I want to instead discuss an issue which I feel needs addressing. As a skeptic, I like to think that I consider all of the evidence and provide a balanced, factual and rational opinion. With this in mind I feel that the issue of the provision of on site renewable energy is one which needs addressing.

Soon after the release of the 2006 edition of Part L, Merton Council produced a planning condition which was adopted by many local authorities across the country. This condition was that developments must install a minimum of 10% on site renewable energy. Now on the face of it people may think this is a good thing, but is it really a good thing?

The European Parliament Building Directive, which is the legal drive behind the revision to the building regulations, requires that nations reduce the CO2 emissions from buildings. There are few people who could argue that this is a good thing. The overwhelming scientific evidence suggests that rising CO2 emissions are the major cause of global warming. There are of course people who call themselves global warming sceptics, though the correct name for these people is global warming deniers, in much the same way people deny the holocaust or AIDS. So it is accepted science that we need to reduce our CO2 emissions.

Part L 2006 was published with the aim of not only measuring the CO2 emissions from buildings, but also reducing them by a measured amount. For those who want to know my feelings on the 2006 Part L, you should read my post on this blog, entitled Pathetic Part L. Within the document, a reduction in CO2 was allowed for what was called LZC technology (Low and Zero Carbon). This was a fixed 10% reduction which was required to be met by the proposed building, in order to achieve building regulations approval. My own personnel feeling was that Merton council misunderstood this and called for this LZC allowance to be provided by the physical provision of on site LZC technology. So the Approved document allowed this 10% CO2 reduction to be met by the physical reduction of CO2, but ear marked it as a 10% reduction for the provision of LZC technology.

So what is wrong with this approach I hear you ask? Well in this instance, Part L took the more pragmatic approach. It actually allows us to reduce CO2 emissions, without providing any on site renewable energy. So how is this achieved, well simply by reducing the energy consumption of the building, which means the CO2 is not produced in the first place. The Merton rule however, requires us to install technology which is designated as an LZC technology, but which is still using energy. Let me illustrate this with an example.

Building A has a target CO2 emission rate to hit of lets say 50 kg CO2/m2/annum, for simplicity I will refer to this as 50 kg. The building is well designed, making use of good lighting control with high daylight factors, good insulation levels and correct orientation. Coupled with this, the installed services are highly efficient, low energy fans and air handling units with demand controlled ventilation and variable speed fans. The building has no installed renewable technology, but due to good design it has a Building Emission Rate of 40, a 20% reduction on the TER.

Building B is an identical building, so has the same TER of 50. Building B however is badly designed, with poor lighting controls, poor daylight provisions, standard insulation levels and wrongly orientated. The building services which are installed are merely just compliant with the minimum provisions of Part L and the ventilation system is not demand controlled, it runs at full volume for the whole of the occupied hours. However unlike Building A, Building B is provided with a Biomass boiler. The BER of Building A is slightly better than the target at 45, so it passes, though not as well as Building A. However because of the provision of the biomass boiler it has well in excess of 10% on site renewable energy.

So if the Merton rule was applied to these buildings, only building B would comply, yet building B has a greater CO2 emission rate and uses a great deal more energy. Biomass, though classifies as an LZC technology, still uses energy and in fact biomass boilers are generally less efficient than a traditional condensing gas fired boilers. So using the Merton rule, which people assume produces green and sustainable buildings, we have a building which not only emits more CO2, but uses more energy than a building which does not comply with the Merton rule!

The above example may be hypothetical, but it is quite realistic. The cost of LZC technologies is high and the benefits are generally minimal. Having said that Biomass produces very good results, but I will be posting about Biomass soon, where I will explain why I feel Biomass is a mistake. It can be cheaper to provide a good design, with efficient building form and fabric and efficient services, than it can to install on site renewable energy and achieve the same results. Building A in the above example has the added benefit of reducing energy consumption, which ultimately, whether you believe in global warming or not, no one can deny that our energy stocks are running out.

