30 Jun 2007

On Everest Double Glazing

There was an interesting thread over on the selfbuild list last week about someone getting Everest in for a quotation for new glazing.

Had Everest round to quote on windows for our upcoming project. I 
thought they would be expensive, but was in for a shock when he came up 
with £45k for 12 windows, 3 double doors, 2 standard doors and a front 
door with side light! The quote is for UPVC with a lifetime guarantee 
for double glazing, U-value 1.2 and light oak finish. The front door 
is hardwood, all the windows look very good quality and it includes 
fitting. 2 garage doors added another £8600 to the price.

I pointed out that was 1/3 of our budget for the whole house build and 
he seamed to forget all about the sales pitch! I also showed him the 
prices in the self build bible for a similar number of doors and 
windows for £7k, again he was stuck for words.

Before I pushed him out the door he had knocked off 28% for bulk order, 
10% for ordering straight away and after a phonecall to the boss 
another 20% if they can use the house for advertising purposes. 
Knocking off the front and garage doors that we didn’t like much anyway 
left a best price of £20k for 12 windows and 5 doors (inc fitting). I 
was budgeting to get all of them (including oak front door and garage 
doors) for £15k max. Am I in the wrong ball park?

Must say my heart always goes into my mouth when I read that someone is using my book for pricing purposes, especially when there is a huge discrepancy between quoted prices and what I’ve suggested that the going rate actually is. I needn’t have worried. Two replies came back thus:

Your instinct is right. Everest is a very expensive way to go and not really
suited to a new build. As an example, we got 15 assorted (softwood) windows,
with glazing (all double, toughened, Pilkington K and Argo-filled) from
Travis Perkins for £2000. Had to fit the glass into the frames ourselves
which added a few hundred pounds. OK, that was a cheap 'n cheerful answer
(which suits me well enough) but a VERY far cry from - what did you say? -


'get three quotes for anything significant, and six for windows ... 
unless you know what a good price is !

'we paid roughly £10k for six French windows, one very large 
window, one corner window, another window, and two small windows ... 
a few years ago ... toughened & silvered, double glazed, with 
internal glazing bars, fitted ...

Joinery is one of the more complex parts of a build to quote for but what I have been trying to do over the past few years is to reduce the price down to a square metre rate. It’s not perfect because some elements, particularly the smaller pieces, are much more expensive on a metre basis than larger ones. But given that most houses consist of a mix of small windows, large windows and largeish doors, it tends to work out
 reasonably well over a whole house. What people don’t do, of course, which would be very helpful, is to state how much joinery they are buying in square metres. Instead you get long lists — effectively unmeasured joinery schedules — which you can merely hazard a guess at. As a very rough guide, you can guess that the area of joinery is going to be around 20% of your internal floor area, so if you don’t have a joinery schedule to hand, this is a good place to start.

The costs of joinery are also very variable depending partly on the quality but also on how they are finished and fitted. Is the glazing being purchased separately? Is fitting included in the cost? What I found on my last trawl through joinery costs is that prices varied from as little as £80/m2 for unglazed, unpainted softwood frames through to as much as £400/m2 for pre-finished upmarket glazing from the likes of Rationel and Velfac. A basic uPVC system, of the kind that Everest turn out, should be costing no more than £150- £200/m2. My guess is that the house in question has around 40m2 of joinery (not atypical on a selfbuild these days) and that the Everest rep was pitching initially at over £1,000/m2 and ended up down at around £400-£500/m2 mark, still way more than the prices of far better alternatives.

25 Jun 2007

OFT Invesigation into Housebuilding

News that the Office of Fair Trading is launching an investigation into the housebuilding industry had me exclaiming “OK, but why now?” Nothing has really changed that much in the past ten or even twenty years; certainly not the nature of the cozy cartel that exists between the housebuilders, the planners and the amenity groups such as the Council of Preservation for Rural England (CPRE). Both the low rates of new housebuilding and the poor standards of that housebuilding are symptomatic of a general market failure, but then this is no ordinary market.

The OFT obviously wants someone to blame for this state of affairs. Housebuilders point to intransigent planners, planners point at huge landbanks being held back to artificially inflate prices. According to the BBC website, the OFT have appointed an eight-strong team to take representations, but I expect them to get pushed from pillar to post and back, and to end up more or less back where they started.

To my mind, the problem really starts with 1947 Town & Country Planning Act, which effectively nationalised land use. Instead of land being freely brought forward for building by whoever fancied their chances, the new planning authorities started ring-fencing areas suitable for development. As these areas were often large, the small players were effectively cut out from the market. Over the years, this policy of concentration and densification has grown more and more pronounced and the whole development process has been professionalised. The current consolidation going on in the housebuilding industry is merely the latest phase of a process that dates back to 1947.

What the OFT should be looking at is how development took place in the 1920s and 30s, when there were very few controls and no massive national building concerns. There was genuine competition back then and also a high rate of housebuilding. Also they should look closely at what has been happening in Ireland. And France. And Germany. And Scandinavia. And North America. And Australia. They will quickly find out that what goes on in the UK is unique. Other countries build more houses and they generally have far fewer quality issues. Land is often set aside by rural communities for small developers and selfbuilders to create homes and thereby organically grow communities. New development isn’t restricted to all but a few mega-sites, as it is in the UK. Mega-sites may be regarded as sustainable, but they do nothing to enhance competition. The land supply in the UK is now so restricted that the whole process is managed by a small number of very large businesses, who carve up the cake between themselves. The fact that there is little competition is because there is often only one new housing site for miles around.

