Implementing Zero Carbon in London

Now that we are almost upon the deadline for the introduction of zero-carbon (GLA) in London I thought that it was timely to comment on it. 

Firstly. Brilliant! In a time when politicians appear to have taken leave of their senses permanently, it is reassuring that here (surrounded by the metropolitan elite) some things stay the same. We have a group of politicians willing to lead on principles rather than on the basis of prompting by tabloids or by their lesser selves. Well done London!

Secondly: Brilliant! We have a piece of zero-carbon legislation that has learned from the recent past, from multiple consultations by DCLG and the Zero Carbon Hub and run with it rather than reinventing this particular wheel. More importantly, it sets a precedent for other devolved authorities to follow. London can afford to lead on this one, to get the idea moving, to introduce developers and their design teams to the idea and to pioneer mechanisms for using the funds in a transparent and timely way so that developers can see the benefits to them. 

Thirdly: There is work still to do, as there is little clear understanding about many of the aspects of the new legislation. Can we claim a credit for making improvements above regulation? For example if the team introduce dimming into the building, can they claim some CO2 reductions below the line of the regulatory calculations. If the designers use a timber structure, can they claim some embodied energy reductions? When are the payments to be made? When the building is designed, or when it is built? There are likely to be differences between the two.

I think that it would be useful if the GLA held some workshops about this new legislation and had an open discussion about these questions, to help to introduce the legislation and to hear from design teams and clients how it can work best for them and for the GLA. It is very important that this new effort succeeds, it is practically the only star left in the low-carbon buildings firmament, so let’s make sure that it burns brightly and it isn’t extinguished at the first sign of difficulty.

Is London going to go Zero Carbon?

Business Green reported an interchange last week between the Mayor and Green Assembly Member Darren Johnson  in response to his question about the Mayors position on Zero Carbon homes. Boris’s reported response was

“What we are looking at is making sure that we can continue, through the London Plan, to ensure that Zero Carbon Homes are delivered in London and we will be issuing further guidance in due course to provide industry with the certainty it needs about how to do that.” 

Boris reported that London aims to achieve a 60% reduction in CO2 by 2025 and has achieved 14% to date. This represents a per capita reduction of 20% as London’s population has grown by 600k during the reporting period.

It is heartening to hear these words from the Mayor, and I hope that the candidates for the Mayoralty are listening. If devolution is to mean anything it should promote the ability of cities in the UK to sidestep the damaging and short-sighted environmental policies of central government.

Having recently completed a large zero carbon scheme at Hanham Hall with low-rise construction and learned what it means for most of the UK’s housing development, I thought that it would be useful to share below some analysis that we have done to assess how tall buildings can achieve the zero carbon standard. Given that many of the buildings that are proposed for the capital in future are going to be tall it is interesting to assess how the regulations might affect those building types.

The analysis has been done for a twenty five and a forty storey tower with six units per floor to demonstrate how different systems meet the targets. We tested gas boilers, CHP with gas backup, all-electric heating and hot water and finally Air Source Heat Pumps. Three of the four rely on a communal hot water distribution system, the all electric system being the exception.

Energy Options to meet the London Plan and Zero Carbon

Energy Options for a 25 Storey Tower to meet the London Plan and Zero Carbon



Energy Options fora 40 Storey Tower to meet the London Plan and Zero Carbon

What the research shows is that for taller towers there is no difficulty in meeting the current definition of zero carbon. In fact it shows that achieving it is technically easier than achieving the London Plan, as the London Plan has a lower emissions target than the Zero Carbon definition. This is assuming that there is no special treatment for electric heating or hot water, unlike the current version of SAP which is based on comparative performance rather than on a definite figure as set out in the Zero Carbon Hub’s definition.

Based on these figures I would say that towers should be forced to meet the lower emissions target of 10kg/CO2/sqm since in both gas-based options this target can be met. Perhaps an all-electric version could be left as it is at the higher 14kg/CO2/sqm.

It also shows that a very efficient 25-storey building can meet the targets irrespective of the energy system used, the top graphs shows that it can achieve the target in all four options, even an all-electric option. The 40-storey is not so easy. My assumption is that only the roof can be used to house renewable energy,  but for the 40-storey version it would be necessary in the electric options to put some pv panels on the facade to reach the target.

But of course the technical success is not the full picture. In addition to the Fabric Energy Efficiency target of 39kwh/sqm/yr that apartments have to hit, and towers have no difficulty doing so, there is the Carbon Compliance which is shown in the graphs above, and again there doesn’t appear to be much of a problem for towers, but finally there is the Allowable Solutions element which says that whatever CO2 emissions remain must be offset. This offset is achieved by multiplying the tonnes of CO2 emitted, by the figure of 30 years, and by an agreed sum for each tonne. Currently the GLA uses £60/tonne. This produces a figure of approximately £1,000 per apartment to offset the emissions elsewhere.