There are two main reasons why the Merton rule has gained such popularity. The first is simple, it looks good and provides a design which demonstrates tokenism. It can be claimed that the buildings are green and sustainable as they have biomass, ground source heat pumps or PV cells installed. The second is a point which I feel is true more and more. The whole of the design team feel that building energy consumption is very much the responsibility of the building services engineers. Architects and builders are not educated enough on how energy is used within a building to take any interest in the process. It is still very much regarded as a problem for the building services engineers to solve. If it is the problem of the building services engineer to solve, it is often best solved by adding renewable energy technology to the development.

So whats the problem with the addition of on site renewable energy? Well let me tell you. You have to remember that I strongly believe that CO2 emissions and energy consumption need to be reduced from buildings, I am not a climate change denier, I am a Skeptic. For any one who is unsure of the difference between a Skeptic and a Sceptic, then click on this link. I strongly believe in the use and installation of renewable energy sources, but I do not believe that this should be done on site, I believe it should be done off site. ON site renewables are generally a token gesture and not the correct solution for the building in which they are installed, or they are largely ineffective.

Consider the installation of a wind turbine on site. This is wholly the wrong place to install a wind turbine. The performance of a wind turbine is greatly reduced by nearby buildings and the terrain around for several miles. The manufacturers stated performance will never be achieved in an urban environment, so it becomes even less effective than it appears in feasibility studies, which is very poor to start with. The correct location for a wind turbine is in a rural environment or at sea.

Biomass boilers have been a very popular element over the past few years. The reason for this is that they produce great CO2 emissions at a very cost-effective rate. My feelings on Biomass as a sustainable option will be explored in a future post in detail. However, it is a fact that plenty of biomass boilers have been installed to meet renewable targets etc and once the first load of fuel has been used, the boilers never fire again!

Photovoltaics have become more popular over the past few years as prices have dropped and the new feed in tariffs which were launched this year make the use even more attractive. The problem I have with PV is that firstly, they are not very effective, they produce a limited amount of energy and secondly what is the embedded energy used in PV’s, well nobody seems to know!

I could go on, but I do not intend to appraise all LZC technologies. My feelings are simple, LZC and renewable technologies are best installed off site, where they can be installed in positions which best suits the technology. As fossil fuels are running out, how are we to best provide energy to buildings? Well to me the answer is simple, via electricity and the electrical supply must be decarbonized. All of the major developments in reducing building energy consumption have been made by the refrigeration manufacturers over the past few years. The efficiencies of these technologies is getting better and better.

So the 2010 Part L is soon to be published and the headline is that CO2 emissions will need to reduce by 25% from the existing targets. This will be a major challenge, one which building services engineers alone will not be able to achieve. It will be imperative that the rest of the design team are involved in reducing the energy demand of the building, before any LZC technology is provided. It has also been hinted that the European Parliament Building Directive will be revised this year and from what I hear the focus will be on energy reduction rather than CO2 reduction, this can only be a good thing. So my hope is that the Merton rule will be dropped by those authorities who employ is, as I hope I have demonstrated that it is a pointless rule.

The question of the blog title, what are builders really building is that they have no idea and they really don’t care! I have mentioned in a previous post about the issues of getting information from a builder on the constructions used in order to complete our Part L calculation. Well I finally got it and guess what the glazing did not comply with the minimum requirements of Part L! Yes that’s right, the builder had no idea that his building was non building regulations compliant.

I must stress at this point that this is not some back street builder, this is a national building contractor! But maybe it’s a little harsh to just blame the builder, let’s have a look at the trail of this in some detail.

First of all the architect has specified a glass with a mid pane ‘U’ value of 1.4. Well on the face of it, that appears great, as building regulations requires a maximum of 2.2, so it is much improved on that. The trouble is the 1.4 is a mid pane value, i.e. it does not include the frame and building regulations requires that the frame is included.

So I asked for the overall value to be confirmed. This on its own took a whole week for people to run around and find out this value. The builder asked the architect, the architect asked the window installer and the window installer asked the window manufacturer. The answer came back that the window had a whole unit value of 2.26. Now as I have already mentioned, it must be a maximum of 2.2 so this is a fail! Now the window manufacturer sent this calculation back to the window installer, who must have noticed that this was non compliant. So what did they do? Well they sent a rule of thumb table, which explained that the ‘U’ value would be about 2.1. Trouble is this was a rule of thumb table, which stated on it that this should only be used when there was no manufacturers data available. The stupidity of these people is unbelievable, they sent both these pieces of information together!!!!!

