood of overheating in both homes was undertaken using Passive House Planning Package steady-state energy balance software based on the East Pennines climate dataset with altitude adjusted to reflect the actual location. Future climate datasets used for the analysis were developed by the University of Exeter for both the 2050s and 2080s, under the high emissions scenario, based on the UKCP09 climate projections. 

Overheating metrics were based on the PHPP maximum default temperature of 25℃, which must not be exceeded for more than 5% of the time to ensure good comfort levels. If the 25℃ threshold is exceeded for 10% or more of the time then, under PHPP additional summer heat protection will be necessary.

Results of the modelling for the retrofit house:
Pre-retrofit, in the current climate, no overheating is predicted. 
With the building retrofitted to Zero Carbon standards overheating occurs for 2% of the time
By the 2050s, the Zero Carbon standard building will overheat 8% of the time
And by the 2080s, overheating will occur 13% of the time

Results of the modelling for the new build house:
In current climate, PHPP predicts overheating will occur for up to 32% of days annually.
By the 2050s, that figure will have risen to 52% 
And by the 2080s, 57% of days will be above the overheating threshold 

The researchers suggest some appropriate mitigation strategies for the retrofit house: 

Modelling predicted the new build house would overheat on the majority
of days by the 2080s

Reducing wall insulation
The results suggest that overheating could be reduced by 2%, in both the 2050s and 2080s climate scenarios by reducing wall insulation from Passivhaus to Building Regulations standard. Reducing roof insulation levels made no improvement on overheating frequency in the 2050s and only a 1% improvement by the 2080s.

Opening windows for night-time ventilation to provide 1.5 air changes per hour suggested overheating frequencies could be within the 10% figure in the 2050s. However, by the 2080s the same night cooling strategy would lead to a 12% overheating frequency.

Internal and external shading will reduce the amount of direct summer solar gain, reducing overheating risks. In the retro-fit house, internal shading reduced overheating frequency massively to keep it within 10% for both the 2050s and the 2080s scenarios. External permanent shading was also modelled with similar results.

For the new build, external vertical blinds with horizontal slats were most effective. External blinds eliminated overheating in the current climate and reduced overheating frequency to 10% and 14% in the 2050s and the 2080s future climate scenarios.

Strategies from solar shading to natural ventilation can be used to mitigate the
risk of overheating in the future
Reducing transmitted solar energy
In the retrofit building the glazing g-values (the value of solar energy transmitted through the glass) was reduced from 0.62 to 0.3, reducing solar energy permeability from 62% to 30% produced a significant reduction in the overheating frequency so that in the 2050s overheating would occur 2% of the time, rising to 5% in the 2080s. In the new-build, the g-value was reduced to 0.25, which decreased overheating frequency to 3% in the current climate context. However, reducing g-values was less effective in the future climate scenarios and led to an increase of space heating demand.

Combined strategies
For the retrofit house, it was found that night-time ventilation combined with temporary internal shading and permanent external shading eliminated overheating risk entirely in the 2050s, while in the 2080s overheating only occurred for 2% of the time. For the new build house a combination of reducing glazing g-values and adding external blinds eliminated overheating in the current climate and reduced it to 3% in the 2050s climate context. However, in the 2080s, there will still be 12% overheating frequency.

The findings show that while low energy housing standards such as Passivhaus can lead to reduced space heating demands the modelling also showed that over time the changing climate would lead to a higher frequency of overheating occurrences. However, the modelling also showed that with appropriate overheating mitigation strategies overheating risks could be predominantly eliminated in current and future climate scenarios. A robust solar heating mitigation strategy for houses in Sheffield would be: internal or external shading, night-time ventilation and reduced glazing g-values.

Friday, 14 July 2017

Heat rises

In this month's #Build2Perform podcast, CIBSE PR and Communications Executive Matt Snowden spoke to CIBSE's Dr Anastasia Mylona about what's inside the newly launched TM59: Design methodology for the assessment of overheating risk in homes

New guidance published by the Chartered Institution of Building Services Engineers (CIBSE) aims to address the causes of overheating in homes, as the UK enters a summer that could be the hottest since 1976.

Addressing what the industry had identified as a gap in its knowledge, CIBSE have created the new Technical Memorandum 59: Design methodology for the assessment of overheating risk in homes (TM59) in order to set a standard by which overheating can be assessed using a consistent methodology.

The new TM59, available now as a free download and officially launched at University College London on 28 June, has created a common approach that will see the whole industry consistently apply the same methodology. This approach may be crucial in the years ahead, with the MET Office reporting that the eight warmest years in the UK since 1910 have occurred in the last 14.

