Build it, and...

I'm always a tad confused as to what is mandatory and what is advisory when it comes to officail enagegemnt, especially with matters enviro. So I found this interesting: Guidance to help industry respond to the zero carbon challenge

There's no link to the PR, so I'll pop most down here verbatim (sans 'Minster says Yay' puff, which was most of it).

Communities and Local Government published revised guidance to help the construction industry respond to the challenge of meeting the zero carbon homes target.

It responds to comments and feedback from industry, and provides greater clarity in a number of areas including the future eligibility of different energy sources and the method for calculating anticipated water consumption.

HM Treasury will shortly lay draft regulations before Parliament setting out definition of a zero carbon home for stamp duty land tax purposes. An exemption on stamp duty land tax for new zero carbon homes was announced by the then Chancellor Gordon Brown last December.

The Budget 2007 stated: "that from 1 October 2007 all new homes meeting the zero carbon standard costing up to £500,000 will pay no stamp duty, and zero-carbon homes costing in excess of £500,000 will receive a reduction in their stamp duty bill of £15,000. The exemption will be time limited for 5 years until 30 September 2012, but before the end of the time limit the Government will review the effectiveness of the relief and consider the case for an extension".

The key changes are:

* The way energy efficiencies for flats with and without renewables are calculated;
* The way water efficiencies are calculated; and
* The use of off-site renewable energy sources. In future, these will not be eligible unless directly connected to the development concerned. The Code continues to allow connection to gas and electricity grids as long as the home produces net zero carbon emissions over the year.

The Code Technical Guidance, including definition of zero carbon, will be kept under review as new evidence emerges about costs and practicalities, and as technologies develop

Key features of a zero carbon development could include technologies such as:

Combined heat and power
Combined Heat and Power (CHP) is a fuel-efficient energy technology that, unlike conventional forms of power generation, puts to use the by-product heat that is normally wasted to the environment. CHP can increase the overall efficiency of fuel use to more than 75 per cent, compared with around 50 per cent or less from conventional electricity generation.

District heating and cooling systems
District heating is a system for distributing heat generated in a centralized location for residential and/or commercial heating
requirements. District heating systems (DHS) distribute steam or hot water to multiple buildings. The heat can be provided from a variety of sources, including geothermal, CHP plants, waste heat from industry, and purpose-built heating plants.

Aquifer Thermal Energy
Aquifer thermal energy storage uses underground water reserves called aquifers. There are two wells (typically) on either side with hydraulic coupling. One well is for the warm water and the other one is for the cold.
In the winter, warm water is cooled and passed to the cold well. Energy is extracted by a heat exchanger for heating purposes. In summer, the process is reversed and cold water is used for cooling. Once heated, the water is stored in the cold well. The advantage about this system is that it is environmentally safe; the water which circulates from underground to the heat exchangers and back can not be contaminated as it always remains in the system.

Ground Source Heat Pumps
Ground source heat pumps (GSHP) transfer heat from the ground into a building to provide space heating and, in some cases, to pre-heat domestic hot water.

Passive Heating
Passive heating systems are used in buildings which are insulated to a very high standard and make use of solar thermal gain and heat exchanges on ventilation systems, so that no external energy source (other than perhaps background heat generated by people living there and appliances) is required to keep the building warm.

Solar and Wind Energy
Solar energy can be used in a number of ways to provide energy. Passive solar energy is the use of sunlight to keep buildings warm through the direct warming effect of the sun on a building, eg via walls and glazing. Thermal solar panels which provide space heating and hot water. Another method is to convert solar energy to electricity in photovoltaic cells.