So they send this on to the builder, who just sends it on to me saying, here is the information you require, now I want my EPC! So what do I do? Well as I was doing an EPC calculation I put the 2.26 ‘U’ value into the calculation, but as it was a new build it should have passed the minimum requirements of Part L.

As a matter of fact the building actually flew through Part L and also gained a good EPC rating, but surely that’s not the point. As well as this incompetence on the contractor side, what about Building Control? Building control had apparently signed off the fabrics of the building! So what had they actually signed off? Not the calculation of the actual window ‘U’ value as it was higher than allowed and at the end of the job it took a week to produce!

What I am getting at here is that the whole chain involved are totally incompetent. What is an architect doing specifying only the mid pane values of the window? What is the builder doing not caring in the slightest what is installed? And what are building control doing signing off such things? At the end of the line the M&E engineers are left to produce the EPC and mop up the damage! All this when the fees of the M&E engineers are falling through the floor, as we are asked to do more and more.

By the way, if building control ask for an as installed Part L calculation (which they should, but rarely do), then this will flag up as a fail. But building control are just not interested in any of Part L, that has been proved to me time after time. So all that happens is that people continue to get away with building whatever they feel like and no one is there to tell them otherwise!

As a Building Services Engineer,  I have spent the last 4 years getting to grips with the 2006 version. My main area of interest is that of Part L2A, new commercial buildings and that is what this post is aimed at. For those who have been involved in this area, I am sure you have met the same issues as myself, for those who have not, then maybe you will find this post of interest.

The main aim of Part L is to reduce the CO2 emissions from buildings, an aim I have to say I whole heartedly agree with. My main issue is with the method employed to achieve this. The 2006 Part L was a major change to the building regulations and when I say major, it was almost off the planet.

In order to attempt to quantify the amount of CO2 a building was emitting, the government asked the BRE to produce a simple piece of software to perform these calculations. From this was born SBEM and the National Calculation Method (NCM). Though many pieces of software are available to produce the calculations (we use IES), they are all based on the NCM and SBEM (for those wondering SBEM stands for Simplified Building Energy Model).

The problems started when the BRE attempted to simplify the process. It must be stressed that the energy use of any building is far from simple, in fact nothing could be further from the truth. In order to explain where the problems are, I must now briefly explain the method employed.

A virtual model of the building is built, which has the same geometry as the building in question. To this model we assign a building type and to each room a room type (which are limited by SBEM). Each of these room types has a set of standard parameters, such as the amount of people within the space, the amount of ventilation provided, the amount of IT and other equipment, the hours of operation of each room etc etc. We are then responsible for assigning to each space a system to heat cool and ventilate, these are called systems. Each system is designated as having an NCM system type, which dictates if that system has cooling etc. We must tell the software the amount of electrical energy the system uses to run fans and pumps, what fuel has been used to heat, what fuel is used to cool, the seasonal efficiencies of the heating and cooling plant, the air leakage of the ductwork and air handling plant etc etc etc. Finally each room must be assigned a lighting load. A design illuminance is assigned, the actual energy the light fittings use and any lighting controls which are used, such as presence detection and daylight controls.

Above is a summary of the information which is required for just the building services elements, there are actually more intricate pieces of information which are to be added. As you can see there is a tremendous amount of information required and with any process which requires a large amount of data input, there is a great chance of error. Now there are several ways in which errors can arise. Firstly the information may be just input incorrectly, secondly the information asked for may not be known, so default values are left in which are wrong, the information may not be understood (you have to remember, no one had ever done a calculation like this ever before) and finally information may be put into the model which people know is wrong (and I shall come back to this last item later).

As someone who has performed many Part L calculations I can confirm that I am guilty of all of the above forms of errors at some time or other. Some large jobs, several hundred rooms, the process can take possibly a month of full-time work, what an amazing cost to add to projects, but it is the building services consultant in many instances who has had to shoulder the whole cost.