But rather than blaming everybody or indeed anybody for letting this state of affairs come about, the OFT should come to realise pretty quickly that it’s a creation of our restrictive planning policies. If you really want to reform the housebuilding industry, that is where to start. I don’t think it’ll even be on the agenda.

22 Jun 2007

Bob Matthews on Ventilation

Good series of articles recently on home ventilation in Selfbuild & Design by Bob Matthews, the oldest surviving selfbuild writer in the business. In June, he summarised his findings. In July, he peered into the future. There simply aren’t that many writers out there who would even know where to begin in handling such an assignment. I hope his readers appreciated it.

What did Bob conclude?

• SAP 2005 presumes a ventilation rate of 4 litres/second/occupant, that’s 14.4m3/hr each. I didn’t know that: it seems quite low. For four people living in a 350m3 house, that’s one air change every four hours. Conventionaly, we’ve worked on around one air change every two hours, but I don’t think there is much evidence that this ventilation rate is actually required.

• That 4lts/sec/person requires 100watts of heat to keep at 20°C above outside temps. So for four people, that’s 400 w. And for double the amount of air changes, that would be 800w. Generally, ventilation systems are set up to move much larger amounts of air than this 4lts/sec/person would indicate, so there is a design inefficiency built into most systems.

• Part F of the building regs suggests that you have a 10mm gap undercut on every door, to facilitate air movement around the house. A lot of people won’t like that because it increases noise transfer.

• The default system of home ventilation is trickle vents for supply air extract fans in the wet rooms. Trickle vents must be 5000mm2 in dry rooms (inlets) and 2500mm2 in wet rooms (outlets).

• Passive Stack Ventilation is one of the main alternatives. Trickle vents stay but the extract fans are replaced by air ducts rising from wet rooms to ridge. Kitchen extract requires 125mm tube, utility room, bathroom – 100mm, WC – 80mm or opening window. It doesn’t work in every configuration – bungalows are not tall enough and room-in-the-roof designs have nowhere to run the ducts, and some critics suggest that it only ever works intermittently anyway.

• Assisted Passive Stack is where a fan is added to the system, to ensure it works at all times.

• Central Extract: very similar to assisted passive stack. One fan in the loft pulls air from all the wet rooms. Works with smaller trickle vents than default, and lower extract rates, but designed for continuous operation.

• Positive Input: in many ways the opposite to Central Extract. Instead of drawing air out of the house, it blows it in, putting the house as a whole under a slight positive pressure. The chief exponents of this system are Nuaire. I’ve been rude about Positive Input Ventilation before, but Bob is much more generous.

• Mechanical Ventilation with Heat Recovery (MVHR): discussed in some detail in recent post. Bob reckons that air leakage should be below 4 q50 (don’t ask – it’s a measurement of air leakage under pressure), which is much lower than we are currently achieving on non-manufactured houses. The current building reg standard is 10 q50, whilst the Passivhaus standard calls for 0.6 q50. Quite a difference. MVHR is the only system here that requires both input and output to be balanced, as they are both controlled by the fan or fans. Everything else is either entirely passive (i.e. no fans) or has fan controlled output or input (only one here). This balancing requirement is a crucial and little discussed feature of MVHR. I suspect it needs adjusting quite frequently but is rarely done.

• Individual Room Ventilators with Heat Recovery: rather than whole house solution, you have a individual room ventilators with a heat recovery capability. Designed for continuous operation.

And what did Bob speculate about in the later article?

• He cast doubt the accepted mantra of the current generation of energy wonks: Build Tight, Ventilate Right. Systems like dynamic insulation (see recent post) mean that airtightness may not be quite the holy grail that it is held up to be.

• Intelligent trickle vents, which self-adjust according to wind speed, air pressure and humidity levels.

• Intelligent controls for mechanical ventilation: at the moment, it’s off/on/boost. In the future, systems may begin to emulate the sophistication now seen with space heating controls.

• Supply Air Windows: Howarth are now making these windows which work by drawing air in between the two panes and pre-heating it on its way into the house. In effect, it’s a sort of heat recovery trickle vent, designed to work with the house under negative pressure, so usually installed with passive stack ventilation, or continuous central extract fan.

• Earth tubes: these draw supply air through underground pipes in order to pre-heat or cool the air before it gets to the house. Much experimented with over the years, but nowhere widely adopted. There are fears about contamination and mould growth within the underground tubes and this seems to hold back more widespread adoption of the technique.

• Dynamic Insulation: the capacity of walls and roofs to draw air in through their structure and to pre-heat it on its travels. A topic covered in a recent blog post here.

In fact, supply air windows, earth tubes and dynamic insulation are all ways of passively pre-heating the supply air. All have great potential but they are all also a long way from becoming mainstream.

I particularly like Bob’s concluding remarks. In the future, we will probably reach more understanding about ventilation processes, and we will be able to design systems more accurately. Then there will be less need to over-ventilate in order to be on the safe side, as at present. There is a need for greater knowledge about the complex issues involved in domestic ventilation. A lot more research is required so that we can create healthy environment in our homes while at the same time minimising the damage we do to the environment as a whole.

