Archive for the ‘Recommended’ Category
As the next set of “improvements” to Part L of the Building Regulations gets nearer, some of the counter-productivities that the current rules throw up will, to my mind, move from being ‘just a little strange’ to cynics like me, to become serious problems.
To begin with, what level of CO2 emissions reduction from buildings will these new rules actually deliver? Well with 99% of buildings being immune from these revisions (because they’re already built) the best we’re looking at is a 1% improvement in the short term. The new rules will only be raising an already high bar – “making the best better”. As it is average emissions we’re interested in, shaving a few percent off the best performing properties i.e. new builds, will have almost no effect on total emissions in the short to medium term. Besides, all houses, both old and new, will be zero carbon in 2050 anyway as by then fossil fuels will be too expensive to burn!!
Ignoring the very real questions about value for money (which few believe lies in squeezing out the last 10% of CO2 emissions from the best performing buildings) I want to explore how a narrow focus on new buildings, without wider consideration of external energy issues, could actually push up CO2 emissions. It seems likely the further revisions to Part L will lead to two technologies in particular getting much more common in new build; these are Air Source Heat Pumps (ASHP) and PhotoVoltaics (PVs). I don’t want to talk about the illusory CO2 savings these technologies may or may not deliver, but rather self-evident facts that are not part of manufacturer sponsored ‘independent’ studies.
ASHP’s are a type of electric space heating; efficient maybe, but electric none the less. And, like all heating solutions, are required to work harder the colder it is. Because there is no requirement for ASHP to be combined with underfloor heating, most systems will be installed with radiators or as air to air to heat pumps. Air to air heat pumps are ‘on demand’ heaters, as are air to water heat pumps if combined with radiators (though to a lesser extent). That demand is going to be predominantly winter mornings and evenings. So, as more and more systems are installed, it will have the effect of increasing peak electric demand, compared to the gas heated alternative – I’ll come back to the gas use later.
Fortunately, (according the Government’s calculations) this increased electricity use can be offset by the installation of PV’s – well here’s the rub; it can’t. It is beyond dispute that PV output on winter mornings and evenings is effectively zero and that the electricity they generate during the summer months is used immediately, within 1/50th of a second of its creation. Therefore, this increased winter demand has to satisfied by some other technology. Wind is simply not reliable enough, nuclear is a base load technology so that just leaves our only other clean(ish) grid generator – gas. Here’s where the sums get interesting. A gas power station will turn 100 kWh of gas into about 40kWh of electricity which is then fed into an ASHP that on those cold winter nights will struggle to turn it back into 100 kWh of heat. So… billions of pounds spent on new power stations and heating systems and the amount of gas (and CO2 ) saved? Zero at best.
The fundamental problem is just about everyone concerned in the Part L revision process assumes wrongly that every kWh produced and consumed has a equal CO2 loading. It doesn’t. Furthermore the idea that the grid can be used as a battery only really works when nobody is actually using it as such. Generators are required to hold spare generating capacity above predicted peak levels, to be called upon if there is, say, planned maintenance or a breakdown somewhere. The problem is that as the network gets older, due to a chronic lack of investment since privatisation and more renewables being added, the likelihood and size of these breakdowns grows. Remember, every night PV’s are effectively ‘broken down’, making the grid increasingly vulnerable to outages at time of peak load. Unfortunately, renewables and peak electric heating (ASHP’s) make matters worse by increasing these peak loads. Therefore, over the coming years as peak time vulnerability increases, power company’s will have to build extra generating capacity that will only be running very inefficiently for a couple of hours in the evening. PVs on the roofs of ASHP heated houses will do nothing to alleviate this problem and if the PVs are used to justify the use of electric heating will actually make matters worse. Until these undeniable facts are faced up to we run the risk of wasting billions on technology that only give the illusion of CO2 savings.
Maybe the fact these revisions will not affect the vast majority of the building stock is not such a bad thing after all.
Steve Maslin, bud www.buildinguserdesignsolutions.co.uk
I believe that social and economic sustainability are critical to achieving environmental sustainability. As with wildlife conservation, if we ignore the people within that environment, then we will fail to achieve our environmental /ecological objectives. As an architect, access consultant and someone who worked within social provision environments I am what might be best described as a social sustainability practitioner, providing advice in order to achieve positive and sustainable user experiences of built environments.
The User Experience
I also believe that there is an intrinsic relationship between real building value and the quality of the user experience. Premises that fail on a social and economic level are, I believe, intrinsically dysfunctional and plainly unsustainable in the long term. Either they are so bad that they get pulled down earlier than their predicted life expectancy – or they continue to subject the majority of their occupants to low level deficits of functionality with regards to wellbeing, health, productivity and economics. For some individuals, especially disabled people, socially dysfunctional buildings become serious impediments to their reasonable expectations for sustainable social and economic life choices – see http://odi.dwp.gov.uk/about-the-odi/the-social-model.php.
