Anyone seriously interested in green building should bookmark or subscribe to GreenBuildingAdvisor.com's green homes blog. The blog is updated on a regular enough basis with interesting and reasonably in-depth case studies of sustainable building projects, pointing out key lessons from the build and detailing construction methods, energy sources, choice of materials and other key features. The host site itself is a very useful resource too - you can subscribe to RSS feeds here. The latest project featured is a refurbished Texas bungalow that boasts water efficient fixtures, low energy appliances, heat pump technology, low-VOC finishes and adhesives and  spray foam insulation around the building envelope. 

Greenbuildingadvisor.com has published an interesting discussion on whether large houses can be green. Kim Colomo of Built Green Colorado says size doesn't matter. She argues:

Of course there’s the resource argument: simply put, bigger buildings typically use more resources. But that tendency can and should be mitigated, even in large homes. If big was really the issue, there wouldn’t be green rating systems for schools, hospitals, or large office buildings. We’d only allow home-schools — small ones, of course — and small local retail shops. We’d limit office size and frown on large regional hospitals in favor of small local clinics. That would be silly.

When I hear the question, “Can large homes be green?,” I think the questioner is really asking, “Is it right for some people use more resources — live in big homes — when they could live in smaller homes like the rest of us?” That question is not really about green building; it’s more about moral or social equity, and I don’t think the green building movement should dilute its focus by debating the issue. We need to get ALL buildings as far down the continuum as possible, as quickly as possible, rather than dither over the tiny minority of homes that are large.

Unless the market for large homes just up and disappears, they’re going to get built and bought. There might be fewer of them, and they might be smaller, especially in these economic times. And heck, who knows, there might even be a permanent shift occurring right before our eyes. But let’s focus on getting those builders and buyers to move along the continuum, not argue about where the line gets drawn on size.

On the other side of the argument, Martin Horowitz of Sustainable Solutions disagrees: 

Home buyers expect green scoring systems to provide guidance when choosing between green-labeled homes. These expectations are largely unfounded, however, since almost every rating system ignores or inadequately considers a major determinant of a home’s environmental impact — its size...

...Forget “reduce, reuse, and recycle”: in our sacrosanct pursuit of happiness, we will just buy our way green.

This gluttony has led some to build ridiculously large homes. If they contain recycled materials, wood-pellet boilers, triple-glazed windows, and low-flow fixtures, we call them “green.” Never mind that these homes use three or five times the resources of an average-sized home — or more.

These McMansions are only “green” because rating programs don’t properly question their size or occupant-to-space ratios. While some programs do provide credit for smaller homes, few programs credibly and equitably penalize excessive size. To my knowledge, only the Vermont Builds Greener program has a size limit...

...any building materials and most sources of energy are nonrenewable, and all homes damage the environment when built and operated. When homes are eventually demolished, these materials are usually down-cycled rather than truly recycled. Big empty homes need to be furnished and maintained.

Most people expect green rating systems to quantify this damage. Homes with high scores should do less damage to the environment than homes with lower scores. While a green home should gain points for relatively benign materials, durability, energy efficiency, and healthier indoor air, it should also be reasonably sized.

Two US green building websites - Green Building Law and Green Building Law Update - have trudged through the climate bill that's moving through the US congress to tease out what it means for construction standards in the US. Treehugger synopsises their points here. In essence, the bill:

Establishes a national energy efficiency code for both residental and commerical buildings. 

Mandates an immediate 30 per cent reduction in building energy demand for new build, and a 50 per cent reduction in five years. From reading Treehugger's report, it's not clear if this refers to heating energy demand or overall demand.

Increases funding for national Retrofit for Energy and Environmental Performance (REEP) programs, which assist building retrofits designed to improve energy and water efficiency.

TreeHugger believes some of the measures will face considerable opposition: 

There is a reason that building and planning codes are local: the real estate industry is the biggest financial contributor to the election campaigns of local politicians, and the builders get what they want in the regulations. Federalizing the code will be fought tooth and nail by local and state politicians who will see it as a direct attack on their biggest source of income. At the local and state level they are concerned about Bob the Builder making houses and keeping Larry the Lumber Guy selling 2x4s, not about global climate change. But climate change is a global and national issue, and has to be dealt with at that level.

Democrats in the US Congress are expected to pass Barack Obama's climate change bill tomorrow. The bill aims to cut US emissions to 17 per cent below their 2005 level by 2020, with an 80 per cent reduction targeted for 2050. 

Writing in the Guardian, George Monbiot pointed out some serious flaws in the bill: 

The cut proposed by 2020 is just 17%, which means that most of the reduction will take place towards the end of the period. What this means is much greater cumulative emissions, which is the only measure that counts. Worse still, it is riddled with so many loopholes and concessions that the bill's measures might not offset the emissions from the paper it's printed on...

