OFT Investigation into Bid Rigging

People may be shocked that 112 firms have been accused of bid rigging, but my guess is that the practice is so widespread, that it’s almost universal. It’s certainly just as common down at the smaller end of the building game as it appears to be up amongst the big boys, and I can remember it going on on a casual basis all over the place when I was involved in the jobbing building market.

Here’s what the current edition of the Housebuilder’s Bible currently has to say on the topic:

One practice which is now becoming prevalent is for busy builders to get together and divide up the work in a way (and for a price) that suits them – it’s called covering. It works like this. A job is put out to tender – typically by an architect – to four or five local builders. Some of them are so busy that they simply don’t want to take on any more work. Architects tend to regard refusals to quote rather badly and the builders feel that, rather than risking losing the possibility of quoting for future work, they would like to put in some price, any price. So the next step is to chat with the competition – it’s not hard, it happens naturally anyway – and soon an informal cartel is in place.

Reg: ‘Have you been asked to quote for the old Rectory Job at Chipping Butty?’
Charlie: ‘Yes. I like the look of it.’
Reg: ‘I really can’t see any way we could do that one – could you do us a favour and cover us.’
Charlie: ‘Sure – I’ve no doubt you’ll be able to return the favour soon.’

So Charlie puts in his price and tells Reg to put in a price maybe £20,000 higher. Reg knows he won’t get the job but he hasn’t spent any time or money quoting for it and he hasn’t upset the architect so he’ll stand a chance next time around when he does want the work.

Occasionally the builders know all the other tenderers on any given job – in matters like this the grapevine works extremely efficiently – so that there are cases where every builder on the tendering list has been in on the scam. They all know who is providing the lowest quote and, consequently, the lowest quote is in reality quite a high one. Such a complete stitch-up is perhaps rare but frequently two or three of the quotes will be for show purposes only.

Partly this problem stems from the way building work is procured in the first place. And in particular the practice of builders quoting for free causes a lot of problems. It sounds too good to be true and of course it is. It takes a good deal of time to generate an accurate quotation and most builders simply send tender documents off to a quantity surveyor who carries out the work for them (for a scaled fee, depending on the size of the job). Now builders often end up quoting for five or six jobs in order to win one so the overheads of quoting for jobs they don’t get becomes a significant business expense in itself. Anything that helps to ease the load of having to quote for jobs is manna from heaven for builders so you can see the attraction of any informal price fixing arrangements they might concoct.

Planning Alerts.com

Want to know what’s cooking, planning-wise, in your street? Visit Planning Alerts.com, key in your email address and the postcode you are interested in and you will receive email notification of any new applications in your neighbourhood. It’s in beta and not all local councils are yet included but it’s a good idea, and its free. Alerted to this by Geoff Jones.

GD Fever

What are these people watching? It’s a Wednesday night in Cambridge, there is European football on ITV and Sky, but no, they are not watching the footie. The Brit Awards are also on featuring Sharon Osbourne swearing at Vic Reeves, but they aren’t watching that either.

They are all gathered here to watch Grand Designs. Could this be the start of a new trend? The subject of the programme was an extraordinary house being built on a steep hillside in Bath and this particular group was brought together by Baufritz who supplied the above ground parts of the structure in the programme. Being a super efficient German housebuilding operation, they were pretty confident that Kevin McCloud was going to be complimentary and they invited a group of friends, prospective clients and staff along for beer and nibbles.

So were they over the moon? Or sick as a parrot? “Too much of the programme was spent on the groundworks” was a frequently heard observation, along with “Tiffany was magnificent” and “I never knew a staircase could be a thing of such beauty.” And no doubt about this result: England 0 Germany 2.

FIRST PASSIVHAUS IN UK?

I have been lead to believe, and I think Mr Brinkley will confirm, that there are no house in the UK built to the German Passivhaus standard. I think Mr Brinkley was considering building one but I don’t know if he has done it. In any event, I have just come across what I believe to be the first.

It is actually 2 flats, a 1-bedroom and 2-bedroom, built in the inner city of Cardiff, by an Italian lady. The lady is in fact an architect, educated in Munich, so it is perhaps less surprising that she adopted the Passivhaus standard.