If we focus solely on the environmental factors we will not achieve the end goals for the environment and could ultimately miss out on buy-in from society in the long term and ultimately miss the point of why we (the planet’s occupants) want a sustainable environment to live in and in which we need to function socially and economically. Without social and economic sustainability factors being taken into account there is also a greater risk that assessment of environmental factors alone runs the risk of conflicting with legitimate and relevant social and economic criteria and provision.
Management and Information
There is also the matter of management and information. In the field of access and inclusion there is a tendency for those who aren’t access consultants to focus on physical provision and to neglect the wider significance of management strategies and information strategies. A similar paradox exists within the broader subject of sustainability. Understanding people’s needs increases our understanding of the management and information strategies need to be implemented, not only to achieve inclusion, but achieve social, economic and environmental sustainability as well.
Form Follows Function
We could refer to the architectural maxim of “form follows function” and describe the “function” of a building as being social and economic and that the “form” a building then takes being the outcome achieved within a particular environmental context. However this is where there is a risk of neglecting evidential information pertaining to social sciences and sustainability. This is, because in the first instance some social factors can be perceived (by some) as intangible and not what some might consider as “objective” and about “function”. Take for example, within the realm of inclusive design, access matters ought not be confined to access for people who have mobility difficulties alone and ought to extends to sensory and neurological needs as well. Some may, at first glance, think neurological needs have few tangible implications for building design. However, academics and social scientists working fields such as environmental psychology can point to there being significant evidence as to neurological and psychological factors, relevant to the population as a whole, impinging on how well built environments function.
Schools as an Example
Take for example The University of Salford’s Study into the effect of classroom sizes of children’s performance -see: http://www.salford.ac.uk/home-page/news/2012/study-proves-classroom-design-really-does-matter. One therefore questions whether school buildings built under reduced space standards as proposed by the current government are sustainable, quite apart of from the detrimental effect one suspects it will have for children with mobility difficulties or children on the autistic spectrum? How long will it be before such buildings are pulled down?
When seeking to achieve sustainability, one would suggest that we resist the temptation to focus on pre-conceived outcomes. Greater social sustainability is partly achieved through guidance and standards, but more particularly through process – i.e. procurement, stakeholder engagement and brief development. As with environmental sustainability, it is often the processes that designers use to arrive at their proposals that determine the ultimate success of what they are doing. If processes do not anticipate management implications of designs through appropriate procurement, stakeholder engagement and brief development processes then the chances are that the design will not function in a socially, economically and environmentally sustainable way. If decision makers are only asking the question “where does it say that I have to?” …they invariably haven’t quite understood the subject. If they are encouraged to follow a collaborative and thoughtful process, then they are more likely to know why they ought to do something, because they understand the implications of their decision. In turn, they are more likely to sustain this understanding during occupation of their premises or when undertaking yet further projects.
Cath Hassell, ech2o consultants www.ech2o.co.uk
We all know the high environmental load of traditional swimming pools; the energy required to heat them; the chlorine required to keep them clean; the large amount of water that is required to fill them in the first place and refill them after they have been drained down for the winter. It’s also common knowledge that a designer can ensure a pool is more sustainable by specifying a pool cover, installing solar thermal panels to heat the pool and considering ozone instead of chlorine as the disinfection method. But all of that does not need to concern us in the environmental building sector because if a client wants a pool, there is a perfect solution available on the market and that is a natural swimming pool. Right? Well wrong actually!
I was recently asked to provide a critical analysis of the water strategy for a large multi-million pound dwelling that, as with many such sustainable properties, had not addressed water beyond rainwater harvesting and dual flush loos. On first reading the one thing we didn’t have to worry about was the swimming pool as it was going to be a natural pool. But when we began to analyse the pool specification in detail some worrying facts emerged.
Natural swimming pools
A natural pool consists of a swimming area and a planted area, (the filtration zone). The plants extract any nutrients that run into the water, thus restricting the growth of algae. A pump is used to circulate the water through a filter to aid cleaning. Natural swimming pools have several environmental advantages; no chemicals are required to clean the pool, thus preventing the formation of hazardous chemicals; they do not require draining down over the winter and refilling in the summer, thus saving water; they use less energy as they are not heated; they provide a habitat for insects and amphibians in the shallow planted zone; and birds use the pool for drinking and bathing.
Natural pools are often designed to be larger than a traditional pool; in this case a surface area of 124m2 (compared to an average traditional pool size of 45m2). You would assume that a natural swimming pool would be quite happy (indeed prefer) to be filled with alternative sources of water to mains water. However, when we asked about filling the pool from the commercial fish ponds on the site we were told the nutrient levels in the water would be too high. So this pool would require 153m3 of mains water to fill – the equivalent of a daily use of 420 litres of water for a whole year! We asked about topping up with rainwater from the green roof and were again told that nutrient levels would be too high even though no fertiliser would be used on the roof.
