CIBSE Guide F: Energy Efficiency in Buildings 2012

Since the last edition of CIBSE Guide F, published in 2004, the UK Government has set a legally binding target to reduce national greenhouse gas emissions. The Government’s latest Carbon Plan sets out specific targets for improving the energy efficiency in new and existing buildings. There have also been significant regulatory changes over the last decade, including two revisions to Part L of the Building Regulations and the transposition of the Energy Performance of Buildings Directive into UK legislation. The next two revisions of Part L will push for further improvements in energy efficiency to progress towards the Government’s aspiration for all new buildings to be zero carbon by 2019.

This 2012 edition of CIBSE Guide F includes a new section on ‘developing an energy strategy’. This reflects the changes to planning policy, which now include targets for reducing carbon dioxide emissions from new developments and the need to submit a detailed energy strategy report as part of the planning application.

Energy management has moved up the corporate agenda, aided by the work of the Carbon Trust and the implementation of the CRC Energy Efficiency Scheme. Part B of this Guide (covering the operation of the building) has been updated to include more information about carbon management, and the need for improved metering and monitoring.

In addition, the section on energy efficient refurbishment has been expanded in recognition of the pressing need to upgrade the existing building stock and the opportunities to improve performance.

Contents include:
Part A Designing the building energy design checklist: The design process; Developing a design strategy; Developing an energy strategy; Concept design; Control strategies; Ventilation and air conditioning design; Refrigeration design; Lighting design; Heating and hot water design; Motors and building transportation systems; Electrical power systems and office equipment; Checking the design; Commissioning, handover and feedback
Part B: Operating and upgrading the building — Why buildings fail on energy: Managing the building; Acquisition and refurbishment; Maintenance and energy efficiency; Energy audits and surveys; Benchmarking, monitoring and targeting (M&T), and
Part C: Benchmarks: Energy benchmarks.

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Tuesday, 10th December 2013

Feifei Sun, NPS Group

Hull City Council has a target of 34-45% by 2020 compared with 2005 baseline and we are keeping the full data set from 2000. In the last decade, the energy consumption has yo-yoed (unfortunately last year was 7% increase based on 2005 level) however the energy cost has nearly DOUBLED from 2005 to 2012! Even with a stable energy reduction year by year, we still can’t beat the price rise on utility!

When we compare schools with the benchmarks for gas usage, most fall in between typical and good practice, benefiting from constant boiler updates, insulation etc. Most electricity figures are much higher than typical.

NPS has started to develop a benchmark for Hull. We started with the weather data first, rather than the degree days, because the theory of ‘degree days’ was originally invented for measuring ‘crop growth’ and ‘pest controls’ and it depends on the base temperature, which again different building types will have different base temperatures. Another point is that Leeds weather data is the recommended representative for our region, but Leeds is more up on the hill and Hull is more open to the sea with strong wind. We used the average temperature of 3 weather stations around Hull. Therefore, we created a 12 yr pattern of weather and energy consumption, which allowed us to filter out those who had followed the weather pattern, and those who hadn't – just another fresh idea for approaching the benchmark data.

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Friday, 6th December 2013

Phil Jones, Building Energy Solutions

Until Guide F 1998 there was no single publication covering energy efficient design and operation. I pulled all the known benchmarks together for the 2004 ed which provided a central resource in one place. It gives guidance but then directs people out to other CIBSE Guides and wider resources for detail.

Guide F encourages designers/FMs to go beyond minimum standards which are too often seen as the target when they are the MINIMUM.

Benchmarking has been neglected over the last 10-15 years since the EEBPp and now requires funding. I have personally collected data and benchmarking but it requires further work. If anyone has data then please get in touch, see my call for data on the CIBSE Energy Performance Group on LinkedIn [Shameless plug - EPG are also on Twitter @CIBSEepg and www.cibse.org/epg]

Benchmarks in Guide F are for EXISTING buildings. I'm not aware of any publicly available benchmarks for new-build. Large practices have their own but commercial confidentiality prevents adding them to Guide F. CarbonBuzz is progressing but needs to be much more heavily populated before we can get robust new build benchmarks.

TM46 provides statutory benchmarks that underpin DECs based on boiled-down Guide F figures. We did an analysis of the DEC database 2 years ago - the TM46 benchmarks in some sectors were pretty good but there were sectors that were significantly out. See http://www.cibse.org/index.cfm?go=news.view&item=153

TM54 is an excellent publication and a major step forward in spanning the performance gap. It brings consistency to the estimation methodology and has lots of helpful numbers on inputs to the method, giving support to designers. We need to encourage designers to use the methodology but even more importantly ways to get clients to ask their designers to produce estimates based on TM54.