There are indeed lots of issues still to be resolved:
• Our understanding of house ventilation seems to be being driven by cold climate countries like Canada and Sweden, where ventilation is more critical. Does their take on it really transfer across to our lukewarm, maritime climate?
• Specifically, is airtightness quite as important as we are being led to believe?
• Are fully passive ventilation systems reliable? Or do we require fans to drive at least part of the system?
• Should we be driving towards more sophisticated controls and sensors in order to balance running costs with air quality? Or is dumb good?
• Are the health concerns about drawing supply air through ducting legitimate, or just a fear of the unknown?

20 Jun 2007

The trouble with sedum roofs

The trouble with sedum roofs is that they only get you so far. Eventually, you'll want to break out from under the grass ceiling.

That’s enough of that.

Mechanical Ventilation with Heat Recovery

One of the little discussed details surrounding the Passive House debate is the use and abuse of mechanical ventilation. The Passivhaus standard insists on it: other low energy standards are not so prescriptive. I believe that the way the new Code for Sustainable Homes standards have been drafted, the top levels more or less ape the Passivhaus standard and therefore mechanical ventilation with heat recovery will become de rigeur.

The issue underlying all this is the ever-present contradiction between saving energy and maintaining good indoor air quality. You have to have fresh air inside a home and this fresh air has to be heated (or sometimes cooled) in order for it to remain comfortable indoors. However well you insulate the fabric of the structure, you still have this energy demand to deal with. The energy load naturally varies according to the outside conditions, but it can often be more than 1kW, sometimes even 2kW. That represents around half the overall heat load for the house.

Now the Passive House approach is to first reduce the air leakage of the structure to an absolute minimum. This ensures that you don’t have to heat more air than you actually require. Then you run inlet and outlet ducts around the house and you draw in the fresh air via a heat exchanger, which pulls as much heat as possible out of the exhaust air. This is what is known as a Mechanical Ventilation System with Heat Recovery. The acronym we use in the UK is MVHR.

These air-to-air heat exchangers have been getting more and more efficient over the years and some claim to recapture as much as 90% of the heat from the exhaust air. Also the electric fans that drive them have also been getting more efficient, thus further increasing the CoP (Coefficient of Performance).

Even with a 90% recovery rate, you still need an additional heat source to keep the house warm, but not much. You have reduced the overall heat loss to a minimum. The structure doesn’t transmit much heat, the air leakage is all but eliminated and the supply air is pre-heated by the exhaust air. It’s technically very difficult to do much more than this and this is essentially why the Passivhaus standard is regarded so highly by our energy wonks.

But there are health concerns that have yet to be fully addressed here. Whilst much of the world lives fairly happily with ducted air heating systems, they are not without their problems and issues. And the typical North American home, where this form of heating and air conditioning is the norm, is not built to anything like the airtightness specifications demanded by the Passivhaus standard. What will happen if you a) force people to build to really demanding air tightness levels and then b) force them to use mechanical systems to manage their air supply? We’ve seen a few thousand homes built to these exacting standards in Europe and as yet no one has reported any major problems with air quality. But the UK is proposing to roll out such standards on an unprecedented scale, albeit after 2016. Is this really practicable? Or even sensible?

Take a look at this guidance, emanating from the Canada Mortgage and Housing Corporation recently, on what you need to do to keep your MVHR (which they refer to as HRV) systems tickety-boo. There is a surprisingly long list of maintenance issues to be attended to. Do you really think all UK homeowners will do this? And what will happen if (and when) they don’t?


Your heat recovery ventilator (HRV) can help make your house a clean, healthy living environment, while keeping fuel bills down. But your HRV can't do all this without your help.
It only takes seven simple steps to keep your HRV happy…

The Seven Steps to a Happy HRV

First turn off the HRV and unplug it.

• Step 1: Clean or Replace Air Filters
Dirty or clogged filters can lower ventilation efficiency. Try to clean your filters at least every two months. Filters in most new HRVs can be easily removed, cleaned with a vacuum cleaner, then washed with mild soap and water before being replaced. Older units have replaceable filters. If your HRV is easily accessible, this is a 5 minute job.

• Step 2: Check Outdoor Intake and Exhaust Hoods
Remove leaves, waste paper or other obstructions that may be blocking the outside vents of your HRV. Without this vital airflow, your HRV won't function properly. During winter, clear any snow or frost buildup blocking outside vents.

• Step 3: Inspect the Condensate Drain
Check to see if your HRV has a condensate drain, a pipe or plastic tube coming out of the bottom. If it does, slowly pour about two litres of warm, clean water in the drain inside the HRV to make sure it's flowing freely. If there's a backup, clean the drain.

• Step 4: Clean the Heat Exchange Core
Check your HRV owner's manual for instructions on cleaning the heat exchange core. Vacuuming the core and washing it with soap and water will reduce dust which can build up inside the core.

• Step 5: Clean Grilles and Inspect the Ductwork
Once a year, check the ductwork leading to and from your HRV. Remove and inspect the grilles covering the duct ends, then vacuum inside the ducts. If a more thorough cleaning is required, call your service technician.

• Step 6: Service the Fans
Remove the dirt that has accumulated on the blades by gently brushing them. Most new HRVs are designed to run continuously without lubrication, but older models require a few drops of proper motor lubricating oil in a designated oil intake. Check your manual for complete instructions.

