20 Dec 2007

Why I don't think Code Level 6 is such a great idea

A thought provoking piece over on Fairsnipe questioning whether the Code for Sustainable Homes goes far enough. Martin’s opinion seems to be based around the fact that Barratt have recently been awarded a contract to develop 200 top Level 6 homes at Hanham Hall in Bristol. “Even failed newspaper baron Eddie Shah is reportedly building low cost homes that meet level 5,” he writes.

His implication being that if an amateur can get to Level 5 at low cost, and a box-basher-outer like Barratt can do Level 6, then the bar has been set too low.

I see a similar reaction to the Code as we did to Egan’s Rethinking Construction - we didn’t need it, we couldn’t do it - it will cost too much and then suddenly with a great coat of whitewash everyone was Egan compliant.

I see where he’s coming from but I think he’s completely wrong on this one. Why? What’s wrong with the Code for Sustainable Homes and, in particular, Code Level 6, the zero carbon house.

1. It demands the use of micro renewables to offset the energy being used. I believe that our future energy needs are going to met by a green grid-based solution. The same logic that brought about the creation of the national grid in the 1930s applies today just as it did then: localized power production is an inefficient use of resources. Micro renewables are expensive and often unsuited to small sites, yet Code Level 6 insists that they are fitted to all new homes after 2016. Far better to build and professionally manage large grid-based renewable power stations.

2. The low-energy side of the Code for Sustainable Homes is based pretty much on the PassivHaus standard. Whilst this is the acknowledged gold standard in the field, it’s not without its critics and no one has yet completed a Passive House in the UK, yet alone lived in one for a few years to find out whether it’s as good as its cracked up to be. Its fans claim that it costs only 5-10% more to build to this standard but I am not convinced about this: in theory, the list of differences may only be marginally more but to build a Passive House with air changes at under 1 q50 (as opposed to the current UK standard of 10 q50) takes a lot of attention to detail. Not “Bodge it up, bush, bush” which is how we build most houses in Britain.

3. Even if we overcame this hurdle, it’s still not clear to me that the PassivHaus standard translates to the UK climate, or our customs. For instance, what is the point of fitting triple glazing inside technically impressive insulated frames (U value 0.8 or under) when over half of us like to sleep in rooms with the window open all year round? I don’t think anyone has thought this through.

4. There is a whole ton of stuff in the Code for Sustainable Homes that has nothing to do with low energy housebuilding. The water restrictions are technically very challenging and will require rainwater harvesting systems to be installed on all new properties. This may be a noble aim in the low rainfall regions of the UK, but what if you are building in the Lake District where they have more water than they know what to do with? Lifetime Homes? Good stuff. Considerate Constructor scheme? Right on. But the crisis facing us is climate change, so what are all these other noble initiatives doing in here, muddying the water?

In summary, I find myself in a strange position. I think the idea of having a road map showing us how we should be building in the future is a great idea and I applaud the DCLG for being bold enough to bring on such a plan – it should have happened years ago. But I just feel that the Code for Sustainable Homes is the wrong plan. It’s all very well it being technically challenging to get to Code Level 6 — it is, despite what Martin seems to think — but the goal has to be rational and workable as well. Getting to the top levels of the Code, as it stands, involves substantial costs for very little benefit: that’s not clever, it’s a waste of precious resources. For every pound spent stretching a house from Code Level 3 to Level 6, you could save twenty times more energy addressing the energy gaps in the existing stock.

Afterthought: I don’t wish to snipe at Barratt for taking on this Code Level 6 project in Bristol. I think it should be built, occupied and monitored for three or four years to see how it works. That would take us to….about 2014. That would be the time to make a final decision about the roadmap.

6 Dec 2007

Should we carbonize interest rates?

This morning, the radio bulletins are full of speculation about interest rates. The Bank of England Monetary Policy Committee (MPC) meets today to decide whether to change the Bank’s base rate from the current 5.75%. With the financial world in a lather about the credit crunch, the betting is that they will cut by 0.25%, though some are so desperate they are hoping for a 0.5% cut.

Yet the MPC’s brief is not to respond to financial crises. It is charged with just one task, which is to keep a lid on inflation, and inflation is currently above its target range so they really should be considering raising rates, not cutting them. It’ll make for a very intriguing meeting. And it also neatly exposes a conundrum at the heart of government policy. Why track only price inflation? And how exactly do you measure inflation anyway?