Sadly the all electric system is unwelcome in London as it it not seen as ‘futureproof’ according to the gas-led ideology preferred by the GLA. This is understandable as an all-electric system does not emit the lowest CO2 emissions possible, at current levels of grid CO2 intensity. What will be interesting to see is how long before the grid CO2 intensity drops to a low enough level to change that thinking. The Committee for Climate Change has suggested that we need to stop burning gas by 2035 to meet our carbon budgets. What is the point in investing in gas burning equipment and networks now if they have to be decommissioned in less than twenty years time?

Certainly an all-electric system is the cheapest to install, avoiding the central distribution system, and it could be argued that an all electric system is just as futureproof as a hot water led system as the Grid is inherently flexible. Interestingly our research also suggests that in the majority of cases an all-electric system is cheaper than a communal system for residents as the standing charges are lower, even if the energy bills are higher than gas. The standing charge is used to create a sinking fund to replace the communal system. If there is no communal system the sinking fund is either not needed or is much smaller, thus lowering residents total bill. The cheapest system of all to run is an individual gas boiler, but no-one would consider installing that into a tower, and it has a higher maintenance and replacement cost than an all-electric system.

A major hole in this analysis is that it is carried out using SAP, which is pretty poor at dealing with apartment buildings. The energy for pumping heat around the building is ignored, as is the energy for ventilating corridors, pumping hot water, lifts, communal lighting etc, etc. Since the communal spaces in these buildings are not heated, SBEM isn’t particularly useful either. As buildings get taller these additional energy uses and losses will become more a more significant part of their energy use, we need better tools to assess them, and more regulations to deal with their particular demands.


VELUX Daylight Symposium 2015

The Location: The event was held at the Tobacco Dock, a reminder that some reused buildings provide stunning locations for events, and in this particular case the event was held in daylight. It may sound obvious, but most conferences are still held in locations where daylight is excluded, in case it interferes with the presentations. The usual result is a lot of sleepy attendees watching a lot of fairly tedious slides. When light levels are lowered, our bodies natural inclination is to go to sleep, a fact that the designers of most auditoria seem to have ignored. 
The lantern lights of this tremendous building were modified by simple banner-like screens to prevent glare and the two days were spent with the delegates bathed in full daylight but still able to view the screens. I cannot emphasise enough how much nicer an experience it is to spend a day in this way, rather than buried in the bowels of some convention centre.


The Content: The Daylight Symposium is a unique event, bringing together the worlds leading experts in daylight research and practice. It happens every two years and brings together the authors of CEN standards, the authors of daylight calculation software, the research community working on the effects of daylight on productivity and well-being, and the authors of guidance on the provision of daylight in design. There were also a few architects like me who tried to keep up with the science and not make fools of ourselves by asking really stupid questions, like, ‘what is the difference between lumens and luminance?’*

Some Conclusions

Over the two days I listend to a diverse range of speakers, from all over the world, many technical, some beautiful, all of them interesting. There were some particular highlights for me.

Daylight Autonomy, The CEN Daylight Standard draft appears to signal that the time has come to move on from Daylight Factor as a means of measuring daylight in architecture. Daylight Factor is a simple metric that predicts the amount of daylight in a room expressed as a percentage of the daylight available from an overcast sky. There are several problems with this.

Daylight Factor is not comprehensible to most people, including many professionals. It doesn’t relate either to the location of the space being examined or to the likely weather conditions in that location. So a room of the same size will achieve the same results in Iceland as in Uganda, despite the available daylight being quite different in the two locations. It doesn’t take into account the availability of greater amounts of daylight and sunshine available under typical weather conditions, so a part of the country where there is routinely a lot of sunshine will appear to perform as well as an area that has much less sunshine. As overheating becomes more of a problem, this is counterproductive. 

The CEN recommendation, based on several presentations during the event, is that we move to a measurement based on the availability of light in the room for a proportion of the day. This is similar to Daylight Autonomy, the US standard used in the LEED sustainable buildings assessment method. The draft CEN standard will suggest that we use a measure of the light levels in lux in the room expressed as the time that a desired light level is exceeded in a proportion of the space. The example given as a minimum is 300 lux in 50% of the room for 50% of the time. 300 lux is enough light to read, write or carry out office work, so it is adequate for many activities likely to be carried out at home. 50% of the space allow for variations in the lighting, particularly spaces only lit from one side. 50% of the time allows for variations over the day, so a room that is well lit in the morning can still comply with the requirement, as well as a room that is well lit in the afternoon, or early evening.

The draft CEN standard suggests that there could be three levels of such a standard, a minimum, set at 300 lux, a good at 500 lux and a high at 750 lux.