The property is a very contemporary looking house, built in the quiet cul-de-sacs of the Roath area of Cardiff. It has a slightly surreal feel being surrounded as it is by Victorian terraces. The 2 properties next door are also modern-looking but in a more traditional way, which helps to soften the impact of the house.

For those that don’t know the Passivhaus standard was established by the Passivhaus Istitut in Darmstadt, Germany is 1996. Since then around 6,000 houses have been built and certified to the standard, across Europe and the USA. What Passivhaus means, in broad terms, is that the building is insulated to a level that allows the sun and other passive heat gains to produce enough energy to heat the home. Passive gain is the heat from daily activity, given off by people, cooking, the shower, making toast, boiling the kettle. Pretty much everything we do produces heat which can be captured and circulated from warmer rooms (bathroom and kitchen) to cooler rooms (lounge and bedroom) by a heat recovery and ventilation system. Passive solar heat always plays a big role in this design of house and, as is typical, this house has a south-facing wall that is entirely glazed. These are triple-glazed sliding doors that give good access to the garden in summer but allow heat to be captured in winter. They have a U-value of less than 1 compared to 1.8 for the best double-glazed windows.

On the day I visited, the outside air temperature was 50C. The temperature inside was a very comfy 190C. This is a little lower than the typical central heated house, indeed my office is at this moment 210C, but feels cooler than the Cardiff house. This is attributed to the walls of the Cardiff house being lined in plywood. The lady who built it said “wood gives off less coolth than stone”. And I believe her. Mine is a stone cottage and the walls are cool to the touch. Her walls felt warm.

This house has a has a number of remarkable features.

1. It has no heating. No boiler, no fireplace, no stove, no fan heater, nothing. And it is warm.
2. It is a timber-frame house built entirely by local labour. It is not a pre-fab manufactured by hyper-efficient German engineers. She used ordinary Welsh builders with no special skills and no special knowledge. In fact these guys were learning on the job, which did lead to a bit of budget and schedule over-run.
3. The house came in at around £1,200 per m². Which may be a bit high for the standard of finish achieved, but is within bounds and would show a profit if she sold it.
4. The house has lots of solar energy on the roof, both thermal which generates around 70% of her hot water, and PV which generates about 50% of her electrical demand (and these are included in the £1,200 per m²)
5. The whole house, every last detail, is recyclable. Further, most of it is reusable, i.e. it has been built in such a way as to be immediately removable, without damage, to be re-used in another house.
6. She has installed rainwater harvesting to reduce her water consumption from the mains to less than half the normal.


A house that needs no heating needs a lot of insulation. This house has 380mm in the walls, 200mm under the floor and 430mm in the roof. This insulation is all hemp, which has low embodied energy and ever sequesters CO2. This compares to the normal UK standard of 90mm in the walls, 75mm under the floor and 270mm in the roof. In also needs a very high level of air-tightness to prevent heat losses from air movement, and that is where the contractors encountered most of their problems. They were just not used to building to these levels of precision and had to re-do a fair bit of the work.

The point of all this is that it can be done. What this lady has proved is that a self-builder can build a highly efficient house, with trivial running costs (she estimates her annual energy bill at less than £200) without recourse to specialist materials or suppliers. Under the Code for Sustainable Homes the house would easily reach level 4 and maybe level 5.

What she has shown is that all the bleating from the house building industry that zero carbon is unachievable is nonsense. If the process that this lady has pioneered were taken up by the big companies it could be lifted to level 6 and zero carbon emissions without too much trouble. And bring in affordable, sustainable and profitable houses. Is it not time that the house building industry stopped whinging and got on with building the houses we need?

Climbing on a Sustainable Bandwagon

I have just had the rare privilege of attending an RIBA accredited seminar on “Innovation in Natural Ventilation”. For a sustainable building guy like me that is hot stuff. In these days of passive houses, ultra high insulation and ultra low air movement, Innovation in Natural Ventilation is just what I need.