• Step 7: Arrange for Annual Servicing
Your HRV should be serviced annually. If you are not comfortable doing it yourself, contact a technician accredited by the Heating, Refrigerating and Air Conditioning Institute of Canada. Make sure the technician you call has been trained by the manufacturer of your HRV.

Check Your HRV Balance: the Garbage Bag Test
HRVs need to be balanced, with the fresh air flow matching the exhaust flow. If you do not know if the HRV was balanced when installed or if you have changed or added HRV ducts, you may want to check the balance with the following simple procedure. This rough test will take about 10 minutes.

Use a large plastic leaf collection bag, typically 1.2m (48 in.) long. Untwist a wire coat hanger. Tape the wire to the mouth of the bag to keep it open. You now have a garbage bag flow tester. Go outside to where your HRV ducts exit the foundation.

• Step 1:
Crush the bag flat and hold the opening tightly over the exhaust hood. The air flowing out of the hood will inflate the bag. Time the inflation. If the bag inflates in eight seconds or more, go to Step 2. If the bag inflates in less than eight seconds, turn the HRV to a lower speed, and repeat the test. Then go to Step 2.

• Step 2:
Swing the bag to inflate it and hold the opening against the wall around the HRV supply hood. The air going into the HRV will now deflate the bag. Time the deflation. If your HRV is balanced, air going into the HRV will balance the air coming out of the HRV. The inflation and deflation times should be roughly equal. If you find that the bag inflates twice as fast as it deflates, for instance, your HRV is unbalanced. If you can see no problem with the filters that would cause such an imbalance, you should call a service person to test and adjust your HRV.

Please don't ignore your HRV. Just a little bit of your time is all it takes to keep it running smoothly.

• April or May
— Turn dehumidistat (the adjustable control on many HRVs which activates the HRV according to relative humidity) to HIGH setting or to OFF.

• September or October
— Clean core
— Check fans
— Check condensate drain
— Check grilles and ducts in house
— Reset humidistat (40%–80%)

19 Jun 2007

Photovoltaic glass

“When a journalist talks about PV cells, we know we are dealing with an amateur.” Jerry Stokes, President of Suntech Europe, drops this little admonition on me as he talks me over their installation at the Kingspan (Code Level 6) Lighthouse at Offsite 2007 (see previous post). As I have already used PV cells several times in the conversation so far, he has already pencilled me in as a numbskull. I reflect on the number of times I have casually written about PV cells over the years. Oh well, you live and learn. Apparently the photovoltaic cells are the tiny little bits that make up the modules, arrays or panels (all of which are OK to refer to) but on their own are not very useful. You need thousands of cells to make a module. I will know next time.

Suntech is an interesting company. It was started in China in 2001 by Shi Zhengrong, a solar engineer. It’s seen explosive growth, mainly supplying the German photovoltaic boom, and is now listed on the NYSE with a valuation of around $5.5billion. How many six-year-old companies have done that in Britain? (Don’t know, but expect answer to be none). Shi, who owns 40% of the company, is now one of the richest men in mainland China. All from making photovoltaics.

At the Offsite exhibition last week, Suntech were showing off a Japanese PV system called Photovol Glass which is the first translucent photovoltaic skin I have seen. It can be used as a substitute for glass in applications like glazed facades and roofs. As well as generating electricity, it cuts out heat transfer and UV radiation, but admits around 10% of daylight, thus making it suitable for large glazed facades or roof panels. Money wasn’t mentioned in my conversation with Stokes, so I can only assume that it costs rather more than traditional PV, which is hardly well-known for being cheap in the first place, but if it rolls out as Suntech hope, it could pave the way for one day becoming a replacement for standard glass. Or maybe not. What does an amateur like me really know about this stuff?

12 Jun 2007

The Affordability Debate

I have recently been sounding off about house prices. Or the affordability issue, as the great and the good like to refer to it. My contention is that we can no longer build our way out of this problem because a) any new homes will just fill up with migrants from all over the world because everyone wants to come and live and work in the South-East and b) the climate change issue is more important and, until this is solved, it is foolish to embark on large building programmes, however climate-friendly. We should, instead, be concentrating on upgrading what we have already built.

What I have avoided to date is discussing what else could be done about the affordability issue. This is because I haven’t given it a moment’s thought, although somewhere in the back of my mind I am aware that it’s easy for a baby-boomer like me, owning unmortgaged property, to be complacent about it all. On the other hand, our three sons are, or soon will be, at the sharp end of the problem and it would be nice to think that they can house themselves without having to wait for both their parents to drop dead, and then for them to fight over what’s left after the government has had its fill.

There was a fine article about these very issues in yesterday’s Evening Standard by Andrew Gilligan entitled Yes, we can solve our housing shortage. In it, Gilligan suggests that, instead of trying to increase the supply of new homes, it is time now to start dampening the demand. Gilligan started by pointing out that two thirds of new homes built last year in London were sold to investors, a somewhat staggering statistic. He elaborated, and I think I agree with him, that housing has become an investment asset class, decoupled from the normal rules of supply and demand, and that the London market in particular is being driven ever higher by speculation. Those that have property have become wealthy beyond their wildest dreams and now have the wherewithal to purchase second, third and fourth homes, whereas those without property have become locked out, unless they earn top dollar.