Evaporation, even from an unheated pool, is significant. Calculating evaporation rates is complicated, with many variables. The main factors that affect evaporation rates from domestic outdoor pools are pool surface area, temperature difference between the water and air, humidity levels and wind. Research in Australia has shown that the average daily evaporation rates from an unheated pool are 6.4 mm/day (6.4 litres/m2/day) for the six hottest months in Melbourne. The same research shows that a pool in Perth, in the coldest months, loses 3,000 litres a month over a surface area of 42m2. In the absence of any comparable data for the UK I calculated evaporation rates from the pond using both sets of data (with changes to better reflect UK conditions) and came up with some depressing figures. With a pool surface area of 124m2, and a rate of 2.1mm evaporation a day, 260 litres a day is lost to evaporation (against the average water use in the UK of 150 litres/person/day. Over four months this is 31,200 litres (31m3). Adding evaporation across the remaining eight months of the year (albeit at a lesser rate) total yearly losses are over a third of the pool volume. So far, so bad, and it gets worse… To keep the pool clear the water is continuously pumped through a filter. A pool this size will require a pump drawing 400 Watts. That is 3,504Wh of electricity a year, the average household’s total electricity use!
So am I saying no ponds at all? No, of course not. That would make for very poor garden design. But these highly engineered natural pools are not the solution. On this site, the response by the architects to our findings was swift and decisive. They reduced the size of the pool to 45m2 for the swimming area with a planting zone of 12m2, cutting evaporation rates, original fill water and electrical load by over 50%. And although the natural pool is currently still in the specification, the architects agreed to our suggestion to provide a natural pond as well, filled and topped up with rainwater from the green roof. The level of the pond will rise and fall with the seasons and the available rainfall. Any overflow from the pond will drain naturally into the ground via swales and rain gardens. A natural pond increases the biodiversity on this site as well as providing another focal point, and uses the runoff from the roof in the best possible way.
 The size of the planted area depends on the pool type but most have a planting zone of between 15-25% of the surface area of the pool.
 Chlorine in pool water reacts with organic compounds in the water such as sweat and urine to produce a host of hazardous chemical compounds that include nitrogen trichloride, aldehydes
 Both of the main suppliers of natural pools in the UK stated this.
 As Melbourne in the summer is hotter than the UK, I used a figure of one third the evaporation rates (i.e. 2.1mm/day) and over four months rather than six months. Using the Perth data as it stands but for all twelve months, yearly evaporation losses would be 36m3.
Lucy Pedler Director, The Green Register
Last month one of our dear, long time Green Register and Steering Group members, Jim Allen, kindly wrote us a blog about the breathing wall concept and expressed his concerns about this method of construction, some of which I will try and address here.
The first point to make is that the term ‘breathing’ wall (or roof, floor or ceiling for that matter) is a pretty inadequate name for a very useful way of building that attempts to deal with a number of problems, namely: avoiding interstitial condensation, improving standards of work on site and employing the use of low embodied energy building materials. Jim is right in saying that walls don’t breathe – what the term suggests is that the walls ‘breathe’ large amounts of moisture in and out, much like our lungs do, which is not really the case.
Breathing construction is designed primarily to minimise or, better still, avoid interstitial condensation and it does this by using a combination of breathable materials and placing them in the construction build-up where their various values of vapour resistance will assist with moisture movement most effectively. This includes two vapour control layers – one either side of the insulation layer with differing vapour resistance values and I am not sure many people are suggesting throwing away the vapour barrier except perhaps in exceptional cases for some historic buildings.
The ideal situation would be that all external elements of a building would have a continuous, unbroken vapour control layer that remains intact throughout the building process and thereby keeps the moisture that builds up inside the building during use due to human activities (showering, cooking, breathing etc.) from ever entering the fabric of the building and causing interstitial condensation. This requires competent builders who understand why it is so important to maintain the integrity of the vapour control membrane. With the exception of a few (many of whom are, of course, members of The Green Register – searchable under ‘builders’ on our website list of members), this rarely happens. In my experience a building site is a messy place with lots of trades working around each other trying to meet deadlines and the opportunities for inspecting the continuity of the vapour control layer is quite limited. This can lead to breaks in this layer, the subsequent ingress of airborne moisture into the building fabric and resultant deterioration of the construction, sometimes behind the scenes where it can cause potential structural damage.
Jim’s reference to our Canadian cousins may well be to a World in Action programme back in the 1980’s which reported on the demolition of a timber-framed housing estate in Canada that was found to have damaging moisture buildup within the framing. The programme purportedly described how breathing construction principles had not been understood; the walls were wrapped on both sides of the insulation with plastic vapour control layers, site work resulted in holes in these layers, moisture got in through the holes but couldn’t exit because of the impermeable layer of plastic and rotted the timber which compromised the structural integrity of the building so they had to be torn down. Fortunately we now understand what went wrong with this housing scheme and breathing construction can help to avoid these problems in the future.