So I duly pitch-up to the local college, full of anticipation for a couple of hours deeply immersed in thermal stacks, heat plumes, low pressure zones, thermal atria and natural convection. What did we get – a bloke selling windows.

A very nice bloke, who knows a lot about windows, but then there is only so much you can know about windows. He did tell us about a new window – parallel opening rather than top, bottom or side hung. Which was interesting for about 15 seconds but struggled to fill a 2 hours seminar.

The bloke’s sole claim for the sustainability of his windows was that opening a window means putting less cooling into the property. Which even he agreed was a bit thin in terms of sustainability credentials. These are, after all, glass panes in an aluminium and stainless steel frame. None or which are particularly sustainable.

By the end of the seminar the issue that was really making me cross was the title of the seminar. It had only one word of truth in it. There was no innovation (parallel opening windows might be an interesting spin but we have had sliding sashes for quite some time) and nothing natural. True, windows provide ventilation but that hardly warrants a 2 hour RIBA accredited seminar.

This was, in truth, another example of the double glazing industry finding a new way of selling an old product.

My view is that sustainability is a serious issue. Maybe I am bound to say that, but why wouldn’t I? I make a living from untangling the conflicting and often misleading information provided by companies purporting to offer a sustainable product. The Windsave wind turbine is a case in point. At £1,200 for your own micro-generation plant it looked like a good idea. The fact that it fundamentally does not work in the way the manufacturer’s suggest caused all sorts of people all sorts of problems, but didn’t seem to worry the manufacturers too much. Or the DTI who spent so much in grants for this one machine that it brought the whole grant scheme for all renewable energy technology crashing down.

Sustainability is said to be “meeting the needs of the current generation without impacting on the ability of future generations to meet their own needs”. If the domestic housing industry is going to change to meet this challenge it has to be on the back of good information, with products that are truly innovative and that really are sustainable.

Maybe it is time for labelling! The BRE produce a guide to sustainable specification and RIBA have accredited this course. Maybe it is time for a star rating system for sustainable products so that the consumer (and the professional specifier) know what the real credentials of any product are. My guess is that the windows I saw today would struggle to get a single star, while wooden sliding sashes would be up at a 4 star rating.

Are these no heat homes?

“We are building homes with no heating systems already.” That was the bold claim made to me by Andy Porter of SIPS@CLAYS at the Harrogate Homebuilding & Renovating show back in November.

“Well, if you are, I’d like to see one,” I replied.

And so it came to pass that on Wednesday of last week, I met up with Andy and he took me to see two of their newly completed homes, one near Beverley in Yorkshire and the other in Accrington, Lancs, both of them what I would call classic selfbuilds.

Both homes had been constructed with Kingspan Tek SIPS panels, 142mm thick, with a U value of 0.2. This is hardly surprising as this is the construction system that SIPS@CLAYS specialise in — they were one of the original Kingspan Tek project partners. One of the houses was double glazed, the other used imported Swedish triple glazing, and both had been fitted with mechanical ventilation with heat recovery (MVHR). Neither house had anything in the way of conventional space heating, but both had wood burning stoves and both had solar thermal panels on the roof.

And what were they like to live in? Had they been cold during our recent cold snaps? Were the residents togged up with woolly hats and scarves, regretting their decision to be so bold as to do away with space heating?

Joan Barker, the builder of the house near Beverley, was still in the process of finishing off the house. She and her husband had moved in about a week before my visit (when it was really cold) and she said that it had been a little chilly for the first two days right after the move, and she admitted to using a couple of 2kW convector heaters to get up to comfort. But since then, no extra heating at all: and the wood burner was only being lit in the evenings. I would have said that she was already one happy bunny, and felt vindicated by her decision to do away with radiators and/or underfloor heating.

In Accrington, David and Jane Hartley had been living in their home since the summer and had had longer to figure out how it was responding. They kept their multifuel Dunsley stove going throughout the winter months (using coal only at night to keep it going) and the MVHR system distributed the heat around the house quite effectively. The room temperatures varied between 14°C and 18°C — not warm by current central heating standards but they found it quite comfortable. Although the stove is located in the middle of the large central living area downstairs, they tended to spend much of their evenings in an upstairs lounge and they noticed that the temperatures were more even upstairs than downstairs, where two of the peripheral rooms were noticeably cooler than the main living area where the stove is. This may be an effect of the uneven distribution of heat via the MVHR ducting.