Gilligan makes two specific suggestions:

1) that we should insist that the buyers of at least some of our new properties should actually live in them and
2) we should clamp down on tax breaks that buy-to-let landlords now enjoy.

It sounds like a plausible enough platform. But actually I don’t think he has gone far enough. I am struggling to think of buy-to-let tax breaks. I don’t think there are any, unlike the family home, which enjoys the status of a mini-tax haven, thanks to the miracle of Principal Private Residence Relief. And as for insisting that people actually live in the homes they buy, well this is already happening to some extent with the many affordable and shared ownership housing schemes around.

On the other hand, even if the detail is a little wonky, I think Gilligan is onto something. If you made the tax and incentive signals strong enough, I am sure you could dampen down property speculation. It’s not as though demand management has completely gone out of fashion: indeed it’s having a mini revival politically with the introduction of the London Congestion Charge, proposals afoot for nationwide road pricing and tentative discussions about carbon rationing. Why not add housing to the list? It’s a nearly finite commodity, and it’s being allocated according to wealth, not need. Ideal material for vouchers or a rationing system of some description.

But how might it work? Imagine every year each adult would be granted a notional housing footprint, say around 50 sq m each, about the size of a one or two bedroomed flat. If you didn’t own property, you could then sell your housing entitlement: if you wanted to own more than this, you would have to buy it from those who were selling. A market would be established, rather like the carbon trading exchanges, where allowances could be bought and sold. The more distorted the balance between the haves and the have-nots became, the higher the value of the entitlements would be. Such a scheme would aim to greatly reduce the attractiveness of owning property purely as an investment. In effect, it becomes a distributive tax, just as how people envisage carbon rationing as working.

Sure, it would be complex to set up and probably involve about two zillion civil servants to police. It might have all kinds of unanticipated side-effects. Incentive schemes often do. I know, I know. But it’s a start. And it has to have a better chance of succeeding than the total non-policy that the government is currently putting forward.

Has anybody else got any other ideas?

11 Jun 2007

Yvette Cooper at Offsite 2007

Having mumbled my way through more than my fair share of PowerPoint presentations, I am full of admiration for anyone who can talk clearly and coherently without slides or notes for fifteen minutes or more. Housing minister Yvette Cooper, in common with many politicians, can do this. Hats off to her. Furthermore, she projects herself as both business-like and personable, the sort of neighbour who’d be great to have around in a crisis. Run out of milk? No problem, you can borrow a pint from us. Feed the cat for the weekend? We’d be delighted: you know we like your cat almost as much as we like living next to you. Thanks Yvette, you’re a good mate.

But (and it’s a big but) being bright and on the button doesn’t make you right. At her exhibition opening address at Offsite 2007, she expanded on the twin aims of this government’s housing policy, these being to address the issues of affordability and sustainability. This is to be achieved by building more (lots more) sustainable and zero carbon homes, hopefully placing many of them into Eco Towns. This was music to the ears of the audience who comprised, for the most part, building professionals with a greenish tinge.

But (and it’s a big but), at the heart of this policy lies an inherent contradiction. “Yvette,” I wanted to ask, “Yvette, thanks for the milk the other night and all that but I’ve been thinking. How do you tackle carbon emissions by building more houses, even if they are carbon neutral? Where is the roadmap?”

Yvette doesn’t have a roadmap. She has the Barker report on her bedside table for those hot summer nights when the affairs of state get too much and she can’t sleep. Kate Barker has drawn a roadmap to account for affordability, which involves building more homes. Not that it’s a very detailed roadmap: had she taken a peek at what has just happened in Ireland, she might have come to a rather different conclusion. Ireland’s been having a massive housing boom and yet prices have been going up even faster than in the UK. Don’t tell Kate Barker, it might give her indigestion, and, lord knows, she doesn’t need that.

But the other aspiration, to reduce carbon emissions; they hadn’t even thought to ask Kate Barker about those and so she hadn’t put them into her roadmap. So what Yvette and her friends have decided to do is to press ahead with Kate’s ideas but to make all the new houses much much greener.

And that, dear reader, is basically the long and the short of this government’s housing policy.

But it’s still several slices of meat short of the full sandwich. The image kept jumping into my head of a car driver (probably me) attempting to press both the brake and the accelerator simultaneously. That’s what it amounts to. You don’t reduce carbon emissions by building more houses, however green: all this does is slow the rate of growth. And building homes has bugger all affect on affordability either, unless you are happy to wait about 35 years to see any change.

What we have, in effect, is a twin-pronged programme which will neither make houses more affordable nor reduce the emissions of the housing stock. What use is that?

“But what about the existing stock?” asked someone in the audience. “We’ve thought of that,” answered Yvette. But, when it came down to it, it turned out to be a work in progress, something they were paying close attention to and hoped to have some proposals on shortly. I’ve heard that before. It’s always easier to avoid this tricky little issue as it involves forcing people to carry out works to their own homes, which is never a very popular thing to do. Hmm.

How much more fun to get you builders out there to concoct some really novel designs and thereby gently coerce an unwilling population into changing their ways. The image of a few wind turbines spinning around (or not) on rooftops is just so much sexier, don’t you think?