It is really important to understand that the principle of breathing construction accepts that there will be some airborne moisture entering the fabric – although this is always kept as low as is practically possible – but that, with a combination of breathing materials and intelligent use of vapour control layers, this moisture will be speedily and safely transported to the outside where it does no harm. It does not suggest that it is acceptable to have excessive amounts of airborne moisture entering the building fabric, only that that which does enter can exit even more easily.
Another misunderstanding is that breathing construction does away with the need for ventilation – this is a dangerous concept. Because only very small amounts of moisture are intended to pass through to the structure of the building, most of it needs to be extracted by one of the various ventilation methods we conventionally employ for non-breathing constructions such as natural or passive ventilation, trickle vents, windows, extract fans and so on.
I am completely in agreement with Jim when he expresses his concern for retrofitting insulation to buildings and the risks of interstitial condensation arising. I am writing this on the day that The Green Deal was launched (again) and, whilst being in the minority of people who think that this is a useful Government initiative with lots of potential, I am very worried about layers of insulation being installed in retrofit projects without a comprehensive understanding of what this does for the dew point and moisture movement. Our ‘All in The Detail’ one day seminar addresses this in depth – Jim attended this seminar and it may have spurred him to write his excellent blog.
Unless Green Deal installers have sufficient knowledge about the risks of interstitial condensation, the retrofitting of insulation onto existing building elements may be storing up problems for the future. But this is a surmountable problem. As Jim suggests, more research must be carried out with real life examples; additionally, training installers in this field will help them to understand the risks and the solutions to avoid moisture build-up in retrofit projects…and also avoid lots of court cases in the future.
By Jim Allen | E&M West Ltd | www.eandmwest.co.uk
… every move you make,” is an unforgettable lyric from a Police classic; these days it makes me uneasy whenever I hear it given its darker overtones. I feel the same way whenever people talk about breathing walls. If there is one subject that gives rise to confusion and mixed messages its moisture and vapour movement through walls. I’ve been fortunate to attend several CPD sessions touching on the subject, including one excellent day presented by Green Register.
I feel I have a tenuous hold on the concepts, and that some of my long-held beliefs (some may say prejudices) have been confirmed, others blown away, and questions remain. This is my take, yours may differ, tell me about it.
The breathing wall that whisks away moisture from inside the building like some giant passive air-conditioning machine is an attractive concept. Even better is the breathing wall based on organic insulation that squirrels away carbon. It can moderate our environment by absorbing excess moisture and preventing condensation. Why suffocate our buildings with the plastic bag favoured by our Canadian cousins? The new wisdom says the vapour barrier concept is figuratively and too often literally punctured; it can even be made redundant when internally insulating cold solid walls.
Well from what I’ve heard walls don’t breathe, certainly not through the wall in any meaningful timeframe. I may be old school but I can’t help thinking moisture in a wall is a bad thing, and excess moisture and organic materials generally don’t mix. Inorganics like clay, or lime with its biocidal properties seem much better bets if adsorption is what you are after. Even better, ventilate well and solve the problem at source. As for insulating solid external walls, it may be that the clever science and the barking WUFI*1 dog tells us this works, and in the lab and the theoretical model it might, but in the real world of the Green Deal with wholesale adoption of insulation specified by rote and not much intelligent design do we really want to throw away the vapour barrier?
We need new knowledge through research combined with old wisdom if we are going to get this right. The building physicists have yet to find their professional feet. Eventually the education system and professional institutions will get their heads around giving people the right tools and the right training. Until then all of us with experience in our respective disciplines need to be broad minded enough to reach out beyond our professional boundaries and acquire breadth of knowledge to take intelligent informed decisions on our client’s behalf. We must not abdicate decisions to those with a commercial axe to grind or whose main goal in life is following the Golden Rule*2.
*1 WUFI: program which allows calculation of heat and moisture transport in multi-layer building components
*2 Golden Rule: Green Deal acceptance criterion
Cath Hassell ech2o consultants www.ech2o.co.uk
Team GB delivered during the Olympic Games on their medal target, but what about water use? Does the claim of “the greenest games ever” hold up under scrutiny? The goal was a 40% water saving compared to 2006 industry standards, and although the “industry standards” were not explicitly stated it was an ambitious target that, if achieved, would certainly be impressive. When the Olympic Park Water Strategy report stated that: “…the Park in legacy mode is expected to exceed this target with a total 57% saving in water consumption”, you could almost feel the nation’s chests swell with pride. However, just as the mantra “delivered on time and on budget” falls apart when you realise that the budget for the Games was increased to £9 billion from the original £2.4 billion, predictions of reduced water consumption also need to be analysed more closely.