As I hope I have illustrated above, the building now consists of these NCM spaces, which have a set of parameters which cant be changed, occupancy levels, ventilation rate, patterns of use etc. So what we now have is an imaginary building, which does not represent the actual building we are building (though in SBEM speak, this is the real building not the actual building). So once we realise that we have an imaginary building, it is not difficult to realise that the energy use of the building is also going to be imaginary. Once we add in the different types of error that I have mentioned then we have a result which is wholly imaginary.

So we now have a result which is meant to predict the energy use, hence the CO2 emission from a building that we are building. But as we have now discovered, this energy use is totally imaginary and can not be trusted at all. On top of this, Part L does not include the electrical energy used by building for such things as computers, printers, photocopiers etc! The heat output from these pieces of equipment is added to the cooling load, but not added to the electrical consumption of the building.

As if this fantasy could not get any more weird, the SBEM now constructs what it calls a notional building. This is a building which has the same geometry as our building, but is built to the minimum requirements of Part L2 2002. Therefore it has less efficient systems, less efficient lighting and lots of glass.We now compare the CO2 emission of our building to the CO2 emission of the notional building and if our building emits approximately 25% less CO2 than the notional building, then we are deemed to have passed Part L.

So in summary, we create an imaginary building, and add an inordinate amount of complicated information, which will have plenty of errors and compare its performance to another imaginary building and if our imaginary building is better than the other imaginary building, then we pass Part L. Now bearing in mind that this is supposed to be a Simplified Building Energy Model! Could it really be any more complicated? I think not.

Lets now look for a minute at the process of proving compliance. Who is responsible for proving compliance? Well it is the building services engineer, the people who are designing the services, which along with the building fabric are being tested. Now its an important point to realise that builders and architects see Part L as a wholly services related problem, so they have no interest in the process and will build a building to minimum requirements, unless you can prove they need to do otherwise. So really, the services engineer is responsible for proving that his design passes Part L. Now I ask you, is he really likely to show that it does not pass Part L! Well not really. The government effectively made the Part L calculation self-regulatory. You must pass a training course in order to prove you could do the calculations (and let me tell you I have done the course and it in no way taught you how to do the calculations, I was left with many more questions than answers). So as long as I can write a report and show an output from the software that says the building passes Part L, then building control are satisfied.

Now I consider myself and the practice I work for to be honest and diligent and committed to the challenge of energy efficiency which the whole world is faced with. I am in full agreement with the spirit of Part L and the EPBD, but I like all other consultants would never get to the end of a job and prove that the building did not pass Part L. If I did the builder would make sure that my practice paid to make sure that the building did pass. Now this may involve in installing a wind turbine, a biomass boiler or some other costly measure. We may be talking £250K or even in excess of that. So what am I more likely to do, tweak a figure in the calculation that no one will ever know I have tweaked, or admit that a great deal of money is required to ensure Part L compliance?

Now I don’t want to create the impression that this is what myself and my practice do on a regular basis, but I have to admit, that if we were in this situation I know what we would do and I know that other consultants would do the same. And when you bear in mind that these calculations are based on imaginary buildings, then there is some justification for doing so.

I am certainly not advocating that this should be done. In fact I have developed a method at my practice to ensure that a Part L calculation is performed early in the project and is performed accurately and provides feedback to the design team as to the measures required for the building fabric and geometry. I can however admit that in the first 18 months or so of the industry getting to grips with the new Part L, many calculations were performed, which would now not bear ant scrutiny at all. This is not necessarily the case because we tweaked figures, but because we were not sufficiently aware of the calculation method.

With all this in mind, we can say with a great deal of confidence that the results gained from Part L calculations and EPCs (as it is literally a different button to press on the same calculation) over the past few years, bear absolutely no resemblance to the real energy consumption of the building. It is not surprising that people are asking why the DEC is so radically different from an EPC. Well the reason is that the EPC is based on an imaginary building, with incorrect information added, while the DEC is a real measure of energy use.

As I said when I started this post, I am excited at the new revision to Part L which is due out any day. I have studied in great detail the draft documents and the method of calculation has not changed much, so it appears that the same problems will persist. Oh well!