Further reading

TM59 on the CIBSE Knowledge Portal
The TM59 press release 

Friday, 7 July 2017

30 years and counting

Celebrations of CIBSE Australia and New Zealand's 30th birthday are in full swing this year, with a Presidential visit and a cocktail reception already under their belt. CIBSE ANZ Business Development Manager Sharon Pestonji takes a look at the highlights.

It’s been 30 years since the Australia and New Zealand region of CIBSE was inaugurated. The faces of the ANZ committee have changed, but the passion driving our region forward is still as relevant as ever. In times where the pulse of change beats fast, CIBSE continues to provide industry with the guidance and training for safe, comfortable and efficient buildings.

It is not prudent to forge forward without looking back to recognise your roots, CIBSE ANZ has published 30 Years and Counting, to mark the occasion. The 30th Anniversary publication is a collection of monumental projects, photographs and memorabilia documenting the history of CIBSE in the region, plus a look at the present and future of the building services industry in Australia and New Zealand. This publication will be sent to all CIBSE ANZ members and is available electronically to browse.

The publication '30 years and Counting' will be sent to all CIBSE ANZ members
Sponsored by Fantech, AG Coombs and Norman Disney & Young, a highly successful 30th Anniversary Cocktail Function, held on the 15th June 2017 at Melbourne’s Sealife Aquarium celebrated the occasion. Guests included CIBSE members, industry leaders and dignitaries, including CIBSE President, Peter Y Wong who travelled from Hong Kong to attend. In his address, he recognised and thanked the contributors to the success of the growing region. 

“30 years is a long time. Over the years we have had many triumphs and challenges. The achievements of CIBSE ANZ are of course a sum of many contributions from loyal volunteers, members and supporters.” 
- CIBSE President Peter Y Wong

The function was also an opportunity for CIBSE and Engineers Australia presidents to re-new the long-standing agreement for the Mutual Recognition of Engineers. This agreement simplifies the transfer of equivalent Australian and International titles and qualifications for members. Read more

CIBSE President Peter Y Wong addresses the CIBSE ANZ reception

The function also hosted the first ANZ region-wide competition for Student of the Year and Young Engineer of the Year awards, recognising innovative ideas of students and the significant contribution of young engineers to building services. Finalists were flown from around the region for the winners’ announcement on the night. Thai Nguyen, a Mechanical Engineering (Hons) Student of the University of New South Wales and Simon Green, a graduate Building Services Engineer from Arup specialising in mechanical engineering design took the top prizes. Read more

In 2016, the CIBSE ANZ Committee were instrumental in establishing an external Advisory Panel to help the development of CIBSE ANZ, reflecting the region’s ambitions to grow and focus on the engineers of the future. Their efforts secured the first full time appointment in the 30-year history of CIBSE ANZ - Earlier this year, Sharon Pestonji was appointed and immediately tasked with business development for the institution. Last week CIBSE enthusiastically welcomed Tim Spies of Norman Disney and Young to the panel, who continue to work on a 2020 vision of expansion and growth for the institution in the region.

Engineers Australia President John McIntosh exchanging signed
mutual recognition documents with CIBSE President Peter Y Wong
Looking to the future, Paul Angus has been elected as CIBSE Australia and New Zealand Region Chair at the ANZ Regional Committee meeting on 16th June 2017.

Friday, 30 June 2017

Gothic revival

As part of our new series about the future of the UK's building stock, we take a look at the past. Making new homes sustainable is already a massive issue, but with one in five houses more than 100 years old, bring them up to standard is key to meeting sustainability targets. CIBSE Technical Director Dr Hywel Davies takes a look at one such project.

If the UK is to meet tough carbon reduction targets for 2050, then it will have to tackle the emissions from the country’s 10,000 Grade 1 listed buildings. These buildings are notoriously difficult to refurbish because changes require listed building consent and because the interventions have to be removable to allow the building to be returned to its pre-intervention state. And often the refurbishment needs to understand the original design principles to ensure that the work enhances the building and does not cause longer term effects, for example by installing heating and changing the moisture balance in the fabric. 

Speaking at the last CIBSE Building Performance Conference, architect Oliver Smith, a director of 5th Studio, and Joel Gustafsson, senior engineer at Max Fordham explained how they tackled one of the most radical refurbishments ever attempted with the refurbishment of New Court, part of Trinity College, Cambridge. This scheme shows that with the right approach, a willing client and an imaginative partnership of engineer and architect a radical low energy refurbishment of a Grade 1 listed building is possible. 

