Talk:Zero-energy building

NREL Definition

Anyone interested in this topic should consider reading the definitions as viewed by our own National Renewable Energy Laboratory (NREL). http://www.nrel.gov/docs/fy06osti/39833.pdf I found it quite interesting and not entirely intuitive. As an energy engineer working to describe energy consumption in buildings, I don't readily agree with their definitions in quantifying Site and Source ZEBs. It is apparent for there to be an agreed upon definition as we move toward powering down our infrastructure! Hydronics 05:02, 6 August 2007 (UTC)

Solar hot water

Is "Zero energy building" a general term for any building that meets the definition of needing zero net external energy supply, or does it describe a particular design or set of designs?

If it's a general term, then solar hot water deserves a mention. --Singkong2005 04:14, 5 June 2006 (UTC)

Problem with Zero carbon building being redirected to this article

There's a problem with Zero carbon building being redirected to Zero energy building. A zero energy building is different from a zero carbon building in important ways. Whereas the U.S. focus is on energy security (and hence zero energy building), much of the rest of the world is focused on climate change and carbon emissions reduction (and hence zero carbon building). So, the intro to this article currently reads:

A zero energy building (ZEB) or net zero energy building is a term applied to a building with a net energy consumption of zero over a typical year. In other words, the energy provided by on-site renewable energy sources is equal to the energy used.

Whereas a zero carbon article might be introduced with:

A zero carbon building is a term applied to a building with zero net emissions of Carbon Dioxide (CO2) from all energy used in the building's lifetime. In other words, any carbon-based energy consumed to build and use the building is minimised by energy efficient construction and offset by on-site production of carbon-neutral energy (typically 'renewable energy').

There are in fact about four subtly different definitions to do with construction, embodied energy and energy sources (net zero source energy, net site energy, net zero energy cost, and net zero energy emissions) but the point of the above is to illustrate the important difference between zero carbon and zero energy. So how do we go about formally suggesting a split? -Christiaan 19:54, 28 February 2007 (UTC)

You are right - the various definitions were not made clear, and the introduction had a European bias. I've added a new section on the various definitions, and changed the intro to address this.

If you have more information to include on zero carbon buildings, you could add this under the definition or, if you have enough information for a new article, I suggest to add a link to the words zero carbon building in the definitions section, and go ahead and write the article in place of the redirect page.

Gralo 13:33, 1 March 2007 (UTC)

POV

Under "Potential advantages of ZEB" it is listed "increased comfort due to more uniform interior temperatures". Considering this an advantage or comfort seems very POV to me. Not everyone likes a dull uniform climate, so it could be listed under disadvantages as well. For example, bedrooms are often wanted to be cooler than the rest of the building. Also building interior climate reflecting changes in outside climate can be desirable to not completely dissociate oneself from the nature, as seems to be the case in these "machines for living in" of the arrogant modernist ideal. (Often AC is actually used to make buildings colder than normally when it is hot outside, creating a huge temperature gradient causing a "cold sweat".) —Preceding unsigned comment added by 217.112.243.2 (talk) 16:04, 20 October 2007 (UTC)

Overhaul of several sections needed.

The Energy Generation vs Energy Conservation, Energy Generation, and Design and construction sections are disorganized and questionably referenced (or unreferenced) in parts. The ZEB process could be outlined with one section on lowering building energy use and one on energy generation, then with a generation vs conservation section, too, discussing the balance between those two. Or, one section "ZEB Design and Construction" or whatever, would include sections on those two main parts of ZEBs, energy conservation and generation. I'm happy to rework it, but I probably won't provide a full account of ZEBs because I am only familiar with US zero energy homes, especially hot-humid climate energy conservation. Anyway, please provide some thoughts. Muffinon (talk) 05:41, 8 March 2008 (UTC)

Generalized ZEB info

Also, it would be nice to have some info supporting general construction practices for zero-energy buildings. Right now there are some general, unsupported statements in the generation vs conservation section, and many singular references throughout. Info from an organization that has done studies on many ZEBs would be ideal. But maybe I'm asking for the impossible :) Muffinon (talk) 05:41, 8 March 2008 (UTC)

This page needs information on embodied carbon in building

"BedZED zero energy housing in the UK" at the start of the page is misleading. BedZED was a valuable experiment. A great part of this value was the embodied carbon calculations done by one of the project initiators, Bioregional [1]. They say

However, as this report shows, the embodied environmental impacts of BedZED’s construction materials are within the same range as standard UK housing. The total embodied CO2 of BedZED is 675kg/m2, whilst typical volume house builders build to 600-800kg/m2. Despite the increased quantities of construction materials, the procurement of local, low impact materials has reduced the embodied impact of the scheme by 20-30%.

A 100 square metre flat in BedZED has embodied carbon of 67.5 tonnes CO2e. The average UK citizen creates 11 tonnes of Carbon Dioxide (CO2e) a year (according to UK Government figures). New UK targets aim to cut this by 80%. For the sake of argument divide this target equally between categories "consumables", "building", "transport" and "government" and treat them as carbon rations. This gives the ration for building as 500kg per person per year. For two people living in a 100 square metre flat 67.5 tonnes CO2e is 33+ years of their building ration. That's before the flat is heated and all the other necessary buildings (shops, offices schools etc) are considered.

The embodied carbon in buildings is a very big issue and should have a significant place here.

RedParasol (talk) 04:24, 7 September 2009 (UTC)

Construction

I am begining the design phase of a zero energy home for construction to begin in 2011. It will be build in a cold climit. Will add to this page as I research this topic area.Doc James (talk · contribs · email) 18:46, 25 April 2010 (UTC)

Transmission losses

The article gives a figure of 7% but http://upload.wikimedia.org/wikipedia/commons/4/4e/USEnFlow02-quads.gif looks more like 2/3 of electrical energy is lost. Rich Farmbrough, 19:57, 26 July 2010 (UTC).

Why was this Michigan Project Removed?

Michigan

• The Vineyard Project is a Zero Energy Home (ZEH) thanks to the Passive Solar Design, 3.3 Kws of Photovoltaics,Solar Hot Water and Geothermal Heating and Cooling. The home is pre-wired for a future wind turbine and only uses 600kwh of energy per month while a minimum of 20 kWh of electricity per day with many days net-metering backwards. The project also used ICF insulation throughout the entire house and is certified as Platinum under the LEED for Homes certification. —Preceding unsigned comment added by Blittled (talk • contribs) 17:50, 3 August 2010 (UTC)

I removed it because it was an external link to the project site without any corresponding independently written reliable sources. - MrOllie (talk) 18:06, 3 August 2010 (UTC)

Removed again. Blogs are not reliable sources, please read the guideline. - MrOllie (talk) 14:04, 4 August 2010 (UTC)

Net vs. Zero Energy

I am having a problem with the intuitive difference between "net zero energy" and "zero energy," but am not an expert nor do I have the time to research who is doing what with the technical terminology.

Intuitively, it seems to me that a zero-energy home would have no outside inputs, rather than offsetting inputs. For example, a home that uses natural gas for heating & cooking should not be called zero-energy — even if there is enough equivalent excess PV-made energy to make up for it. That makes sense for the terminology "net" but not "zero."

"Off-grid" cannot substitute for what I think of as "zero energy," because the traditional usage of the term "off grid" can include energy input such as delivered propane.

Since talk pages are supposed to include a proposal, I propose, then, that there be a differentiation between "zero energy" and "net zero energy" per above.

SolarBozo (talk) 19:13, 23 September 2010 (UTC)