Offsite 2007

Four and a half hours scampering around the BRE car park in Watford today brought on a familiar feeling of having been here before. New housing exhibitions opening, like Offsite 2007, are always accompanied by a feeling of excitement, anticipation, even euphoria, but I come away a little let down and rather bemused. “What was all that about?” I ask myself. It was rather like Offsite 2005 – hardly surprising because it was largely the same people on the same site. But it also reminded me of the Milton Keynes Energy World exhibition in 1986. Twenty years on, what has really changed? On the one hand, you want to congratulate everyone for the phenomenal amount of work undertaken to get everything up and running for the opening event. On the other, you can’t help wondering who this is intended to impress, especially as I understand the public don’t get access to the BRE site.

The star of the show was the Kingspan Lighthouse, the first house in the country to achieve Level 6 of the Code for Sustainable Homes – i.e. it’s zero carbon. It was a peculiar looking affair with lots of chestnut siding wrapped around a tall thin three-storey structure. It didn’t really look like a house, but I think that was the point. In fact, none of the new exhibits looked like houses that we would instantly recognise as houses. Tear up the old, bring in the new. You get the message: this is about re-engineering our lives just as much as re-engineering our homes.

The guys in Stewart Milne’s Sigma showhouse seemed just a little miffed. Their house only got to Level 5 and that thanks to three roof-mounted wind turbines which, of course, weren’t even spinning, let alone producing any electricity. “We’d get a six if we built them in a courtyard setting,” explained their minder. It’s all got very competitive, very quickly.

The Hanson Eco-Oast House made the nicest space, making use of one large room upstairs room, lit and ventilated by the huge vaulted roof. It was the only one with any wow factor, the sort of thing to excite the middle classes. Everyone had balconies, lots of balconies and there was timber in every shade and species you could think of.

So well done everyone who has chipped into this event. But is this the roadmap for tomorrow’s housing? We’ll have to wait and see.

8 Jun 2007

On the books and off the pace

Propping up the bar of the gym the other night, I had a fascinating chat with a guy I used to build with in the 1980s and who, unlike me, continues to plough that furrow today. Pete runs a small building business, mostly doing upmarket renovations and improvements, plus the occasional new build. We talk maybe five times a year so I have a fair idea of what he’s up to and how he is doing.

The issue of timesheets came up. In particular, the habit of certain of his employees of starting a little late and knocking off a little early. Maybe not by much, say ten or fifteen minutes, but enough when you add it all up to make quite a large impression on overall costs. Some are worse than others, as you might expect, but they all tend to do it a little bit. That, and the extended tea break. And the ever so slightly elongated lunch break. Maybe 30 or even 45 minutes during what is meant to be a 7.5 hour day. It’s getting on for 15% of the working day. Pete was of a mind to try and break this habit and was pondering how best to go about it. “Let’s face it,” he said, “in reality, it’s nothing short of theft.”

Pete reckoned it was the mindset of a tradesman who has been on the books with a biggish builder in the past. It’s what they have all learned to do. A sort of 1950s, I’m Alright Jack outlook on life which says that you basically resent selling your labour to another and that you will therefore do as little as possible during the time that you are selling your labour. “It doesn’t happen with the price work subbies,” said Pete. “There is a pecking order. The price work subbies, the genuine tradesmen who are working for themselves, work really hard and mostly pretty well. They stay to see a job through and don’t mess around. Next come the false subbies, the guys who are really working for you full time but maintain their subcontract status; they are somewhere in the middle in terms of effort. And at the bottom of the heap are the employees, the ones who have been taken on the books. They just don’t seem to bother all that much and do the barest minimum.”

All the time I have been working in construction, the government and, in particular, the Inland Revenue have striven to get building workers on the books. This is in order to enhance their tax take, as people working on the books pay full national insurance as well as income tax. They also make a rather lame health and safety argument saying that building workers are better protected by being on the books, despite there not being a shred of evidence to support this view.

But what has been widely ignored is the psychological effect of taking a self-employed tradesman and turning him into an employee. There is something ever so slightly noble about being your own man and that little spark is gently extinguished when you remove this status. I saw it happen in the late 90s when the Inland Revenue made an attempt to stamp out bogus self-employment as they called it. Whether you like it or not, an employee is placed in a craven position, at the beck and call of another man, and most builders don’t really take to that too kindly. Rather than maturing into responsible adults who shoulder their bit with pride, they regress into truculent school kids looking for a bit of a skive. It’s just the way it is.

By way of illustration, I mentioned to Pete that I had had a guy working for me on our bathroom job in the spring who had driven something like 40 miles to get to work, who arrived at 7.20am and proceeded to sit in his van outside our house until just after 8, before starting work. I couldn’t believe that someone would bother to arrive at work so early in order just to sit in their van. But he would return to the van for docky break around 10, and again around lunch for a good half hour. And at 4, on the dot, he was off, even if he was half way through a minor job. Needless to say, he was on the books, clockwatching rather than concentrating on the job in hand.

Whilst it may suit the government to have building workers on the books, I am not convinced it suits the builders or their clients. Bear that in mind next time you are hiring.

5 Jun 2007

On Dynamic Insulation

Ever heard of dynamic insulation? It’s an idea that’s been knocking around for a long time, always in the category of academic curiosity, but now at long last someone is coming forward with a marketable product called Energyflo which, they hope, will bring the concept to the masses and, just possibly, sell in great quantities.