Rendering with Daylight: A particular bugbear of mine is architectural rendering that shows interiors bathed with light, when in fact such light is either impossible or unlikely at best. This doesn’t do anyone any good. Architectural rendering has a purpose, but that purpose should not be to mislead the designer or the client. It was heartening to see a presentation of Keyshot, a photorealistic lighting tool that can interface quickly with the VELUX Daylight Visualiser. They are both written by Luxion and they are now capable of interacting with each other. The VELUX tool can check the daylight in the room and Keyshot can produce a verifiably accurate daylight render. It can also deal with materials,textures and artificial light, but the important point is that it renders daylight accurately so that designers can check what actual difference their design changes make to the spaces rather than being fooled by a rendering engine that allow the designer free rein with the amount of light available. (In case you think that software doesn’t mislead, and I am overstating the point, one well-known and widely used rendering tool allows the designer to make the sun bigger!)

Thought Provoking: Paul Bogard: The organisers, VELUX, like to intersperse the hard science with some thought provoking speakers, and this time there were two presentations, one at the end of each day. The first by Paul Bogard was not about daylight, but about darkness. His book, The End of Night concerns the fact that most children in developed countries have no idea what a starry sky looks like. I was lucky enough to grow up in a rural area where starry skies were often visible, and the full majesty of the universe could be felt by anyone coming outdoors after dark. Today there are few places in the Western world where this is possible without having to get into a car and drive long distances. Will we end up in a world where fewer children want to become astronomers because they are unaware of the possibilities, or fewer philosophers because they haven’t seen how small and insignificant we are in the grand scheme of things. Paul points out that much of the problem is caused by security concerns and homeowners and property owners being sold lighting systems that waste a lot of light, and don’t even provide good security.

Thought Provoking: Olafur Eliasson: The presentation at the end of the second day was by Olafur Eliasson an Icelandic artist who, among other works, has filled the Tate turbine hall with a sun, and put large chunks of Arctic ice outside a hall where one of the COP talks was taking place. Bizzarely, one of the delegates contacted him a year later to ask him to bring the ice to the next COP. He had to tell the delegate that sadly, the ice had melted, but that there was more available in the Arctic.

He presented his kickstarter project with Little Sun which aims to bring artificial light to countries where children currently cannot read or study after dark unless they use kerosene lamps. His talk was deeply contemplative, almost mystical. His use of language was amazing, given that he works in Berlin and was born in Iceland, so must use at least three languages every day to express the most complex of thoughts. Two thoughts that stayed with me are:

The Shaping of the world is the creative act, and not the work itself.

Cultural institutions allow people to share without agreeing.
* ‘Lumen is the total luminous flux emitted by a light source, and luminance is the amount of light emitted from a surface in a particulat direction’ Obviously!

Zero Carbon(2016) Exemption Proposals

The plan to exempt small sites from zero-carbon legislation strikes me as being a total waste of time, energy and money and I cannot fathom why DCLG are wasting their precious time (and mine if it comes to that) with it.

The consultation document can be read here. The main elements are
– The proposal is to exempt small sites from the Allowable Solutions element of the Zero Carbon(2016) proposals. That is, the CO2 offset payment for that CO2 not mitigated on site by the development multiplied by 30 years multiplied by the agreed cost of CO2 per tonne.
– The consultation seeks views on the proposals including
The definition of small sites
Whether the exemption should relate to developers who are small or to any developer developing small sites
Whether the exemption should relate to Allowable Solutions only or whether the exemption should relate to Carbon Compliance as well
How long a time-frame the exemption should last for.

The problem I have with this is: where is the evidence that this is going to promote development? I haven’t seen any. Figures from the consultation document point out that 10% of planning applications in the UK measured by unit number were for single dwellings. That amounted to 24,000 units. So that tells me that there is a lot of activity in this sector and we can expect that to continue.
The Allowable Solutions impact of about £2-3k per plot will act as a small disincentive to development, but since many of those applications (my conjecture) are for the people who will actually live in those homes, the additional costs can be weighed against a lower cost of living for the occupants. The savings in fuel bills over the lifetime of the dwelling will pay for the relatively small additional cost. This is a calculation that many people will be able to do, and probably will realise that if they increase the build specification slightly they will reduce the Allowable Solutions costs and save themselves even more money. This seems to me to be a virtuous circle. People build more efficient homes for themselves, and they save money over and lifetime and there is less CO2 produced. This sounds like a market actually working. So why does the Government think that this is a market they need to interfere in before they actually have it in place?
The likely time frame would be from 2016 until the next issue of the Building Regulations, around 2020. This would allow the costs of the Zero Carbon (2016) to drop and the costs of Allowable Solutions to be absorbed. Again this seems to me to be counter productive. The way to reduce the costs of the Zero Carbon (2016) standard is to have everyone use it as soon as possible. This will bring down the cost of the insulation and window products that are needed to reach the standard, and then they will be available to all and not just the large housebuilders with very cost-effective supply chains. This proposal risks creating a two tier industry with higher costs of smaller builders and lower costs to larger builders.
The problem lies with the speculative nature of so much of our housebuilding. The builder of some of these small plots doesn’t know who the buyer has, and therefore has no interest in how that buyer lives in the home. There is no way for the lower costs of living in a more efficient home to be passed on to the developer in a beneficial way. A developer cannot build a more efficient home and offer it on the market for a small premium, this benefit is simply not recognised in the valuation of a property.
So, can I suggest that a more effective way for the Department to spend its time and mine, would be to investigate ways of making the speculative housing market function as a better market instead of trying to undermine those elements of future legislation that are likely to help it to function as a better market. But in an election year, perhaps that is too much to hope for.