The 40% target
In 2006, WC flush was 6 litres maximum, urinal controls were mandatory, and taps in public washrooms were already time controlled, so a 40% reduction would require alternative sources of water as well as efficient appliances, and originally it was expected that would be mostly from rainwater harvesting. The preferred specification for appliances was 4.5 litres single flush WC, fan assisted waterless urinals, PIR operated taps at 5 litres/minute and showers at 9 litres/minute. All venues installed low flush toilets, and low flow showers and taps as recommended in the design brief, but the Velodrome and Aquatics Centre opted for flushing urinals. The Velodrome and Handball Arena installed rainwater harvesting and the Aquatics Centre installed backwash recycling. Rainwater harvesting is estimated to reduce the Velodrome’s potable water demand by 20% and predicted to generate a potable water saving of 530m3 a year. (However, with just 25m3 of storage and the fact that the stadium will be used so intermittently after the Games, this figure seems optimistic to me.) Recycling the filter backwash water for WC and urinal flushing is estimated to reduce water consumption in the Aquatics Centre by three per cent.
Where was the water used?
It was estimated that water consumption up to and during the Games would be 361 Mega litres (Ml). Post Games the figure is 5,735 Ml over the remaining 24 years design life. This meant that 6% of total lifetime water use would be during the Games. How that requirement for water was broken down is very interesting. I had assumed the greatest demand would be WC and urinal flushing from the estimated 3.7 million visitors, closely followed by the Aquatics Centre. But in fact, the Olympic Park Water Strategy estimated water consumption to be as follows: the Combined Cooling, Heating and Power Plant at 26.9%, Eton Manor at 15.6%, 7.7% for the Aquatics Centre and 7.5% for establishment irrigation leaving just 14.5% of water requirement for the remaining venues on the site which included the 80,000 capacity Olympic Stadium and the Press Centre.
I hadn’t even considered the process water requirement for the CCHP plant, but it made sense once highlighted. But Eton Manor, what was happening there? And why was so much water required for irrigation when most of the park was planted with wildflower meadows?
Water based hockey pitch
Hockey is played at Eton Manor on a water based pitch. Water-based synthetic turfs enable the ball to be transferred more quickly than sand-based surfaces and are less abrasive so reduce friction burns, but require a lot of water as the pitch is flooded with water before the start of every match to a depth of 3mm. With a playing surface of approximately 6,000 m², and top up required at half time, water use averages 26 m³ per match. Added to this is the fact that the pitch has to be kept wet constantly and, to prevent the growth of algae, hydrogen peroxide is added to the water. As the Intentional Hockey Federation themselves (back in 2006) suggested that hybrid pitches (sand and water based) would be preferable because of the very high water consumption of water based pitches, it is a pity that a hybrid pitch was not specified for the 2012 Games.
I was surprised at such a high requirement for irrigation. The wildlife meadows on the Park require establishment irrigation for two seasons, (which is not the case in other projects I have been involved with) whilst the trees require irrigation for the first three to four years. Initially, consideration was given to constructing swales to store rainwater but this solution was rejected because “they could not hold the volumes of water required”. So, all irrigation uses water from the Old Ford Water Recycling Treatment Works. There are a lot of green walls around the park which require permanent irrigation, and although drip irrigation is the preferred delivery method throughout the Park for all the planting, using an industry standard approach is a missed opportunity. If the irrigation system was combined with soil moisture sensors then at least the unprecedented rains would have reduced the requirement for watering.
And the result is…
There are no figures to back up the 57% claim, so we will disqualify it. For the 40% target, 18% is estimated to be met by water efficient appliances and the remaining 22% by Old Ford using treated sewage from the northern outflow sewer. Old Ford will provide a minimum 46 Ml (46,000m3) of treated water a year, and as the first direct reuse of waste water in the UK, it will be interesting to see how it performs, particularly in regard to the amount of energy it uses per m3 of water supplied. Water consumption on site during the construction phase seems to have been ignored which (if that is the case) is a cop out. So certainly not a gold medal, but as the feel good factor is still in the air I shall go for bronze.
This article was first published in Green Building magazine, Autumn 2012
 One Mega litre is 1,000,000 litres or 1,000m3
 5,735Ml over 24 years is an average of 239 Ml a year. I assume that the bulk of it will be for the CCHP plant and the 2,818 new homes that will be built on the site, although no details were given in the report.
 The Olympics Village is not classified as being part of the Park.
 Though if the CCHP plant and Eaton Manor hockey park are taken out of the equation, the reduction from water efficient appliances increases to 33%.
by Steven Harris email@example.com
Trumpets! Fanfares! Fireworks? Well, maybe not, but as the Green Deal is softly-softly launched, most of us will probably not notice it starting, despite the energy companies’ best efforts to blame their price rises on it. And maybe it’s right only to whisper the launch since I read recently that when asked, the British public distrust both the words ‘Green’ (sandals) and ‘Deal’ (double glazing salesmen). So is this just an unfortunate choice of words? Well before Green Deal and the current Government there was of course ‘pay as you save’; less untrustworthy words even if they did have a touch of the oxymoron about them.
Back in 2006 at ZEDfactory when we were toying with the ‘invest in energy saving’ concept, it all seemed so much simpler. Take out a loan to put some PV panels on your roof and the monthly saving/income they would generate could help meet your loan repayments, and then as energy prices increased, you might even start making a profit. These were pre FIT days of course. It even seemed to make sense when you looked at insulation. Take out a loan to pay for some additional insulation and the kWhrs you save by having less W/m2/oK escape from your walls would repay the loan with ease.