So what is it and how does it differ from ordinary insulation? In conventional building models, heat leaks out gradually through the fabric, be it a wall or a roof. Dynamic insulation seeks to capture that leaking heat and feed it back into the building. It does this by making the insulation layer air permeable (by punching loads of holes in it) and then de-pressurising the house so that air is drawn into the house, heating up as it passes through the walls or roof. In theory, if you get it right, you can recapture all the leaking heat and you could produce a wall with a U value of near zero, without having to use more than about 90mm of insulation.

To get it to work, you have to get a fan sucking like hell inside the building to pull the air inside. What happens to the air being sucked through the fan? Well, here it starts to unravel a little because it gets dumped outside. But in fairness, warm air is going to get dumped outside in any event because you need to have some form of ventilation built into the house and you may just be able to get a second bite at that dissipating heat if you plug in a heat recovery unit.

Last Wednesday (May 30), I sat in on a presentation given by Mohammed Imbabi and Andrew Peacock of Environmental Building Partnership, a spin out from Aberdeen University, which is planning to market Energyflo as the basis of a low energy building solution. They reckon that with no airflow at all, the U value of the 95mm expanded polystyrene panels would be around 0.35, but with the airflow working as planned, the U value falls to around zero: i.e. there will be no heat loss at all.

Of course, it’s early days for this product. It’s still undergoing tests, most notably at a CALA homes site in Edinburgh where it’s been installed in the roofspace. There are also plans for it to be used on a big apartment site in Dubai.

I don’t think the presentation met with quite the level of appreciation the backers were hoping for. Many of the questions expressed a surprising level of scepticism. To work as designed, the Energyflo cells have an air filter embedded within them: someone suggested that this would rapidly clog up in Dubai where there are frequent dust storms. And there appeared to be a finite life to the cells as well, which was determined by the site characteristics (i.e. how much pollution) and the thickness of the filter. But if you are building the insulation into the fabric of the structure, how are you meant to replace it?

Perhaps its churlish to be too critical. As a product, it’s only just making its first tentative steps away from the research labs and there is doubtless much to be learned en route. To establish a foothold in the insulation market, it will have to be monitored on a number of different buildings over a lengthy time period, something we in the UK are not good at doing. So I wish them well, but don’t expect to be seeing a whole mass of dynamically insulated buildings tomorrow or in fact anytime soon.

4 Jun 2007

When will CFL's cut the mustard?

Interesting article in June’s Lighting magazine on Compact Fluorescent (CFL) lamps. In summary:

• Invented in 1981 by Philips. The original SL*18 (pictured) weighed over half a kilogram, but its 18W consumption delivered 900 lumens, on a par with a 75W incandescent, and lamp life was an unheard of 5,000 hours.

• The average EU home now contains 24 lamps, but fewer than 30% of these homes own any CFLs.

• The EU seems to be in the process of banning incandescents GLS bulbs, but it’s not yet clear when this will come into effect.

• Minaturisation: size used to be a major problem with CFLs but the development of electronic ballasts has addressed the size issue, although there are still many light fittings which won’t accept CFLs because they are too big.

• Shape: As size has been getting smaller, so we are seeing more and more conventionally lightbulb-shaped CFL bulbs coming onto the market. Megaman and Firefly Lighting (both Chinese) have got ranges of lamps very similar in shape to conventional bulbs but the prize goes to Japan’s Toshiba whose Neoball Z Real is identical in shape, size, profile and output to an ordinary 60W bulb.

• Dimming: This has been another problem for CFLs as the pulsed output of conventional dimmers can damage the electronic ballasts. You can buy specialised CFL dimmers but that is far from ideal. However technology seems to be riding towards a solution. Megaman have been producing DORS technology (DORS stands for Dim OR Switch). First switch gives you 100% output; then flick on and off a second time and the output falls to 66%, then 33% then 5%. It’s not quite dimming as we have grown to know it but it’s a fair approximation. But this June, Korean firm Feelux launches a smoothly dimmable CFL lamp into the UK, which works with conventional dimmer switches. Look out for their DimPac range.

• Speed: one of the most frequent complaints about CFLs is that they don’t reach full power for half a minute or more. Not very good for bathrooms or stairwells. However Sylvania’s MiniLynx Fast-Start is designed to address these issues: it comes on in just 0.2 seconds and reaches 80% output in ten seconds. Lamp life is not compromised. Expect more fast start lamps from other manufacturers soon.

• Colour quality: many (most?) consumers complain that CFLs emit a cold light that makes colours appear flat and dull. Whilst colour temperature is now similar to GLS lamps (2700K), the other quality of artificial light, colour render, is still proving problematic, especially on the all-important R9 Red Rendition, which incandescent bulbs excel at and CFLs don’t. But it’s quite possible that this will improve over the coming years.

• Disposal: small amounts of mercury reside in every CFL lamp. No one has ever really bothered about this before but if they are to become much more common, then some procedures are going to have to be put in place for safe disposal of CFL lamps. One to ponder.

Snaplite: energy efficient lighting

Last week, I went to visit Snaplite, a company making downlighters, based just outside Birmingham. It’s an unusual outfit, which has carved a niche for itself by concentrating on quality. Whereas the lighting market generally is awash with incredibly cheap Asian imports, Snaplite have chosen to manufacture their products in the West Midlands and to concentrate on providing well-built housings for the various lamps out there.