World Sustainable Building 2014 (Barcelona)

The Summary:

This was an enormous conference with a concentration of expertise on sustainable buildings unlike any other conference I have attended. The messages from the conference were many, including the following which particularly struck me:

– we have too many different approaches to sustainable buildings across the EU, we need to coordinate approaches to make training and cooperation easier, this does not mean simplify! But there are some elements of different approaches that can be standardised to give a stronger platform for the other areas that need development. For example operational energy calculations could be standardised, but embodied energy tools are too early in their development to do this yet.

– our approaches to sustaianbility are often impenetrable to people outside the confines of specialisms. A result of this is that around 1% of the new buildings in Europe are given a sustainability rating at all. We need to make our language and approaches more comprehensible to the end user and to the market.

– LCA in particular is complex and time consuming, and the results are not always useable. We look forward to the wide use of EPD’s.


The Detail

This was my first visit to this conference, there were 1400 delegates  from around the world, many from Spain, a lot from the EU, but also from Hong Kong, China, India, Korea, the US and many more. I was mainly there to attend a meeting of the ActiveHouse Alliance. This is a pan-European alliance of companies and organisations working towards a better definition of sustainable buildings using Comfort, Energy and Environmental scores as a rating system. I am on the Board Advisory Committee which means that I am helping to guide the direction of the standard, having beein involved in the design of the first two homes constructed to meet the standard in the UK.

The conference spanned three days, I attended for the first two.

On the first day we held the ActiveHoues BAC meeting and on the morning of the second day we held an ActiveHouse Symposium, bringing together some of the research that came from the first completed projects across the EU. The sessions included observers and commentators as well as presentations from the projects themselves. I summarise here some of the comments and ideas that struck me particularly, these only represent a tiny fraction of the ideas presented, and the sessions I attended on the two days only represented one sixteenth of the sessions available!

ActiveHouse Symposium

From the ActiveHouse Symposium one particular comment that has stayed with me from this session is from Nils Larsson from IISBE, Canada, who said that ‘individual family homes cannot be described as ‘sustainable’, because a single dwelling cannot cover the breadth of the idea of sustainability. A single family home can be described as ‘energy efficient’ or ‘low energy’ but not ‘sustainable’’. I broadly agree with this, but I think that a single family dwelling can support ‘sustainability’ or ‘promote’ it but it cannot achieve it on its own.

Prof. Dr. Berndt Wegener from Humboldt University of Berlin, spoke about well-being from the perspective of a social scientist. He declared that the factors that lead to well-being can be measured,, but that they cannot be prescribed in advance. We cannot say that by doing ‘x’ we will definitely have ‘y’ benefits in terms of well-being. Pete Halshall, from the Good Homes Alliance, noted that feedback from residents shows that social tenants sometimes feel less ‘well-being’ than private tenants in the same building. There are other factors to well-being than those catered for by the built environment.

Stefan Haglind of Skanska wondered whether we should talk less about our impact on Nature, and more about Natures beneficial impact on us. If we understood better the effect on our sense of well-being and on our productivity of having better daylight, a nice view, comfortable temperatures and control over our environment, we would design better buildings and find it less difficult to have arguments about whether to adopt ‘green design’ or not. Studies, including the recent World Green Building Council report, show that there are considerable financial benefits to productivity from all of these features of well-designed green buildings that far outweigh the cost savings of lower energy use. I agree that we should emphasise the positive impacts of Nature, but I wouldn’t want to remove focus away from the catastrophic damage to our biodiversity.

Stefan pointed out that, for workplace productivity, the benefits from green buildings tend to be worth 100 times the value of energy savings. I wonder if there is a similar metric for the homes we live in? I can see a straightforward connection through home-working, our productivity at home is worth even more to an employer since the workplace is usually given for nothing. We can extend this benefit to the health service if we say that the home either promotes better health by being well-designed, or being sufficiently adaptable to enable residents to recover, or to be cared for, at home rather than requiring an expensive hospital bed.