So what went wrong? – Well lots really!
First though for the positive. PV – fantastic! Point a panel at the sun and it will harvest a pretty guaranteed average annual income for at least the period of a suitable loan. With FIT this of course hit the nirvana of the ‘bleeding obvious’ and those with the nous and free cash got on with it. But herein comes the first problem, namely ‘free cash’. This was picked up in an EST/money saving expert.com web forum in 2010. The point made was, is taking out a loan to invest in PV a good use of your personal credit limit? Yes, it made return on investment sense, but would it mean you couldn’t then take out another loan to replace your car or have that holiday next year?
Similarly, while working with the Ecology Building Society at ZEDfactory back in 2006 we discovered the problem of ‘first charge’. The lovely people at Ecology supported the ‘invest in energy saving’ concept strongly, but being forthrightly prudent as proper mutuals should be, they would only loan the money if they could have first charge on the property. They also liked a safe loan to value ratio, which was considered very strange pre 2008. This was a realisation that you couldn’t just go on borrowing and borrowing using the ‘leverage’ of the projected income. At some point your lever would snap! (Although we did also meet Lehman’s to discuss the idea!). First charge means that the lender is first in line to be paid back if things go wrong and the property repossessed. Even being second in line is risky. And of course, risk equals higher interest rates, equals more work for the energy saving measure to do to pay its way.
At this point things start to fall apart.
The other show stopper, which seems blindingly obvious now, is comfort take up. We naively thought that if you doubled the insulative value of a home, half as much heat would escape from it. Well no! Following EST studies into the effects of cavity wall insulation, it seems instead that the occupants have their home twice as warm, or to put it another way, keep their home warm enough that they don’t have to get dressed under the bed sheets anymore. Great, but bang goes your ‘loan repaying’ savings income stream!
So could ‘Green Deal’ get over all of this and do it right?
Perhaps getting past the ‘first charge’ issue by fixing the loan to the property address (like a gas or electricity bill) rather than property value or occupants credit limit could be a good move, but maybe the idea needs representing. ‘Don’t think about the green deal as a loan repayment, but instead as a utility bill! But this isn’t a bill for the energy you have used, this is a bill for the energy you haven’t! It pays for the stuff that has been done to your home to stop you needing energy. A ‘negawatts’ bill if you like.’ A ‘negawatts’ bill might also, with the correct spin, get over the comfort take up problem. You could now have a choice. Pay for the energy to keep you house warm enough to not have to get dressed under the bed sheets, or pay the negawatts bill to do the same. Hmm. Sounds like Hobson’s choice, but then remember, once upon a time we were concerned with climate change and saving the planet.
However – sadly – for Green Deal, all now lies in the hands of financial institutions and what interest rates they decide to charge. So for the time being I think I might think about the golden rule, but then stick within my credit limit and stay with my traditional, prudent, first charge, cooperative, low cost funder. (It also means I don’t have to keep checking the Green Deal rules).
Lucy Pedler. Director: The Green Register
Since June 2010 we’ve been running our ‘Eco-refurbishment and The Green Deal’ seminar where ‘warts and all’ presentations of residential case studies give delegates in-depth information on how to retrofit their buildings in a sustainable, low carbon way. But one of the frequently asked questions raised in these seminars is ‘what are the risks of interstitial condensation when applying insulation to an existing building?’
As the economy plummets but fuel prices sore, construction professionals are increasingly working on upgrading their clients’ properties rather than new build projects but are very concerned that by adding roof, wall and floor insulation this will move the dewpoint and cause moisture to build up within the fabric of the external envelope. This can cause damp to build up, mould to grow and potentially damage the fabric – or worse still, structure – of the building elements. Alarm bells start to ring and no professional wants to be faced with a possible lawsuit for negligent practice.
Other concerns repeatedly raised in our Eco-refurbishment seminars are ‘Which is the best way of insulating an existing external wall – inside, outside or the bit in between’, ‘How can I achieve airtightness when refurbishing buildings?’ and ‘How can the design team and builders effectively communicate to achieve best practice detailing?’
As always TGR loves to respond to our delegates’ requests for more, unbiased information and we decided to tackle these issues head on by running a series of new ‘All in the Detail – achieving Best Practice Detailing for Eco refurbishments’ seminars around the UK.
Our first seminar was held in London with over 40 delegates attending the whole day. The speakers were chosen firstly because of their in-depth knowledge of eco-retrofit projects and secondly because they were all experienced practitioners and could share some of their practical experiences of building airtight, well insulated refurbishments but with little or no risk of interstitial condensation.
The first – and judging by the delegates’ feedback by far the most well received – speaker was builder Rafael Delimata, director of Bowtie Construction – contractors with a passion for sustainable building. Rafael used a combination of teaching techniques to explain how his company has consistently achieved best practice detailing in retrofits. Using full size construction mock ups of wall and roof junctions he had made especially for the seminar, Rafael illustrated how to achieve very stringent airtightness standards and the challenges of getting continuous, unbroken layers of insulation, vapour checks and breather membranes.