The business is based largely around the skills of a guy called Peter Jones (not the tall one on Dragon’s Den) who likes to tinker around with lights in his garage. He hit on the idea of manufacturing fire-rated downlighters and Snaplite became the first company to offer these into the UK market in 1998. To date, they have been pitching themselves largely at professional housebuilders but now they are becoming interested in the selfbuild sector, which is how I came to be interviewing them, having met Anthony Ottway (pictured here with Graham Stevens) at the Homebuilding & Renovating show at the NEC in March, where they had taken stand space.

If you go back a few years, to the 1980s, downlighters were regarded as sophisticated and aspirational. Back then, the ceiling-mounted spotlight was still the thing. People did use downlighters in the home but not that often. That started to change when low-voltage halogen lamps became fashionable. People saw what they did in shops and in restaurants and instantly they wanted that same effect back in the home. An industry was born.

Not that this did our overall energy consumption any favours. Whilst low-voltage halogens are around twice as energy efficient as ordinary tungsten bulbs, you need a shed load of them to flood light a room. Instead of a modest house having perhaps 20 or 25 light central pendant fittings, a fully downlighted equivalent would probably use around 60 or 70, typically four in each small room and as many as ten in the main living areas. That’s an awful lot of lights. Anyone considering planning for energy efficiency would do well to bear that in mind.

But it’s another aspect of building homes which brought Snaplite to prominence and that is the problems associated with making holes in ceilings. In the early days of downlighting, no one gave a toss. It was all regarded as part of the fun of using downlights, just a detail to be undertaken as quickly and cleanly as possible. But holes in ceilings are not good news. Although the devastating effects of fire spread through ceiling holes and socket boxes had been known for some time, the fire regs had always ignored them, preferring to concentrate on testing wall and ceiling assemblies built without penetrations. But holes for downlighters not only increase the risk of fire spread, they also let through noise and condensation, and they are a source of air leakage. Additionally, because downlighters burn hot, you need to leave space in the ceiling recess around each light. That’s a whole catalogue of construction woe.

Rather than ignore these problemos, Snaplite hit on the wheeze of designing them out. It then hit on another wheeze of highlighting these problems to the housebuilding industry: their 1998 launch of the fire-rated downlighter made much of the problems raised by competitor products.

Then came interest from the acoustic wonks. When Part E, the sound regs, were beefed up in 2003, a very similar concern surfaced: holes in ceilings were really bad news for people wanting to acoustically separate flats. A fire rated downlighter turned out to work pretty well as an acoustic downlighter as well; not surprising really, because the issue is pretty much the same. The downlighter has to be re-engineered so that the heat is directed down as opposed to being allowed to dissipate in the ceiling void, and the housing around it has to be made from pressed steel and it has to be reasonably airtight. There is, in effect, an integral fire hood. If you do all that, as Snaplite did, then your fitting is pretty much bound to be fire proof, airtight and acoustically-rated.

So Snaplite has product which is fire rated (Part B), acoustically rated (Part E), doesn’t let condensation through (Part C), and is also airtight (Part L –airtightness requirements came into effect for the first time in 2006). Also because of the design of Snaplite’s downlighters, you could lay insulation across the back of them without having a break in the insulation. Competitor products required you to leave a large 600mm gap around the downlighter because they burned so hot. In an era where insulation was at last beginning to be taken seriously, leaving a hole that big made no sense.

Of course, a Snaplite downlighter wasn’t cheap, especially when compared to stuff flooding in from China, retailing for two or three quid. But for a while no other downlighters even tried to compete in quality, and they carved out a good market with the more scrupulous builders, egged on by both local authority building control and the NHBC who were impressed by Snaplite’s approach.

But these days, the competition is catching up. Snaplite are not the only show in town and wholesalers now stock various types of fire rated and acoustic rated downlighters at prices which undercut UK-made Snaplite’s output. Snaplite point out that the industry is full of sharks and that much of the so-called fire-rated kit on the market is nothing of the sort and that, furthermore, there is really no effective way of policing this situation. Their problem is that, having done all the hard work of establishing that ceiling penetrations are a problem, and engineering a solution, their market may be taken away from them by a bunch of cheapskates.

The solution is of course to innovate still further, to stay one step ahead of the game. To this end, they are courting the selfbuild market in the hope that here is a group of specifiers who may be prepared to pay a little more for quality. With the increasing interest in energy efficiency, many selfbuilders want help in designing a low energy lighting scheme that looks good and provides good quality light. They have launched a compact fluorescent range called Emerald, which is designed for ambient lighting in halls and stairwells, and they have added a range of low energy pendants, wall lights and illuminated mirrors so that they have a more rounded range, the sort of thing which a selfbuilder might think of as a one stop shop. LEDs are beginning to feature in this range as well, although to date mostly as shelf lighting and in strips.

Snaplite have also started offering a design service aimed at selfbuilders wanting both quality and energy efficiency. If you are looking at spending over £3,000 on a lighting scheme, which they argue is not an exorbitant amount for an upmarket house, Snaplite will undertake a design for you for £100, refunding £50 of this if and when an order gets placed. It’s an interesting proposition and one I can see may be attractive to a lot of selfbuilders.