Renata Hammer and Peter Holzer from Vienna provided some useful feedback from a small project where they had used the ActiveHouse tools for a small project with a private client. Their comments included:

-using primary energy as an indicator suggests that PV can compensate for other failings, and while this may be true for energy, it is not true for other environmental impacts. In this particular situation PV was inappropriate due to the heritage nature of the surroundings, and there was a lot of overshadowing, so in some situations this compensation is not even available.

-carrying out LifeCycle Assessments is a nightmarish process, and expensive in terms of the time taken to do so. (This was a recurring theme in the conference, with some speakers hoping that a production of many EPD’s over the next couple of years leading to a much easier set of data for designers and less technical people to use in their decision-making)


New Envelopes for Zero Energy Buildings

In a later session on ‘New Envelopers for Zero Energy Buildings’ there was a series of investigations into the LCA’s of different wall types. Erin Moore made some interesting points about the embodied energy of our buildings:

-that our current understanding of the relative amounts of embodied energy in our buildings is limited. Some studies put the amount of embodied energy as high as 50%, or as low as 10% of the total CO2 emissions of the building over its lifetime. She noted that the definition of ‘lifetime’ makes a big difference to the calculation, and that this figures varies widely around the world’.

-that the mitigation of emissions from embodied energy is more difficult than it appears. For example, can we claim that the embodied CO2 emissions from a home in the UK can be mitigated by putting PV on the roof? If the original emissions were from a country with a higher CO2 factor in the Grid, or if the original emissions were partially in China, how can we mitigate the damage in the UK? If some of the impacts are not CO2 related, but relate to a biodiversity loss, how can we deal with this where materials move from country to country?




Assessing Microclimate in Urban Environments

“People, life and vitality are the biggest attractions in a city. We see it in the choice of peoples seating, where the most populated benches are located, how people choose to sit on sidewalk cafes facing the people walking by rather than the buildings behind them.
The biggest quality of a sidewalk café is simply the interaction with other people. Do you have a choice between walking through a deserted, empty street and a street with other people walking, people will choose the liveliest street that provides them with more experiences, visual variety and a feeling of safety.” Jan Gehl 2002

This quotation from Jan Gehl, and many others like it, have brought home to the design professions how much we had moved away from a human-centric design philosophy to a building-centric and car-centric design philosophy for much of the 20th Century. Even now we are still living with many of the mistakes made in those decades, a car dominated lifestyle, buildings that don’t address the street, housing with high level access walkways, large highways that unsympathetically cut through historic urban fabric, the list is a long one.

Considering the human impact of buildings and the quality of spaces between them means that we should spend much more time considering, drawing and analysing these spaces than we previously did. The tools are now more available to analyse these spaces than ever before, now we just need to use them more often. Here are some examples of the tools available and where to use them.

1. One can use tools like IES to assess the Wind Microclimate between buildings. The tool uses historic weather data to predict the wind conditions between buildings by calculating how the shape of the buildings that are there already and that are in our proposals will affect the wind speeds throughout the year. This calculation is usually carried out at pedestrian level because that is where the pedestrians are, as well as at higher levels where people might sit on balconies or on roof terraces. The results are compared against the Lawson criteria for pedestrian comfort, a scale that compares the type of activity with the prevailing wind speed. Activities such as sitting outside cafes and window shopping are suggested to be best places where the Beaufort Level 3 ‘Gentle Breeze’ is not exceeded for more than 1% of the time in a simulation. It is a notable failing in the Lawson Criteria that it doesn’t adequately deal with cycling and ‘windiness’. Cycling and wind are are particular problem as this combination presents a risk to life where cyclists can be blown into traffic by sudden gusts of wind, a problem not normally faced by pedestrians. Any suggestions by readers as to what an appropriate criterion would be are welcome.

2. IES can also be used to assess the solar irradiation on roofs to highlight locations for renewable energy systems, helpful in determining whether some buildings overshade others or whether some roofs will get ehough solar insolaton to make it worthwhile putting renewable systems there art all.

3. One can use ENVI-met to carry out a similar assessment, but with the additional sophistication of assessing the impact of planting and street trees on the local environment.

4. We can use ECOTECT to evaluate the solar incidence on the facades of buildings to tell us whether the cafe will be in sunshine for long periods of the year and whether people will get too hot sitting there and whether we should provide an awning. Ecotect is useful for many other type of analysis as well, but its imagery for this type of use is particularly helpful.