The stone facade of New Court, Trinity College Cambridge
New Court is a neo-Gothic terrace of four-storey blocks that have accommodated students, including the current Prince of Wales, for almost 200 years. The conservation as normal approach would have been to do very little with this notoriously draughty building because its listing sets out to maintain the integrity of the building’s fabric. For New Court, the team set out to reduce heat losses by adding insulation and improving its airtightness

Adding insulation to the listed exterior was not an option so the team set about developing a means of insulating the walls internally. Aside from the need to obtain consent for the intervention, the team’s biggest concern with this approach was that improving the wall’s thermal insulation could lead to moisture and condensation problems causing mould growth and even result in some of the building’s timber joists rotting.

Sustainability fabric and systems:
a. Photovoltaic panels
 b. Fresh air intake and outlets
c. Extract air and heat exchange
d. Fabric upgrades – air tightness, insulation
 e. Underfloor heating
f. Ground-source heat boreholes
Using the hygrothermal modelling tool ‘WUFI’, Max Fordham evaluated a series of interventions with various insulation thickness and vapour barrier locations. With new build schemes, the vapour barrier is usually on the inner face of the wall, to prevent vapour entering the wall from inside. However, for New Court the modelling showed that solar driven moisture pressure would drive moisture into the wall from the outside, through the brick, stone and render walls where it would collect on the cold face of the insulation. To prevent this occurrence the team chose to leave out the vapour barrier to allow vapour to pass through the wall. The difficulty with this approach is that it restricted the amount of insulation that could be added because the wall had to remain warm enough to prevent interstitial condensation of the water vapour. 

The optimum thickness of insulation depends on the materials used to construct the wall so samples of the materials were sent to a laboratory for analysis with the results used to inform the WUFI model of the wall. 

At the same time as the samples were being analysed, the team also used monitoring experts ArchiMetrics to monitor the performance of the actual building. This involved measuring conditions internally and at various points within the wall. ArchiMetrics also installed a weather station to measure external conditions. The weather station enabled the WUFI model to be calibrated and its performance predictions to be checked against the walls’ actual performance figures.

Based on the model, the insulation solution selected was: 
4mm of lime plaster to level the wall’s inner face;
A 72mm thick sheet of wood fibre insulation;
An inner face of plasterboard.

In addition to insulating the walls the team also had to minimise heat losses and air leakage through the building’s wooden casement and sash windows. Over 30 options were modelled, including replacing the windows with double and triple glazed units. Although the windows are not original, English Heritage would not permit their replacement with new units so instead the old units were removed and refurbished. This involved replacing the existing glazing with slim, vacuum double glazed units and the addition of draught proofing.    

New bathrooms installed at New Court
An MVHR system prevents moisture build-up in the rooms. The MVHR units are hidden in the roof void; supply air is ducted from the units down the old chimney flues and into the rooms through the fireplaces. Air is extracted via the ensuite WC or allowed to spill into the communal areas via an undercut in the room door before it is extracted from the communal kitchen.

When the team applied for listed building consent with this solution, the local council used BRE to appraise the team’s work. The research organisation concluded that the exercise was robust, but decided that there was still a possibility moisture problems might occur. As a consequence, listed building consent was granted on the basis that the college undertake to monitor and report on moisture levels within the fabric for seven years. Should problems be discovered, then the insulation will be removed.

The refurbishment also involved the installation of new services, including new heating. A radiator heating system installed in the 1950s was removed and replaced by a low temperature underfloor heating system. Initially this is fed from an existing plantroom; in the future heat will be supplied from a ground source heat pump. A control system, incorporating an occupancy sensor, controls the heating and lowers the set temperature after four hours without an occupant; the set temperature is lowered further after the room has remained empty for 24 hours. Additionally, sensors located in the window frame turn down the heating when the windows are open.

Refurbished and upgraded windows are installed to maintain the aesthetics
The new lighting and room electrics are incorporated into a series of lining panels attached to the wall. Because these are interventions on a Grade 1 one listed building they are designed to be fully removable, the lining panels incorporate lighting and electrics and eliminate the need to chase wires into the wall.

Initial results show the building to be performing as expected, which should ensure the students are comfortable for another 200 years.  More importantly, the solution devised by 5th Studio and Max Fordham shows that it is possible to make radical energy improvements to the thousands of other Grade 1 listed buildings, and provides some practical examples of what can be done to inform those responsible for listed building consents.