Rafael also used videos to demonstrate examples of difficult detailing such as at roof hips and valleys, dormers, window and door reveals. Architects’ drawings were displayed (anonymously of course!) to show where detailing was tricky and how better communication – both through drawings and between site managers and operatives – would achieve better standards of airtightness and insulation.
The best thing about Rafael’s presentation was that he could prove that his retrofit jobs actually worked using a combination of careful site practices, good communication and a thorough understanding of the technical information on tried and tested building products.
Finally, Rafael addressed the thorny issue of the cost to install low impact building materials, hidden costs like wastage and storage, delays if products need to be reordered and how builders save money compromising on quality or using substitutes.
The next speaker was Mick Morris from Airseal insulation who talked about moisture control in existing buildings and what happens when insulation is added, particularly when it is non-breathable. The risks and dangers of moving the dewpoint and trapping airborne moisture in elements of a retrofit project were also covered.
Next on was Valentina Marincioni, a scientist from NBT who shared some fascinating research she is working on with University of Central London on moisture movement in buildings. Valentina explained that there are three key principles to delivering low energy refurbishment solutions through the building fabric: thermal coherence, air-tightness and moisture control. In order to insure that a fabric solution is delivered correctly NBT have developed a Material System based approach and Valentina outlined the importance of one of these areas, fabric moisture control and the use of moisture modelling software WUFI to assist in the retrofit design process. The research shows that it is a very complicated subject and that the WUFI software systems take into account subtle differences such as location, orientation and even different types of bricks.
Our final speaker was Jean Pierre Wack, director of eight associates who used an extremely interesting case study of a passivhaus standard retrofit house in London to demonstrate quite how far we would have to go to achieve this very stringent standard.
With The Green Deal’s somewhat underwhelming launch on the first of this month (rumour has it that January will see a revamped relaunch) this seminar could not have been more timely as it has helped construction professionals understand the complexities of introducing green measures into existing buildings, something we are going to have to increasing get our heads around as the impacts of climate change on our poorly performing building stock become evident.
Alex Stephenson Director, UK Stormwater Division, Hydro International. www.engineeringnaturesway.co.uk
With one voice, a cry for ‘clarity, clarity, clarity’ has gone out to Government in response to the National SuDS Standards consultation. There are strong indications that both local government and industry believe the standards, as they currently stand, are not yet fit for purpose.
The devil is definitely in the detail as far as the new standards are concerned: The problem is – no-one is quite sure what the detail is. Many are worried that a dilution of the original principles has crept in, introducing exemptions in a number of areas which could undermine the whole intent.
What’s more, just when everyone should be gearing up for an October 2012 start, everything seems to have gone quiet at Defra. No doubt, the responses will have given the Government much food for thought.
So here’s my best guess at the top seven big questions on Defra’s ‘to do’ list.
1. What Will the Guidelines Contain?
The Government has promised detailed Guidelines to accompany the National Standards. There’s little doubt that the Standards in their current form are insufficient without them. As the Local Government Association (LGA) attests, the standards are more ‘a set of guiding principles’ than a ‘national standard or specification’. Many agree the guidelines would need to have been written, scrutinised and agreed by industry before the new SuDS approval system begins. To be effective, the guidance needs to be binding, not just advisory.
2. When will the new regulations commence?
Local Authorities have requested at least 6 months’ notice before commencement. This already takes us beyond October. One leading local authority respondent, the Cambridgeshire Flood Risk Management Partnership claims a 1st October start is “unrealistic” and “unlikely to be achievable” for many councils to build skills and capacity. It seems April 2013 is looking ever more likely – a route favoured by myself.
True, some local authorities are well advanced in their preparations and there is nothing to stop them and forward-looking developers from adhering to SuDs principles in the meantime – providing there is clarity on adoption of any SuDS features developed during the interim phases.
3. What will the Transitional arrangements be?
The Government’s suggestion of a phased implementation in which only developments over 10 dwellings will be required to have SuDS approval for the first 3 years has drawn mixed views. Phasing would allow lessons to be learned on larger schemes by developers and local authorities alike, but some feel this could water down and delay the national take-up of SuDS significantly, as many smaller developers are precisely those that require more guidance and support. One option would be for SABs to be able to sub-contract the necessary expertise from industry, where the skills already exist.
4. What does ‘affordable’ mean?
Affordability is the most hotly debated issue of all: The Government’s statement that “Drainage for surface runoff should be sustainable and affordable to build and maintain” may seem easy to agree with at first glance. But how will affordability be tested in practice?
Developers welcome the addition of an affordability test as part of the guidelines. But there are major disagreements on what affordability means: For developers it means that the cost of constructing SuDS should not outweigh the benefits, protecting them from unnecessary costs. But focusing on capital costs alone is not comparing like with like, and some fear affordability will be used as a ‘get out’ clause. Many argue that affordability should consider the holistic, whole-life benefits of a SuDS scheme. The multi-benefits of SuDs, such as amenity and biodiversity, could also be monetised in some way.