5. We can use simple tools like SketchUp to look at shadows cast by our designs at a early stage to assess the impact of one design versus another by comparing the impact at the equinoxes and solstices. This is paricularly helpful as it can be done easily and quickly by the designer in the tool that they are woring on (assuming that they are using SketchUp for early stage designs) and gives them immedate feedback. The other tools used here are for more specialist use and are typically used by consultants who specialise in this type of analysis.

6. There is a substantial piece of work being carried out at MIT to develop a suite of tools for urban design analysis based on the Rhino modelling software. This suite is intended to include tools for early daylight, energy and embodied energy analysis. It is still a work in progress but highlights the level of ambition made possible by readily available computing power. An example of the progress to date is the DAYSIM engine used for modelling daylight in and around buildings.

These are just some examples of the tools available to investigate whether the spaces we are creating between and around our buildings are going to be fit for purpose and enjoyable to use. Here is an example from the Kings Cross masterplan of a very successful intervention, a set of sout-facing steps connecting to the canal. It was popular before the astroturf was added, being a sheltered and sunny place to sit and chat, drink a coffee or eat lunch, now it is both sunny, and more comfortable to sit on.


Sitting in the Sun

Sitting in the Sun: Kings Cross

Construction Material Selection

There are three types of materials used in the construction of buildings. Those that are harmful to the environment in their production or use , those that are harmless and those that we aren’t sure about. There are  a number of methodologies for assessing materials and their use and many sources of information. I thought that it would be useful to summarise these in one place.

My view on this topic generally is that we have put it into the ‘too difficult to think about now’ box because there are no compelling reason’s to do so. There are no regulations to direct us in this matter, and there is no link to the market to tell us what the end users of our buildings want from us. I am convinced that a normal occupant of any building would be concerned to hear that there are materials used in the construction of their building that can be damaging to their health in any circumstances, but we make little or no effort to ensure that our buildings are as benign as possible for the occupant, and make no effort to communicate about it to the market. It is a specific area of market failure. If we compare the construction market to the food market, there are substantial efforts in the latter to explain to consumers what goes into their food, where it comes from, and concerns about health of consumers and farmers has largely led to the growth of the organic food market with no external regulation.

For BREEAM and Code for Sustainable Homes projects, there are guidelines to follow in the form of credits for Materials, which will point us towards the BRE Green Guide to Specification for Materials, which provide us with an A-E rating for the material in question. However it is not immediately obvious to any observer how or why the rating is given. There was a lot of concern in the industry when UPVC windows and timber windows were both found to be capable of scoring the highest rating. This is despite the fact that UPVC windows produce a lot of dangerous chemicals when burned. This demonstrates the benefits and problems of such simplified rating systems. If the analysis is sufficiently broad, almost any material can be found to have some advantage over another.

At the other end of the spectrum there is the Cradle-to-Cradle methodology which is really only interested in where the material came from, and where it goes after it has been used, it doesn’t concern itself with the operational phase at all. The Cradle-to-Cradle philosophy tests materials for either being sources of biological nutrients, in which case they can be composted, rotted, or otherwise consumed after use, or they are technical nutrients in which case they can be reused. In the case of composite materials the process for separating the two materials needs to be considered.

Both of these methodologies rely on a technique called LifeCycle Analysis (LCA). This aims to assess the impact of the material on the environment during its production, operation and recycling or reuse. LCA tools help to smooth the process of analysis by providing databases of material properties and impacts for the analysist to use, and lowers the costs of carrying out analysis. There is an ISO standard approach to LCA described in ISO 14044.

When selecting a material for use, you should ask yourself the following questions:

– is the material obviously harmful to the environment, to its producers, constructors or end users? The REACH database will help you to identify if it is a banned or harmful substance.

– How do I compare two similar materials? When comparing two similar materials check whether either one has an Environmental Product Declaration (EPD) which is a report on its LCA. If both have one, then you should be able to compare the two materials.

– How do I compare one construction system to another? If the construction system you are using the material in has a Green Guide rating, then that will enable you to compare it to other similar systems using the same material.

– Am I worrying too much about small stuff? You can use a tool like eTool to test the overall impact of using one material in the building compared to another material, which will help you to assess the total impact. Otherwise there is a danger of spending a lot of time worrying about the wiring, when the main impact will come from the construction materials.

The field of material impacts is growing rapidly as we learn more and more about the harmful impacts materials have on us and on the environment around us. There is an increasing number of tools and protocols to help designers, contractors and clients to understand the materials that they work with every day. We shouldn’t wait for regulators to tell us things that we can already find out for ourselves, and our end users will be grateful that we took the trouble to make their buildings safer and more environmentally friendly.


Cities 2.0 TEDx London

I was lucky enough to attend TEDx London last week on the subject of Future cities. 13 speakers from a wide variety of professions and interests talked about what is wrong with our cities today and how we could make them better tomorrow.