I have suggested a wiki idea to keep publications up to date allowing future Guide F authors to access a set of comments/updates from a wide range of engineers. CIBSE's Knowledge Portal will be able to do this and electronic addendum/supplements published showing refereed updates to guides at more regular intervals.

Energy Performance Contracts, BIM, Dynamic Modelling etc could feature in the next edition.

Metering problems - sub-metering was introduced into Part L 2002 / TM39 but practical outcomes have been disappointing. The metering and AMR sector is not doing what it says on the tin – see my paper to CIBSE Technical Symposium 2012 about my concerns http://www.cibse.org/index.cfm?go=page.view&item=2374

A CIBSE/RIBA/RICS publication on energy efficiency would need to be at quite a high level and then reference Guide F. Essential that we avoid silos and get more cross collaboration and integration.

Log books haven’t been enforced properly over 10 years resulting in poor uptake. Part L has suffered from 'good regulation but poor policing'.

DECs are the critical tool we should be focussing on as these are REAL building miles per gallon and REAL carbon emissions. The industry should insist on mandatory DECs on all buildings plus making gradual improvements in the DEC process and benchmarks.

A lot of the comments support my current view which is that this is not really a technical problem anymore – to paraphrase Bill Clinton “It's the people stupid!” We really need to focus on real operational performance and that is often down to poor management and occupant behaviour (although some poor design, installation, commissioning as well). Guide F covers human aspects a bit but we need to make much more progress in this area. We need to change attitudes/practices in clients, designers, installers, commissioning engineers, FMs, maintenance engineers and energy managers. I see this like a chain – it only takes one of the links to break and you end up with a bad building. With these odds it’s not surprising most of our buildings are poor performers!

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Friday, 6th December 2013

Colin Lillicrap, Colin Lillicrap Associates

There are a number of challenges

1. There is widespread misunderstanding of the gap between design and operational energy predictions. There can be many reasons for this gap but the way it is often presented casts doubt on the design process and the software tools used to predict energy use.

2. Many people are trained as energy assessors using SBEM to produce EPCs/BRUKL reports for low fees. Time constraints and commercial pressures mean they rarely explain that the calculated energy use is a poor indicator of the operational energy use.

3. Architects create the design concept with the client and then pass to the M&E consultants to make it work. Quantitative analysis of how the concept will perform in terms of energy use or comfort levels is uncommon. Additionally, many architects regard computer modelling as a constraint on their artistic flair.

Engineers and modelling specialists need to be more effective at selling their services to financial institutions. Experts in in-depth modelling can make reliable predictions on performance and energy use between design options. We should sell the benefit of potentially lower capital and running costs as well as achieving client's objectives. We need guidance that investors, developers and main contractors will understand and be motivated to read in order to educate them about how to acheive good building design and hence value for money.

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Friday, 6th December 2013

Peter Lynes, Leeds City Council

In my experience, the actual emissions outcome is as much dependent on the people operating the system after hand-over, as it is on the design of the systems. I made a presentation based on two of our schools, one of which was a modern well-insulated build with modern systems and one all-singing, all-dancing BMS. The other is a draughty school that has grown “organically” since the 1950s, and has about 17 different control systems, ranging from a finger on a switch, to a cheap BMS. The older site regularly outperformed the newer, because the school's bursar employed an team of enthusiastic “psychopaths” as superintendent and caretaking staff, who made it their life's mission to reduce energy use. The modern school team assumed that their BMS was already doing everything that could be done, so did nothing!

O&M manuals and handbooks are critical. I’ve attended handover briefings where a controls engineer has been delegated to instruct a caretaker as to how to "Do this if that happens", with no attempt to explain that systems should be continuously managed, monitored and optimised.

Ideally, the Building Log Book operational instructions should be prepared when the initial building spec is drawn up. Designers should describe how they expect the building to reach and stay at peak performance. Consideration of this point early in the project might well result in buildings that perform consistently well over their life. You must design products that are capable of “doing what they say on the box”. Why should that not apply to buildings?

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Friday, 6th December 2013

David Cheshire, Aecom

As opposed to just a collaborative guide, CIBSE's energy efficiency guidance could be more integrated into other CIBSE guides.

We do need better benchmarks but there is masses of data out there, we are just not sharing them enough. Operational energy performance data is useful at the design stage to inform our design stage estimates. TM54: Evaluating energy use at the design stage is intended to form the 'missing link' between design stage estimates, which are rarely done at the moment, and operational performance.