It seems to me that there is both good inflation and bad inflation. Or to put it another way, not all prices rises are inflationary, as they may simply cause demand to fall. An example of good inflation is oil going up in price: recently it’s been nudging a headline grabbling $100 a barrel. Surely the world is a better place with high oil prices, as it sends a strong signal to us to stop burning quite so much of it, and to start looking for alternative ways of creating energy. So why should we be hit with high interest rates because the oil price is high?

Following on from this, I have been thinking that maybe the MPC’s target should be modified. Carbonized even. Instead of just looking at a theoretical basket of prices (a haphazard undertaking at best), should it not start considering fossil fuel use as well? Or even instead? How would it work?

The target for carbon use would have to be negative, say 3% less each year. Provided the country meets that target, then interest rates would be set breathtakingly low, encouraging zero carbon growth. On the other hand, if the country as a whole fails to meet the target, then the MPC would raise interest rates so as to dampen economic activity, if necessary pushing us into recession (which is reckoned to be the single most effective brake on carbon use yet devised). Stiff medicine maybe. But isn’t that what we need?

4 Dec 2007

Review: Fred Wellings British Housebuilders

It’s not exactly a page turner, nor something you read from cover to cover, but Fred Welling’s history of British Housebuilders in the 20th century has some fascinating insights into this very strange business.

One of the facts to emerge from his study is just how insular housebuilding is a sector of the economy. It has proven very difficult, verging on the impossible, for housebuilders to expand into other related areas, such as contracting or commercial property. And it’s proven just as difficult for other businesses to expand into housebuilding.

Furthermore, there is an almost total lack of overseas activity: only Taylor Woodrow and Wimpey (now merged into one) ever had significant businesses outside the UK. And conversely, there is an almost total absence of foreign takeovers within the quoted UK housebuilding sector.

With land supply being just a little restricted, the only way for housebuilders to expand their business is through acquisition. Yet Wellings looks at the question of the optimum size for a housebuilding operation and concludes that there is very little economic advantage in expansion, as the unit of production is essential a building site and the costs of running many building sites outweigh any savings in admin and overheads. He reckons the optimum size is around 500 units a year, about the amount a single manager is capable of handling.

3 Dec 2007

Barratt's Eco Village

Whilst Yvette Cooper and her chums would have us believe that the drive towards zero-carbon homes will transform the way we design and build houses, the reality is more likely to look something like this photo. This is Barratt’s Eco Village in Chorley near Manchester and it’s probably one of the most depressing photos of the year. For it could be any Barratt estate anywhere in the past twenty years, except that it’s got a few micro wind turbines stuck up above the rooftops. Some future we have to look forward to here.

To be fair, the site has been conceived more as a test bed for zero and low carbon technologies than as an exemplar of what homes might look like. But surely the Barratt design department could have tried just a little bit harder, seeing as they knew it was going to be on view.

An article in the latest Building reports on the results of a year’s survey by the University of Manchester on the performance of five different technologies featured here at the eco-village. The results more or less confirm figures gleaned from other tests.

• Micro Wind Turbines: two different types tried: both useless, producing virtually no power at all

• Ground source heat pumps: three different ones fitted, which the manufacturers claimed would deliver a CoP (measurement of efficiency) of between 3.0 and 5.0. Average CoP achieved? Just 2.6. They work, but not as well as we are led to believe.

• Photovoltaics: three 8m2 arrays placed on three roofs. Output varied depending on orientation and angle. South facing was best (not surprisingly): a 45° one produced 1034kWh of electricity in a year. An east facing one at 60° produced 760kWh whilst another east facing one mounted at 45° produced 818kWh. These results are bang in line with expectations: no one doubts that PV arrays produce power in reasonable quantities, the problem is the cost of installing them.

• Solar thermal: comparisons were made between a 2.5m2 flat plate and a 3m2 evacuated tube, both used to heat a 180lt hot water tank. Both succeeded in doing this for the summer months: the evacuated tube could get the water to 75°C, as compared to 60°C for the flat plate collector. The researcher, Dr Tony Sung, makes an interesting point that this added performance wasn’t of any obvious value, as 60°C is plenty hot enough.

• Micro CHP: two units fitted, both Whispergens. One produced 11,000kWh of heat and 680kWh of electricity, the other 9,600kWh heat and 260kWh of electricity: the difference between them is explained by the different lifestyles of the occupants, but interesting to note that the average power:electricity ratio is 20:1, only half as good as the Carbon Trust survey results.