So have they done it? Are these no heat homes, or are they merely modern variations of houses that might have been built in Beverley and Accrington 100 years ago, heated by solid fuel fires? Are we simply using modern technology (fans and ducting) to shift heat around a house more effectively? These are all interesting questions which I am not sure I can provide a coherent answer to just yet. But in the absence of any genuine Passive Houses in the UK thus far, these SIPs homes stand out as being as close to the new paradigm as we are likely to get in the next few years (being super insulated, pretty airtight, and mechanically ventilated) and they do look to be providing comfortable living conditions with a minimal energy input, which is after all what this low energy thing is all about. I guess the success or failure of these schemes should ultimately be assessed by the size of their fuel bills and in neither instance had they been in occupation long enough to make a judgement on this.

Thermal stores: Witherspoon's vision

The thermal store has been knocking around for a long time (at least since the 1980s) and in truth it’s had rather a chequered history. The concept is simple: it’s a hot water battery. You use it like a bank account — in fact, some people prefer the term heat bank to thermal store: you add heat from whatever source you choose, and you withdraw heat from it for your space heating and domestic hot water, indirectly via heat exchangers. As water is capable of storing around five times more heat than concrete or any other solid building material, many designers have got very excited about the possibilities for thermal water storage.

Over the years, the performance of thermal stores has struggled to live up to the hopes, and many of the early examples ended up being energy drains. Space heating and, in particular, domestic hot water require relatively high water temperatures and the fact that the thermal store has to deliver them indirectly, via heat exchange coils, meant that the water in the tank had to reach 80°C in order to deliver an acceptable output and this factor more than cancelled out any potential energy savings.

However, there is one man in Britain who has been busily beavering away on the design of thermal stores for years and he thinks he has overcome most, if not all, the problems relating to thermal stores. That man is Brent Witherspoon, pictured here with one of his prototypes, his company is Chelmer Heating. He has built up a successful business supplying whole house heating systems based around his thermal store designs and he is about to launch another thermal store, known as the EcoCat.

I went to see Brent just before the Xmas break and he spent two hours telling me all about the EcoCat and the thinking behind it. Whereas his existing thermal stores are designed to run on Economy 7 or to be hitched up to an oil or gas fired boiler, the EcoCat is aimed at green power sources, specifically heat pumps, solar panels and wood burners. In particular, Brent sees the EcoCat as a solution to a problem heat pumps have in producing domestic hot water: whilst they work efficiently at raising temperatures through 35°C (enough for underfloor heating), they don’t look so clever when asked to do more work. If you want hot water for the tap at 60°C, then you might just as well use an ordinary electric immersion heater, which is what a lot of heat pump designs do (though they tend to keep rather quiet about it). The Eco Cat is designed to get around this by incorporating an unvented hot water cylinder within it. When the sun shines, the solar panels will supply the bulk of the domestic hot water: and when it doesn’t, there is a small electric boiler to boost the temperature up from what the heat pump can sensibly do.

The EcoCat addresses another problem which Brent has identified: the typical output of a heat pump is 40lts per minute, whereas the typical requirement for an underfloor heating system is less than 20lts per minute and, when some of the circuits are shut down, this can fall to just 5lts per minute. This imbalance results in the return temperature of the water in the underfloor heating system being too high for optimal efficiency, which causes the heat pump to turn on and off far too often and thus perform way below the intended efficiency level. Brent’s design sidesteps the problem by asking the heat pump to heat the water in the EcoCat, rather than feeding directly into the underfloor heating system. It’s an interesting feature and it’s one that thus far Brent is having trouble convincing heat pump manufacturers that they actually need!

But the principle of the EcoCat is to take the proposition of the thermal store and refine it to the point where it really does add value. As you might imagine, it’s quite a complex beast and it sells for over £2,000, way more than any conventional water storage medium you might choose as an alternative. On the other hand, it’s cheaper than virtually all the low carbon and renewable technologies you might think of using in a new house and its purpose is primarily to get them to work together in the most efficient manner possible.