We often use compliance calculations for Part L as estimates of operational performance, which is a mistake, resulting in a huge gap between design and performance. Better estimates of operational performance mean that we can get designers and prospective operators/occupiers to focus on the key issues that make the building design more energy efficient (e.g. good controls, metering, commissioning and handover!), and we can use the design-stage breakdowns of energy use to compare and diagnose issues when the building is in operation.

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Friday, 6th December 2013

Matthew Wall, Sainsbury's

Updated benchmarks would be a good thing. However, I am unsure as to how appropriate, practical and cost effective this would be for a national estate. The existing benchmarks were intended to inform Energy Management and efficiency of existing buildings for purposes of comparison – not design of new ones. Updated benchmarks may well be out of date by the time of publishing because they reflect the performance of existing buildings whereas mandatory design standards and best practice have moved on.

Could a short term alternative be publishing approved (annual?) factors to adjust benchmarks to suit the attributes of a particular project, e.g. for age, occupancy etc. This in itself is a significant project, and we may well still require updated baselines, but this may be enough.

There will be implications for procurement routes and the growth in Contractor lead projects. Energy performance can as much be a contractual issue as a technical one for the Client’s team, especially given the cost competitiveness on tendering. As designers we tend to focus on form, function, materials, etc and ignore the commercial focus that comes with a Contractor's D&B project won on the basis of low capital cost. Guide F needs to advise on the need for effective communication with and review of the output from the Contractor’s team and the role of Employer’s Requirements, the Project QS and the value engineering process.

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Friday, 6th December 2013

Lindsey Malcolm, Buro Happold

National calculation methodology is the methodology used within the Part L2A (new non-domestic buildings) performance assessment to define the notional building (which sets the target kgCO2/m2 for the building) and the comparison with the actual building design. There is a little on Pinpoint here:

http://pinpoint.ukgbc.org/resource/7413

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Friday, 6th December 2013

Lindsey Malcolm, Buro Happold

More engineering professionals should be made aware of Guide F and be able to use it robustly e.g. take on-board the recommendations but don’t use benchmarks where they aren't appropriate.

I do feel there is an opportunity for modelling and analysis at the early stages of design and we should be encouraging design teams away from the concept of Part L as a measure of energy efficiency. Aside from the fact that NCM isn't representative of building operation; that some approaches comparing to a notional target don’t necessarily lead to the most energy & carbon efficient design solutions; it means that by waiting until a building has form, function and a systems strategy we are starting too late in the design process. Greater consideration should be given to the potential of parametric and optimisation analyses when looking at concept design in order to deliver the best solution for the particular building in question.

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Friday, 6th December 2013

Matt Cotton, National Energy Foundation

Benchmarking is hot on the agenda for a number of bodies including NEF, CIBSE, UCL (who are exploring the development of tailored benchmarks) and Better Buildings Partnership (developing Landlord’s Energy Rating). We shouldn't however lose sight that the main section of the Guide provides excellent content on the basic approaches to good, energy efficient design and operation.

BS engineers must engage the design team and the client and ensure fundamental principles of low energy design are integrated at concept stage and at 'as built' stage before turning to whole building models, software (BIM), Part L/BRUCKL calcs to get an answer. Guide F sets out these basics very nicely.

Whilst engaging other professional bodies would make sense (Guide F doesn't come up if you search for it in the RIBA book shop), most engineers aren't aware of Guide F unless they have been through CIBSE's Low Carbon Consultants course or similar. Exploring ways to ensure that the principles of good low energy design, with reference to Guide F, are instilled in all engineers and architects through university courses, internal CPD programmes etc would go some way in overcoming this.

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Friday, 6th December 2013

Nick Macdonald-Smith, DTZ

Re: Benchmarking. In general, we are involved with asset improvement & refurbishment of existing buildings, usually multi-tenanted and owned by larger investors, to make them more energy efficient. Benchmarks work as good guides when no work has been undertaken. However, energy use in multi-tenanted buildings is more complex than a set of benchmarks developed for ‘whole’ buildings, where gas use is split across all occupants/common areas and electricity use can be individual to each demise. There is still a large proportion of ‘unknown’ energy in property due to the separation of tenants and landlord data despite an increase in data sharing between tenants and landlords due to ‘Green Leases’ etc. Landlords need useful and easily communicated metrics to be able to make a financial decision in energy improvements.

FMs are 'on the ground' and understand the quirks of the building they operate so they should be involved as early on as possible. Log Books for existing buildings are key to ensuring the building is operated correctly. All too many buildings are operated with no O&M manuals on the equipment design and operation, much of which has been installed decades ago!