There are mind-boggling concessions to the biofuels industry, including a promise not to investigate its wider environmental impacts. There's a provision to allow industry to use 2bn tonnes of carbon offsets a year, which include highly unstable carbon sinks like crop residues left in the soil (another concession won by the powerful farm lobby). These offsets are so generous that if all of them are used, US industry will have to make no carbon cuts at all until 2026.

While environmentalists acknowledge the flaws in the bill, many say that it must be passed to provide a stepping stone for stricter cuts in future. Mobiot seems to agree: 

Even so, I would like to see the bill passed, as it at least provides a framework for future improvements. But why do we expect so little from the US? Why do we treat the world's most powerful and innovative nation as if it were a failed state, rejoicing at even the faintest suggestion of common sense?

 

Writing in the Irish Times today, science editor Dick Ahlstrom says:

 A much-trumpeted plan for limitless supplies of free energy has been dashed by the revelation that something cannot be produced from nothing.

An Irish company had promised it could deliver non-polluting, virtually cost-free power but an international jury said yesterday it did not work.

However the verdict has not deterred the company, Steorn Ltd, from continuing to develop a magnetism-based technology it calls “Orbo”. “It is a disappointment, but we had seen this coming for quite a while,” chief executive Seán McCarthy said yesterday.

Steorn took out an ad in the Economist a few years back looking to recruit an international team of scientists to review their device. But the panel has now announced that it is to disband, stating on its website: 

“The unanimous verdict of the jury is that Steorn’s attempts to demonstrate the claim have not shown the production of energy,” it stated. “The jury is therefore ceasing work.”

Steorn, which employs 22 people, remains undeterred - the company is inviting 300 engineering companies to sign a developer licence agreement giving them access to the technology. 

David MacKay - author of the influential book Sustainable Energy: Without Hot Air - proposes a smart idea in the Guardian today: that a gadget should only really be discussed if it can lead to energy savings of 1 per cent or greater.

MacKay suggests this in discussing 'kinetic energy plates' in a supermarket car park, designed to capture energy as cars pass over them. MacKay writes: 

Let's guess that the kinetic road plates extract one fifth of the kinetic energy of the arriving car. For a car weighing one tonne travelling at 20mph when it hits the road plates, the extracted energy comes to 0.002 kilowatt-hours (kWh). Now, the energy used by the car, assuming it is driven three miles to and three miles from the supermarket with a fuel efficiency of 33 miles per gallon, is about 8 kWh. The savings from parking at the green car park thus amount to one four-thousandth of the energy used by the trip to the supermarket.

That's much less than 1%. So this "green energy system" is just eco-bling, creating a delusion of happy progress while distracting people from serious change.

 

The humble electric immersion could play a key role in fighting climate change, according to Dr Mark Barrett, a rearcher at the Energy Institute at University College London.

According to the Guardian: 

Dr Barrett says the heaters could be switched on and off rapidly to compensate for the erratic output of wind turbines and solar panels, each heater controlled by a gadget that responds to signals sent through the electricity grid – a system used since the second world war. "Everybody is always looking for a shiny new silver-bullet solution" says Dr Barrett, "but this idea is cheap, safe, and based on technology that's been around for decades"....

...Dr Barrett explains that 19m domestic tanks, each fitted with a standard 3kW (kilowatt) immersion heater, would provide over 55GW of potentially flexible demand, which could be adjusted to suit the output of renewable generators. The immersion controller would ensure the water temperature stays above a set minimum – so the house would never be without a hot shower – but within a range of 45C-65C the grid would be in control. Along with hot-water storage in commercial buildings, this would provide balancing capacity greater than peak consumption today, and is a key feature of the computer model Dr Barrett has devised to investigate how Britain could best achieve a high proportion of renewable power.

  Check out the Guardian's interactive guide to greening your home. 

Writing on TreeHugger, Lloyd Alter takes a look at two supposedly carbon neutral buildings. The first is the Satander building in Milan, which architects Mario Cucinella have billed as "first zero CO2 office building in Milan."

The Guardian reports that, between 1998 and 2007, green industries in the US were producing new jobs at twice the rate of their traditional counterparts.

Leeds based architects Garnett Netherwood have won an international competition to construct 12-meter high "wildlife towers" along the Leeds and Liverpool canal. The towers will be constructed from parts of demolished buildings.

Speaking in London yesterday, US energy secretary Steven Chu said that painting roofs and pavements white could help to mitigate global warming by reflecting sunlight back into space.

Mario Cucinella architects have produced an interesting theoretical prototype for a low cost sustainable home, dubbed 'Casa 100k'.