The Code for Sustainable Homes – Useful Sustainability Definitions
In 2006, a code to explain the different levels of sustainability in UK homes was released by the government. Since then, every new home built has had to have a classification on this scale. Here, we hope to explain in detail what it means to reach the higher levels of this scale.
Level 4 (Passivhaus) - A dwelling which meets the Passivhaus standard will include very good levels of insulation with minimal thermal bridges, good utilization of solar and thermal gains, excellent levels of air tightness and can be used as a base to go on to achieve higher code levels. A dwelling is deemed to satisfy the PassivHaus criteria if the total energy demand for heating and cooling is less than 15 kWh/m2 of treated floor area per year. The total primary energy use for all appliances, domestic hot water and space heating and cooling also needs to be less than 120 kWh/m2 of treated floor area per year. For energy requirements of the code PassivHaus will usually meet code level four.
Level 5 - This is where net carbon emissions are 100% less than Part L1A of the building regulations stated in 2006. The CO2 emissions are from the energy used for heating, hot water and lighting, so code level 5 is achieved when CO2 levels are reduced or generated onsite.
Level 6 (Zero Carbon) - This is where net CO2 emissions resulting from all energy use in the dwelling is at zero or better. This includes energy used in the operation of space heating /cooling and hot water systems, ventilation, internal lighting and electrical appliances. It also takes into account contributions from onsite renewable/low carbon installations. A zero carbon home must also have a heat loss parameter of 0.8W/m²K or less, and net zero CO2 emissions from the use of appliances and cooking in the home.
The table below charts the ‘code level’ energy requirements which each standard is likely to achieve. To reach code levels other requirements will need to be met including but not limited to water efficiency, waste recycling and surface water runoff. For more information on code requirements of each code level, get in touch with Greenworks.
| Code level 1 | Code level 2 | Code level 3 | Code level 4 | Code level 5 | Code level 6 |
| 10% less than 2006 building regulations | 18% less than 2006 building regulations | 25% less than 2006 building regulations | 44% less than 2006 building regulations (PassivHaus) | 100% less than 2006 building regulations | Zero Carbon |
December 4, 2009 in Green Energy Articles | Permalink | No Comments