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Friday, 6th December 2013

Bill Wright, Electrical Contractor's Association

Users of the building should be involved even at the design stage. The end user is the most important part of the chain as users can override any automation within a building. They need to know how the building is designed to be able to run it efficiently.

Guide F is good but some areas of benchmarking, regulations and compliance are outdated. Benchmarks are also available in TM46 but some of these are already out of date as well! Annual electronic updates, printable for those with hard copies, and sold on a CIBSE subscription basis would be useful. Additionally, the RIBA stages have changed recently.

Working with other bodies such as BIFM, RIBA, UKGBC would be very helpful.

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Friday, 6th December 2013

Joe Treanor, CarbonPlan

Guides & standards should be implemented at the concept stage. Engineers currently must provide a product with what the designers have left room for which is a difficult task. Additionally, many specifications are value engineered out due to cost resulting in not knowing whether they have been installed or not. All of this starts the decline of energy efficiency.

Energy targets are set at planning stage based on design information however, energy assessors are not involved until after design/planning stages. Situation where things are designed twice, before and after planning, should be avoided as they inflate costs and are highly inefficient.

A guide is needed with annual peer reviews and current data/trends/techniques to maintain a position at the forefront of building knowledge with hard data, collected in a universal manner (probably at the European level) to support it. A collaborative approach to underpin the ‘guide’ may benefit from a working group like CPIC formed of members across professional institutes to bring together ideas and knowledge. For energy efficiency, an assumption to avoid in this situation is “the other guy is taking care of it”. We need a robust model of verification to counteract this notion.

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Friday, 6th December 2013

Lindsey Malcolm, Buro Happold

As a point of comparison the benchmarks are still a useful starting point when faced with a complete lack of data and do align relatively well with a lot of the existing building stock we see that is being considered for significant refurbishment works.

Architects do not need to be technical energy experts, and engagement can be limited to a working understanding of the energy modelling process (see An Architect’s Guide to Integrating Energy Modeling in the Design Process). This would give architects, developers and financial institutions an understanding of the potential of analysis for energy efficient design.

Multi stakeholder guides should also include BIFM - why design an energy efficient building if it is not run in that way? But also educate at the design/engineering stage of operational foibles that prevent good performing buildings.

I've seen successful stakeholder engagement with owners and occupiers taking place at early stage design and based around user experience (sight, sound, feel, comfort, natural daylighting, wellbeing, etc). This helps with a holistic approach to sustainable and energy efficient design. This isn't a common approach and commercially driven development needs to consider the longer term for this to adopted.

What does industry think of a cross-institution amalgamation of operational data, benchmarks and performance metrics into a single online repository? It could integrate with EPC/DEC registries (to bring in data on newer buildings) and/or CarbonBuzz in order to highlight the performance gap between design and operation as well as providing a single point source of benchmark reference data. Commissioning, handover support, audits, surveys, feedback, post-occupancy evaluation are all critical components that too often fall by the wayside in light of ensuring a building can open on time and the developer can get a return on their investment.

Repetitive changes & overhauls of regulation should stop and Gov should set aside a fund and a specialist body to facilitate comprehensive handover and operational review of all new buildings to ensure they are delivering on their design promises and those operating them fully understand how best to do so.

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Friday, 6th December 2013

Colin Lillicrap, Colin Lillicrap Associates

A RIBA/CIBSE/RICS guide misses out the important finance aspect. Engineers are not present at the concept stage where influencing the design and performance would have the greatest effect. A guide targeting those who initiate projects (developers, main contractors, specifiers and in some cases architects) with a clear financial message giving the benefits of bringing together the complete design team inc engineers & energy consultants, at the concept stage. Additionally, we have excellent software tools for quantitative design studies to identify an optimal solution to meet specifications however, often no one wants to pay for the studies. Linking with a financial institution may give some insight in how to do this.

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Friday, 6th December 2013

Peter Lynes, Leeds City Council

The current situation where clients are almost instructing us to nail down a design at a given date, to comply with an outdated set of regulations, is backward looking. Relying on historical standards ensures that every new building becomes “part of the problem”, rather than “part of the answer”.

We must design for the future. Leeds CC has a clear aim to reduce its own carbon emissions, and the City's, by 40% by 2020 (compared to 2009). This can only be achieved by the use of forward-looking standards that acknowledge and incorporate such reductions. A table, perhaps reviewed annually, indicating the kinds of standards that should prevail, at a given future date, would be helpful, so that designers specifiers, and constructors have plenty of notice of the standards.