Michael Batty from CASA talked about connected networks and demonstrated that there are about ten large-scale well-connected areas in the UK that can reasonably be called cities. He discussed population growth and posited that we are likely to stabilise population around the 10 billion mark as developed economies halt population growth and stabilise or reduce. We are going to hit the point of being 75% urban around 2050, which will add a further 2.5 billion people to urban environments, almost as much as we currently have.

Katherine Harborne, a Conservative Councillor for Richmond, talked about how cycling can contribute to the future of healthy happy cities by allowing citizens to commute quickly, safely and cheaply. I don’t think there was any dissent there, she was preaching to the converted. She pointed out that the more cyclists there are the lower the death statistics are on average. This is a nicety that only a scientist would think was positive. To the rest of us a death is a death is a death.

Tom Wright from the Regional Plan Association in NYC had a lot of interesting experience in the US to talk about. The US is moving back towards an urban model and away from the suburban one. The rate of car use peaked in 2005 and is continuing to drop annually. NYC has just brought in a cycle hire scheme and it has already surpassed the number of daily trips taken in London. (But we don’t care about that because we are not competitive, Yank) He discussed the way that cities lever taxation to build infrastructure, something that we don’t seem to have a grip on in this country. It is commonplace in the US to use local taxation to pay for infrastructure such as roads, bridges, tunnels etc., by using the cheap finance that a city can buy. He discussed the uplift in local values that can come from improved infrastructure and wheter that increase in value should be used in part to pay for infrastructure, a type of local Value Added Tax, or Stamp duty land Tax.

Jonathan Keeling from Pavegen showed us his company’s clever paving system that generates electricity. The memorable fact from him was that if 100m of Oxford Street was paved with his technology, the power generated in a day would keep the Oxford Street lights on for a week. Now if he had said that shoppers would also be less tired, happier and less stressed as a result, then he would have had our attention.

Michael Pawlyn, formerly of Grimshaw’s and a major influence on the Eden Project talked about biomimicry, and how learning from nature can help us to make the best uses of scarce resources. I love his presentation technique where he films himself drawing diagrams and talks over it. He showed a beautiful office building which encapsulated many of his ideas on how to design well-lit, enjoyable spaces. I’d like to see him take his ideas direct to manufacturers and get them to design some new products based on them, rather than trying to encapsulate all of them into a single building.

Vanessa Harden talked with passion and humour on the subject of engaging with communities through guerilla gardening. Her apparently casual performance belied a serious purpose to help people to engage with their communities through nature using faux spy technology.Her gardening tools for busy professionals are particularly good.

Mischa Dohler won the prize for entertainment, if there had been such a prize. His conflation of sexual mores and data gathering was very polished and wouldn’t have been out of place in a comedy club. His debunking of the myths around ‘Big Data’ possibly made more sense to him than to most of the audience who haven’t been exposed to those myths yet. I daresay that is what happens when you are close to the leading edge, no-one gets your jokes. His most memorable section was showing how difficult it is to ask Londoners about their city and how they engage with it. No-one would stop to answer the question!

Suzanne Holt Ballard talked about a near future city where we are going to be able to control systems and link to them through brain-to-brain (B2B) interfaces. She wondered what a city would be if we could connect to it without actually being there. We nodded and applauded as though we had understood anything she had said.

Roma Agrawal, spoke convincingly about the need to encourage young people to become engineers. Like scientists there is a lack of role models for a younger generation to make them want to join the engineering and design professions.

Leo Hollis spoke convincingly about the nature of cities as places for people to come together and interact. He cited a study into urban manners or ‘civiity’ which compared a rural village to a suburb to part of LB Newham which found that people were more civil in Newham than in the other places, mainly because they had opportunities to do so. Little England and the suburbs are places for people to get away from each other, cities are places for us to get together.

Alexander Grunsteidl spoke convincingly about how cities evolves as places for defense initially and then for retail. He wondered what would happen to cities if we moved more of our purchasing to online shops and if this resulted in the closure of large sections of our high streets how would we react? He wondered if we all became traders again as we were in the early stages of cities, and traded and shared with each other more through technology, and bought less from distant shops, whether the city would reform itself around this?

Finally we had Roger Hartley from the Bureau of Silly Ideas. This crew bring a range of engaging interventions to streets, markets, festivals, building sites and other opportunities at the drop of a silly hat. I particularly like Roger’s plea to stop surrounding sites with enormous hoardings that turn a place into a sort of black hole while the hoardings are there. Be more creative with sites, they are often there for along time.

Engineering Plant to Suit the User or Policy?

I had an interesting chat with an engineer over the weekend; an engineer responsible for managing boiler plant for landlords. Among other schemes he is responsible for the hot water plant on one of HTA’s recently completed schemes. This is a scheme where we did the working drawings, but didn’t do the original design.