Where Brent sees an economic advantage for his system is that you can build a low carbon heating system around it using an air source heat pump rather than the more expensive ground source version. The fact that air source heat pumps are less efficient than ground source is compensated for by the use of solar thermal.

Brent reckons he can install a heating system for a new house for less than £15,000:
Air source heat pump rated at 17kW - £4,500 (he currently uses the Unico system)
Underfloor heating pipe and controls: £4,000
EcoCat Thermal Store: £2,300
Flat plate solar panels: £3,000
Electric boiler: £900 (this is to get DHW up to temperature in the winter).

So what Brent is essentially offering is a whole house heating and hot water system, based around his unique vision of what the thermal store is capable of. He has identified that it is not enough just to sell a thermal store: to get them to sing, you have to design the whole house heating system around it.

HIPS update

Whilst the housing market may be taking a bath, many people (OK… Kirstie Allsports) are tempted to blame the introduction of HIPS which are now required on all new homes in England & Wales. But the price of providing these seems to be falling by the day. There are now apparently 10,000 trained Energy Assessors and they are getting as little as £60 a house for their efforts. Methinks they’d be better off with a window cleaning round. Many estate agents are swallowing the extra costs within their fee structures in any event.

Compared with the huge increases in stamp duty on property purchases, brought in by Chancellor Gordon Brown in his first budget in 1997, the cost of HIPs is nothing but a minor irritant.

Sign of the Times

Welcome to the Property Snake.

Lifetime Homes: the 16 steps

Lifetime Homes, as a concept, has been around since 1991. The idea is to make housing usable by people of all abilities and in all phases of life, including childhood. It’s not just about the disabled!

It was developed by a group of housing experts, drawn together by the Joseph Rowntree Foundation. A few of the ideas were incorporated into Part M of the England & Wales Building Regulations in 1999, but the Lifetime Homes concept as a whole is still only widely used by Housing Associations. The Code for Sustainable Homes awards eco points for building to Lifetime Homes standard and, as it stands, the standard will have to be incorporated into all new homes by 2016. You won’t be able to score the 90% rating required to meet Level 6 of the Code without it.

There are 16 design features which combined make up the Lifetime Homes standard:

• Car parking space should be easily capable of enlargement to attain a width of 3300mm

• The distance from the car parking space to the home should be kept to a minimum and should be level or gently sloping

• The approach to all entrances should be level or gently sloping

• All entrances should be illuminated

• Communal stairs should provide easy access and where levels are reached by lift, the lift should be fully wheelchair accessible

• Doorways and hallways have to be at least 750mm wide, or at least 900mm wide when the approach is head-on

• Dining and living areas should have space for turning a wheelchair and there should be adequate circulation space for wheelchair users

• The living space should be at the level of the entrance

• If homes of two or more storeys, there should be space at entrance level which should be used as a convenient bed space

• The design of the property should incorporate a provision for a future stair lift and a suitably identified space for a through-the-floor lift from the ground to the first floor

• The design of the property should provide for a reasonable route for a potential hoist from a main bedroom to the bathroom

• There should be a WC situated at the entrance level of the property and a drainage provision enabling a shower to be fitted in the future

• Walls in the bathrooms and toilets should be capable of taking adaptations such as handrails

• The bathroom should be designed to incorporate ease of access to essential amenities such as the bath, basin and WC

• Living room windows should begin 800mm from the floor or lower and be easy to open

• Switches, sockets, ventilation and service controls should be situated between 450mm and 1200mm from the floor

Comment
Most of these features can be incorporated into most house designs fairly easily and with minimal additional cost. The ones that are likely to cause problems for designers are:

• The requirement for larger bathrooms, especially the future proofing of the downstairs loo as a potential wet room. In small houses, this is a considerable space eater

• Future-proofing a lift shaft: again this is tricky in small houses

• Wide parking spaces

Ideally, from a Lifetime Homes point of view, we would all be living in generous bungalows. However, this runs completely counter to the prevailing mood in planning which demands that we squeeze as much as possible living space into the available footprint. Indeed, another part of the Code for Sustainable Homes awards points for using the basement and/or the loftspace. It’s not difficult to build a four-storey house that conforms to Lifetime Homes standard, but arguably it goes against the spirit of what Lifetime Homes is all about, which is making the whole house accessible to the physically impaired. Box ticking 1 Common sense 0.