Collaboration across the professions could break down professional silos and produce more efficient buildings. Building design is often determined by "fashion" and passed to BS engineers/systems professionals to make the building run for the least cost rather than placing user comfort, followed by emission reductions, for least cost as the central principle. Putting all participants in a room could achieve this aim. Guide F should become a joint RIBA/CIBSE/RICS publication to promote the joint nature of the task.

We are trying to produce holistic, sustainable buildings that hold their own against future emissions standards. A CIBSE/RIBA/RICS Guide F, 2014-2050, updated electronically, each year could get everyone singing from the same songsheet! As far as I’m aware, the last verse on that particular songsheet is “80% reduction by 2050”. That can ONLY be achieved by the implementation of a shared set of values.

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Friday, 6th December 2013

Joe Treanor, CarbonPlan

Agree on the data issue - the future of energy efficiency will be held within ‘live data’ eg BIM.

Energy efficiency should be incorporated within projects and studied alongside other factors, not as another bolt on, or an additional potential objective in the overall scheme. Adopting an energy strategy will cement this approach.

Consideration of the design and end use efficiency targets should be held in the forefront of any changes made during the entire process. The integration of energy efficiency throughout the BIM chain will help instill the ideas and ethics. Improved metering and monitoring will allow users to see how they are faring, improve and adapt. This could be seen as a guide? This will also hopefully help with building handover, and so the users are aware of the designers ideas and energy efficiency targets.

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Friday, 6th December 2013

Nick Macdonald-Smith, DTZ

I agree on the age of the data - although this has been updated through TM46. An online, regularly updated version of the Guide might be a useful method of keeping it up to date, possibly on a Wikipedia style of editing to ensure updates are factual and accurate, or regular calls for technologies to be included and/or dropped.

Clients are becoming more aware of making refurbishments durable through drivers like the Energy Act and the Energy Efficiency Directive. Paying for improvements is still tricky as the finance implications of the Green Deal are not favourable and leases in use do not allow for flexibility in how improvements are accounted for during or at the end of the lease. I see that clear options for financial analysis and models for refurbishment investment would be useful additions to the Guide, on top of the small section on Net present Value and Life Cycle Analysis etc. This may even stimulate the Government to look at properly at regulation in the Energy Performance Contracting arena.

In addition the use of BIM and dynamic simulation are already and are going to be very useful tools in the future for energy efficiency options and impacts on design – possibly the future of Guide F?

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Friday, 6th December 2013

Colin Lillicrap, Colin Lillicrap Associates

Guide F is a useful reference source but much of the data, especially the benchmarks, are based on data collected for the Energy Efficiency Best Practice Programme, some going back to the 1980s. Technology has also moved on significantly.

Clients in energy efficiency projects only ever want the legally required minimum. Guide F only indirectly impacts on the success of measures. Its main use is in providing a source of default values when we do not have data.

For energy efficiency to become the norm design team will need to be forced to consider design optimisation at a much earlier stage. Currently, this happens at when the project passes to M&E consultants for an energy performance assessment to comply with Part L. Guide F is of little help in this context as we have to use a prescribed National Calculation Method. TM54 is a more useful document but I would have like to have seen a clearer distinction between optimising the building elements and fixed services as an integrated whole and the rather different requirement to provide the developer with an estimate of operational energy use.

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Thursday, 10th October 2013

Janet Beckett, Carbon Saver UK

CIBSE Guides and Technical publications are the industry "bibles" for not just CIBSE Design Engineers but for anyone who is technically competent and absolutely serious about implementing energy efficiencies demonstrated through sound first principles of engineering.

The new section on energy efficient refurbishment would definitely be my choice when advising clients on existing commercial buildings.

Why on earth DECC did not use the CIBSE resources when implementing the ill fated green deal is a mystery.

Janet T Beckett

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Friday, 4th October 2013

Colin Lillicrap, Colin Lillicrap Associates

As the Steering Group Chairman for the original Guide F I am pleased to see that it now in its third edition. It provides a useful reference document for anyone involved with energy use in buildings. The new section 4 'Developing an Energy Strategy' is particularly welcome as it covers changes in legislation since the original guide was published and the move towards low and zero carbon buildings.

Colin Lillicrap

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Thursday, 3rd October 2013

David Fisk, Imperial College London

We use this on my Masters Course (its free to CIBSE students) as a hype free text suitable for real engineering work. It's especially useful on different ways of organising design and construction away from the traditional Plan of Work to improve effectiveness in energy performance. Its also neatly modularised.

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