His summary of the plant performance was startling. The scheme has four gas boilers and a gas-fired CHP. All installed to meet planning targets. So far so good. I asked him whether the CHP had been switched on yet, and he shook his head, and said, “and neither has three of the boilers”!

We are well into cold weather and this scheme hasn’t needed more than 20% of the available heating plant turned on to meet its entire hot water and heating demand. This suggests to me and him that there is something rather wrong in the process when this can happen. If we over-designed in any other dimension by 80% it would be obvious to everyone, but in heating plant it is somehow invisible?

The engineers view is that M+E design codes and practice hasn’t caught up with modern fabric standards, or modern living patterns. We are routinely designing for heating demands that aren’t there. Solar gains and equipment gains are often enough to heat modern apartments and most people in dense apartment schemes never actually need to turn the heating on. meanwhile we have built a boiler too big, with circulation pipework that is too wide, and radiators that are not needed.

He points out that many ‘design’ engineers are involved early on in the process to specify systems, and these are then handed over to a M+E installer who will usually value engineer down the system as much as possible, but will still install it to meet the performance targets specified at the design stage. This is at least partially about insurance, as the design risk will remain with the design engineer. So the final design may have little to do with the performance of the actual building, or the actual energy use of the occupants.

None of this is sustainable. Sustainability is not just about the standards of the things that you do, it is also about assessing properly whether you need to do it at all.

Sustainability Rating Tools

I participated in an interesting debate during the week at Derwent’s White collar Factory, chaired by the UK Green Building Council. The topic was ‘whether we need rating tools to advance the sustainability of the built environment’. I took the opposite view, more from the need to create a debate than from conviction, but as always, taking the contrary view was helpful to crystallise my thinking about what a sustainability rating tool should be rather that what they currently are. This is all very relevant to the current situation where DCLG seem intent on abandoning the Code for Sustainable Homes without consultation, and without replacing it.

My thoughts on sustainability rating tools are that we need them but we could do with some better ones than the ones that we currently have. In case you are not sure what rating tools I am talking about here is a list of the ones that we at HTA currently employ on one project or another. BREEAM New Construction, Code for Sustainable Homes, EcoHomes, ActiveHouse, BREEAM Communities, and a couple that we have developed ourselves: we also use energy assessment tools that some people think are sustainability tools but aren’t, like SAP, SBEM and Passivhaus, all of which suffer from the same problems as sustainability rating tools. The main problems that I have with the current crop of tools that we use are as follows:

-I don’t think that rating tools should tell professionals how to do their job. They are paid enough to know that already, and there are many mechanisms in place to spread best practice, there is no need for rating tools to do that job.

-Rating tools generally focus too much on environmental criteria to the exclusion of financial and social, and this is a big mistake. Ignoring the financial impact of measures is what has led to the Code to be on the verge of being scrapped. Housebuilders see it as adding costs but not adding any value. Their view is that Code homes don’t sell for any more than any other home, so there is no benefit to house-builders in following it. Government pays more attention to them because they have a big impact on the economy. If the Code was seen to be making new homes more attractive to purchasers, or attracting a premium value, then there would be no argument about applying it. We need to join up the thinking between environmental, social and economic sustainability.

-Rating tools tend to be written by a narrow group of people, mainly those with a strong interest in environmental matters, which leads to a narrow focus of credits and measures. Tools need to be relevant to a wider section of society and encourage high quality design that takes into account the needs of the wider population.

-The costs of running the tools and the frequent costs of retraining all need to be lower. These costs are a barrier to entry and don’t help to get tools more widely used.

-The assessments carried out using the tools tools should not need to be verified independently. Professionals are paid to do a job, and they should do it properly. A proportion of assessments should be independently audited, and poor assessments should have the rating taken away from the client. This would improve quality and lower the costs of carrying out assessments.

-Tools must look at the building a year after occupation and assess whether measures are working or not. We don’t have the luxury of continuing to install equipment to meet the requirements of a rating tool when we know that the new tenant/owner will come in and remove them. If the measure isn’t working then the tool needs to change immediately, not years later.

-Finally, rating tools should focus on the outcomes, and not on the process. Targets should be set that are measurable, and the project team should work out how best to do the work. Targets such as Fabric energy Efficiency, CO2 emissions, sound reductions, daylight factor, space per occupant, embodied energy per occupant, air quality, occupant satisfaction, hours of overheating, and so on are all measureable and there are tools or processes available to do this. I use the ActiveHouse manual as an example. Its less than 10mm thick and contains all the elements of a good rating tool. That doesn’t make it easy to meet it, but it does make it possible to understand it.

Hmmm, maybe I should write my own…