Incidentally, there is a strong argument that SuDS are cheaper or comparable to conventional systems, in any case. And what exactly is meant by conventional, by the way?
5. What does Reasonably Practicable Mean?
The term ‘reasonably practicable’ is used 15 times in the proposed standards. In a dispute between a developer and a SAB – who decides what that means exactly? Will the guidance be sufficient, or will it be left to lawyers to argue?
6. Where does the LA’s responsibility to adopt end, and the Water Company’s begin?
There appear to be some significant potential differences of interpretation of the definition of “sustainable drainage system” as “those parts of a drainage system not vested in a sewerage undertaker”. Respondents have demanded more clarity in terms of which parts of the drainage system will be adopted by the SAB and which part by the Water Company. The forthcoming publication of Sewers for Adoption 7th edition may be able to provide more guidance.
7. Why Exempt Single Properties from SuDS Approval?
The proposal that SuDS Approval and subsequent Local Authority adoption should only be required for drainage systems serving more property is a cause of inconsistency, if not confusion. Why should a large commercial scheme, such as a supermarket for example, not go through the SAB process? What about residential buildings in multiple occupation? Unadopted SuDS on these developments would have to be maintained by the tenants or building owners.
Runoff from large single properties could have significant impact on surface water drainage in the area. What recourse would the water company have in such circumstances? Surely a ruling based on minimum area of land would be more reasonable?
I must stress that there is overwhelming support for the Government in implementing the Flood and Water Management Act, and for the principles embodied in Schedule 3, which seeks to implement the National Standards.
Getting things right from the outset is so important, because failure will lead to a patchy and inconsistent implementation of SuDS across England and Wales. It’s been five years since widespread flooding in England set us on the road to radical changes in surface water management. We must neither falter, nor delay any further.
By Rob Borruso
Having recently wrecked my environmental credentials by having a second child my world is again one of nappies and sleepless nights. Of course we’re told the most sustainable nappy is a reusable one so they’re hanging up everywhere at home, which got me thinking…
Now, I’m not going to use this blog to do a life cycle analysis of nappies but rather to show just how difficult they can be and include things you’d never think of. The case against the disposable nappy revolves around two points; the resources consumed to make them and the space they take up in landfill. The former I’m not going to question but the latter….. I’ve got some issues.
Over 80% of the weight of a used disposable nappy is water which, because the ‘damage’ caused by land-filling domestic waste is still measured quantitatively not qualitatively, appears to be more of a problem than it actually is. I.e. one tonne of water (which is inert) is counted as having the same disposal issues as one tonne of everything else that ends up in wheelie bins. Whereas, from a long term environmental perspective it really isn’t. So the damage caused but putting nappies in a wheelie bin really isn’t the same as putting in plastic coated paper- but is, nevertheless, not desirable.
Especially as there’s an eco alternative, the reusable nappy right? Well maybe. Reusable nappies do consume lots of resources, some obvious, and some not so obvious. Of course there’s the water, energy and chemicals involved in washing the things, but in my opinion these do not outweigh the issues associated with disposables. But then come the less obvious issues, firstly drying (which I’ll return to later) and then there’s washing machine wear. A baby’s worth of reusable nappies will likely generate about 300 additional loads which is pretty close to the scrap life of a modern, (who bothers to get machines repaired?) washing machine. So now in my view we’re pretty close to there being very little difference between disposable and reusable nappies and the argument starts to boil down to which is more precious, landfill space or water and energy.
With the case for reusables now weakened it wouldn’t take much to make the throwaway option better. This is where the huge issues around drying come into play. Nappies are difficult to dry – they absorb a lot of water they wouldn’t work otherwise. Therefore, drying them artificially, either in a tumble dryer (at least 2kg CO2 per load) or over radiators (which consumes just as much energy and can lead to condensation problems) can wipe out their environmental credentials. This is where that most overlooked but massively effective eco-gadget comes into play – the washing line. Even in my west of Scotland home we can get most of our washing ‘out’ on the line. Do architects and especially planners give much thought to this most cost effective energy saving device – no! Much greater effort should be made to encourage their provision and use. I know this is easier said than done. Experiences with communal drying areas (which CfSH does give credit for) that have been less than positive prove that, but really, is designing a washing line facility beyond the skill of humanity?
The point is planning can and should influence behaviour and its behavioural change that is the key to reducing resource consumption not £600m of PV subsidies given to the well off. The system that dictates the houses we should all live in seems, to my mind, to be far too focused on the wrong things; like whether the right shade of grey for the fake slate roof tiles occupies as much time as ensuring dwellings are suitable for a world in which oil is $200 a barrel. The home owners of the future will be much more concerned about their ability to dry clothes (and nappies) or grow some vegetables rather than the exact colour of their brick mortar.