Eco Bollocks Award: Terminal 5

News has reached me of the fantastic efforts BAA have been making to help preserve the environment at Heathrow’s Terminal 5, due to open in March 2008. It’s taken the sustainable approach to building very seriously.

Terminal 5, which is so big that it is actually three terminals, designated 5A, 5B and 5C, will use two separate water systems, one for drinking and the other for toilet flushing and irrigation. Water for the second system will be sourced from an in-house rainwater harvesting system, topped up with a borehole supply. They hope to be able to collect and re-use 85% of the rain falling on the terminal catchment area.

In addition, all the bathrooms will have dual flush toilets, and the taps will have on-off sensors combined with aerated flow. BAA trills that it aims to reduce the demand from the public water supply by up to 70%.

Come on guys, stop trilling. It’s an airport.

Is Hydro the only acceptable sorm of generation

It has happened to me again. I was asked to help a client who wanted to install a solar PV system to generate their own electricity. No urgent need for it other than the clients "want to do their bit for the environment". Once I explained the probable costs involved, shockingly they quickly went off the idea. I suggested either wind or water but these did not meet with too much enthusiasm either. Turns out they are active in a protest group trying to stop a wind farm being built on the hill opposite their front door and having their own wind turbine did not sit too well. They have plenty of wind (which is why they are building the wind farm opposite) and it was possible to see the cogs turning - was it possible to do it and avoid being hung by their mates?

A bit of further investigation dug out that uncle, who owns the farm next door, has "a bit of a stream. Probably too small". A swift survey showed that the stream has the potential to support a 2kw turbine - enough for 3 houses. The clients, their uncle and the guy next door are now looking to club together to put the turbine in, and have free electricity for the next 20 years.

Every time I do a seminar I tell the audience to check their stream, however small it may seem. But they never do. They always think I don't mean them because their stream really is too small. But I do, and it probably isn't.

Foundations: alternative approaches

There’s a new house going up on our road. The groundworkers have just finished the excavations: it’s on a backland plot and there are tree root issues, as there often are on backland plots. The photograph shows the state of play today, ready for a foundation pour on Monday. I was talking to the builder and they’ve been asked to go down 2.4 metres in some places, plus adding slip membranes around the trenches. He reckoned that they would be using around 100m3 of readymix, around 15 truckloads.

That is one hell of a lot of readymix for a single house, although it’s not perhaps that unusual in this day and age. The NHBC in particular is incredibly hot on using shedloads of readymix concrete to overcome ground movement problems. Foundation issues are still the largest cause of claims on NHBC policies and over the years they have become more and more wary of clay ground and, in particular, tree roots. The list of species-which-spell-trouble seems to grow ever longer with every revision of the notorious Chapter 4.2 (Building near trees) of the NHBC standards.

But consider that the house at the front of the plot (on the left of the photo) is also surrounded by trees. It’s been there since the 1880s (at a guess) and I doubt very much that it has anything much in the way of foundations — the Victorians used to just spread out the bricks at the base of the wall to make up footings. And I don’t think it’s been unduly affected by subsidence. Subsidence doesn’t really happen much in our village.

So why are we putting 100m3 of readymix into the ground under this new house? The readymix alone will cost the builder at least £6,000, not to mention muck away costs for around 100m3 of spoil. And at around 300kWh/tonne, making this much concrete will release around 9 tonnes of CO2, coincidentally the same amount as the average Briton produces each year.

Remember, it’s not the weight of the house that is the issue. 300-odd tonnes of house spread out across 50 or 60 linear metres of foundations is no great load. Compared to a 40 tonne lorry being held up by a few tyres, it’s nothing. All that concrete isn’t there to hold the house up but rather to stop it moving around: the reason the foundations go so deep is to get down to ground which doesn’t shift about through the seasons.

