Carbon neutral buildings are a sub-category of low-carbon buildings. Carbon neutral buildings are buildings which through a series of processes detailed in this article achieve net-zero GHG

Greenhouse gas

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

 emissions during their lifetime.

Buildings and Climate Change

Buildings alone are responsible for 38% of all human GHG emissions (20% residential, 18% commercial). It is the industrial sector which contributes the most to Climate Change.

But according to the IPCC, it is also the sector which presents the most cost effective opportunities for GHG reductions .

What Are Carbon Neutral Buildings?

Carbon neutral buildings are buildings that are engineered to release no GHG at all or to balance the GHG emissions they produce using GHG trades.

Carbon Neutral Buildings Technology

Buildings release GHG in the atmosphere during:

• Construction (incl. renovation and deconstruction)
• Operation

Construction

GHG emissions associated with buildings construction are mainly coming from:

1. Materials manufacturing (e.g., concrete)
2. Materials transport
3. Demolition wastes transport
4. Demolition wastes treatment

The construction, renovation, and deconstruction of a typical building are on average responsible for the emissions of 1,000-1,500 kgCO2e/m2 (around 500 kgCO2e/m2 for construction only).

Strategies adopted by carbon-neutral buildings to reduce GHG emissions during construction include:

1. Reduce quantity of materials used
2. Select materials with low emissions factors associated (e.g., recycled materials)
3. Select materials suppliers as close as possible from the construction site to reduce transport distances
4. Divert demolition wastes to recycling instead of landfills or incineration

Operation

GHG emissions associated with buildings operation are mainly coming from:

1. Electricity consumption
2. Consumption of fossil fuels on-site for the production of electricity, hot water, heat, etc.
3. On-site waste water treatment
4. On-site solid wastes treatment
5. Industrial processes housed in the buildings

Fossil fuels include for example: natural gas, propane, etc.
Depending on the region where the building is located and the building energy mix, operation emissions can typically vary from 0 to over 100 kgCO2e/m2 per year.

Strategies adopted by carbon-neutral buildings to reduce GHG emissions during operation include:

1. Reduce energy consumption
2. Use 100% renewable energy sources

Renewable energy sources include:

1. Solar
2. Wind
3. Low-impact hydro
4. Biofuels (under certain conditions)
5. Geothermal
6. Wave and tidal

Indirect GHG reductions (GHG Trades)

There are three main sources of indirect GHG reductions available for buildings:

1. Green power
2. Carbon offset
   Carbon offset
   A carbon offset is a reduction in emissions of carbon dioxide or greenhouse gases made in order to compensate for or to offset an emission made elsewhere....
   
   s
3. GHG reductions from the selling to the grid of clean electricity produced on-site

These GHG reductions can be used by buildings Owners to offset the emissions which can not be reduced otherwise.

Note: Buildings emissions should always be reported in GHG inventories prior to and independent of any indirect GHG reductions. GHG emissions trades should be reported separately in a different section of GHG inventories.

For this reason, it is recommended to reduce buildings emissions by adopting the strategies listed in previous paragraphs rather than using GHG emissions trades.

Low-Carbon Buildings Today

Carbon-neutral buildings, as part of “green buildings”, are developing very rapidly. Recent examples include:

• Aldo Leopold Foundation Headquarters, Fairfield (WI)
• Kroon Hall, Yale University’s School of Forestry & Environmental Studies
• Sustainable Energy Technology Center, The University of Nottingham, NingBo (China)

Existing Carbon Neutral Buildings Standards

The Low-Carbon Buildings Standard TM 2010, Construction, Operation, Reporting
‘’A Method for Estimating Buildings Lifetime GHG Emissions and Emissions Reduction Performance’’

See also

low-carbon building

Low-carbon building

Low-carbon buildings are buildings designed and constructed to release very little or no carbon at all during their lifetime.-Buildings and Climate Change:Buildings alone are responsible for 38% of all human GHG emissions...

Low-energy house

Low-energy house

A low-energy house is any type of house that from design, technologies and building products uses less energy, from any source, than a traditional or average contemporary house...

Carbon neutrality
Green building

Green building

Green building refers to a structure and using process that is environmentally responsible and resource-efficient throughout a building's life-cycle: from siting to design, construction, operation, maintenance, renovation, and demolition...

Zero-energy building
Passive house

Passive house

The term passive house refers to the rigorous, voluntary, Passivhaus standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling. A similar standard, MINERGIE-P, is used in...