So what is involved in producing an EPC and what are the problems with them. Well firstly we must know what the details of the building fabrics, including ‘U’ values and the individual elements used, i.e. what is the wall made of, what is the roof made of etc. Secondly we must know the geometry of the building, how all the rooms link together, how much glazing there is and is there any solar shading etc. Finally, we must know the performance of the building services systems.

Lets look at these elements in reverse order. We can confirm the performance of the services by asking the M&E contractor the relevant questions. What is the seasonal efficiency of the boiler installed, what is the seasonal efficiency of the chiller, what is the energy consumed by the lighting in each room, what lighting controls are used, what is the specific fan power of the air handling units and the fans etc etc. In my experience the M&E contractor confirms this information pretty easily, though it can take some time.

The building geometry can be confirmed by architects drawings, GA’s, sections and elevations etc.

So we now have to confirm the actual details of the building fabrics used. In order to find this information all we have to do is ask the builder what he built his building out of, right? Well you would think so, but let me tell you, this can often prove to be the most difficult information to receive!

I have developed a standard request for information sheet when we are producing an EPC. We issue this as soon as it is confirmed we are producing the EPC. All the information I have mentioned above is on this list and you would think that as the building has just been built all this information should be readily available, but it is not the case.

On a recent project, we issued this request for information sheet to the main contractor once he had appointed us to produce the EPC. Two weeks later we had all building geometry information and all information relating to the performance of the building services, however we had no information regarding the building fabric. I emailed the main contractor and asked him when we could expect this information, he told me we had the architects performance specifications and as such we had the relevant information! I was astonished by this answer. I attempted to contact him by telephone to discuss the matter and was met with no answer. After leaving messages on his voicemail I received an email telling me to stop procrastinating and provide him with his EPC.

Eventually I managed to speak with him and explained that I was not procrastinating, but that I was attempting to do my job in a diligent manner. The information I required was the actual installation details of the constructions. Basically I was asking the builder to confirm to me what he was building his building out of. He could not provide me with this information!

The more we talked, the clearer the problem became. He had worked on a project previously where the EPC had been produced where this information had not been asked for! Software that is used to produce an EPC (we use IES) has default constructions which are used for the building if no others are assigned. For instance, in IES the default construction for a roof is concrete, internal partitions are brick etc etc.

It is obvious that many EPCs have been produced which use many of these default constructions, which may well have the insulation levels tweaked to produce the correct ‘U’ values. Personally I am horrified by this. The materials used can have a significant impact on the energy performance of the building, yet builders seem un concerned about this. In this particular project, the builder told me that as he had not been asked for this information on previous EPCs he was not going to provide it to me on this project. I informed him that without this information I would not provide him with his EPC.

Eventually after having to speak to his boss, I was provided with the information I required, though not from the builder, but from the architect. This attitude is typical throughout the construction industry that anything to do with energy performance of the building is purely the domain of the building services engineer.

There is so little knowledge and understanding of a building’s energy performance within the majority of the construction industry. Having said that, there are major pitfalls in the legislation and enforcement. EPCs are generally produced by a consultant for a fee, a fee which will generally barely cover the cost of producing it correctly. Given that EPCs are self-regulated, i.e. the person producing it is responsible for ensuring it is accurate, many seem to be taking the view, why waste time gathering lots of information, when we can use default figures etc. Who is going to interrogate the EPC? Does anyone within the construction industry have the knowledge to interrogate an EPC? The answer is a big fat no!

What we are left with, is lots and lots of EPCs which are being produced which are wholly inaccurate and meaningless. There are no independent checks been undertaken that the information input into the calculation is accurate! There is no one who seems to care much either about the EPC been produced accurately. All this makes me think am I wasting my companies money? I could have produced an EPC for this project several weeks ago. I could have used the default information within the software for the different types of constructions and had the EPC issued weeks ago and saved everyone money.

The reason I have not done this is that I believe that the process should be undertaken properly, I also believe that the rest of the industry should be informed as to how the process works. It seems there are few of us out there who actually care about the accuracy of the results. I can only hope that the government begin to address the checking and enforcement process of EPC production, or the whole process will become a waste of time and the industry will be a laughing-stock.