As I surveyed the foundation trenches of this house this morning, I couldn’t help thinking of the story of Caroline Barry’s straw bale house which was built off a base of car tyres. OK, it’s maybe a little too ethnic, a little too Glastonbury for your average builder, let alone house buyer, but there’s more than a germ of a good idea here. Rather than striving to get down to bedrock, such a house would be designed to float on the ground, with the base quietly absorbing any ground movement.

Maybe it’s idle fantasy — and feel free to explain just why —but surely there must be a more intelligent way of supporting a house than just pouring more and more concrete into the ground?

Are flourescent lamps efficient

I have been asked a few times lately if it is better to leave fluorescent lights switched on as they use so much energy to start up? And, are fluorescent tubes (and by extension compact fluorescent lamps – low energy lamps)really efficient?

Fluorescent lamps, be they standard strip lights or compact fluorescents, use gas discharge technology and it takes 3 to 15 minutes (depending on the type of lamp) to vapourise the gas, get up to temperature and reach full luminosity. It takes no extra power to do this, just a bit of time. So the argument for leaving lights on relates to time rather than energy. If you are popping in and out of a room all day you probably want to leave it on. Otherwise turn it off. To put it simply a light left on uses more energy than a light turned off.

Fluorescents are more efficient than incandescent lamps by a factor of about 4. To be technical, they produce around 90 lumens per watt compared to about 20 watts for incandescents (these figures vary with the type of lamp but are broadly accurate). It is why incandescents have been banned in Australia and are being phased out here. They give a different quality of light, which is what leads to the idea that they are not as bright and therefore you need more of them. My Grandma said the same when her gas lamps were replaced with nasty electric bulbs, but she got over it.

While we are on the subject, I have also been asked if fluorescents have nasty chemicals and gases in them, and the answer is yes! They have 5mg of mercury in a 40w tube. It is a tiny amount, less than the size of a pin head – but poisonous nonetheless. They also have a phosphor coating to the glass (which is what fluoresces and produces the light) which is not pleasant, but not poisonous. The gas in the tube is usually argon which is inert and harmless.

There are new lamps about to hit the market that use xenon gas – no mercury and no phosphors – which are even more efficient. These will produce over 120 lumens per watt.

Pumping heat

Spent the weekend dispensing bon-mots and advice in Harrogate at the Homebuilding & Renovating show, one of six held throughout the UK each year. This year I have been delivering a short lecture on sustainable homebuilding and it has sparked some interesting questions and comments from the audience. However this Sunday it all got a little fiery when someone asked about the difference between air source and ground source heat pumps and whether either made sense for his building project. Rather like the output from these heat pumps, my response was just a little lukewarm.

What I specifically said was that heat pumps don’t make much sense if mains gas is available but that there should be a reasonable payback against oil. “You are doing well if you get a Coefficient of Performance of more than 3.0,” I said. I have been consistently saying this for some time now and at least one heat pump manufacturer, Kensa, seem happy to agree with me.

But up stands this man in the audience who said that heat pumps could now deliver over 6.0 — i.e. twice as much heat output for the power input. Before I could stop myself, I blurted out “That’s rubbish.” It obviously hit a nerve, because he stood up and started getting shirty with me. “What do I know about it” sort of stuff. I have no idea who he was but can only guess he was working for one of the many heat pump suppliers exhibiting at the show.

This made me go all defensive and I started quoting a couple of studies back at him that showed that heat pumps often don’t deliver what manufacturers claim. If only to prove that I do know something about it, if not exactly ranking at world expert status. This of course made matters worse and our man turns around and walks out of the seminar theatre in an act of brazen defiance.

You could have heard a pin drop. Normally, these events pass by without any rancour at all and everything is sweetness and light from start to finish. Here there was a definite feeling that someone thought I that I was being out of order and should be upbraided.

What I think this shows is that the heat pump market is maturing fast, perhaps a little too fast. By all means consider the merits of using a heat pump, but don’t get sucked in by the hype, and beware claims of extraordinary efficiencies achieved.