PassivHaus dwellings typically achieve an energy saving of 90% compared to existing housing.
The Code for Sustainable Homes
The Code for Sustainable Homes sets six levels of sustainability for new build housing. Each level includes mandatory requirements for energy performance and water usage, together with tradable requirements for other aspects of sustainability.
In terms of energy, the requirements are a percentage reduction in carbon emissions compared with Building Regulations Part L1 (2006), as follows:
Code level 1 - 10%
Code level 2 - 18%
Code level 3 - 25%
Code level 4 - 44%
Code level 5 - 100%
Code level 6 - Zero carbon
Proposed timeline
Available credits & weightings
CATEGORY |
CREDITS |
% FINAL SCORE |
Energy |
29 |
36.4 |
Water |
6 |
9 |
Materials |
24 |
7.2 |
Surface Water Run-Off |
4 |
2.2 |
Waste |
7 |
6.4 |
Pollution |
4 |
2.8 |
Health and Wellbeing |
12 |
14 |
Management |
9 |
10 |
Ecology |
9 |
12 |
TOTAL |
104 |
100 |
The effect of regulations on the Eco-housing market
Passivhaus Standard
The ECO2H2OUSE is an innovative low-energy house that has been designed to meet the passive house energy standards and levels of air tightness.
The following information relates to the German PassivHaus, from Passivhaus.org.uk
|
PassivHaus Standard |
Compact form and good insulation: |
All components of the exterior shell of a PassivHaus are insulated to achieve a U-Value that does not exceed 0.15 W/m2/K |
Southern orientation and shade considerations: |
Passive use of solar energy is a significant factor in PassivHaus design. |
Energy-efficient window glazing and frames: |
Windows (glazing and frames, combined) should have U-Values not exceeding 0.80 W/m2/K. |
Building envelope air-tightness: |
Air leakage through unsealed joints must be less than 0.6 times the house volume per hour (this is the equivalent of an air permeability value of less than 1 m3/hr/m2 @ 50 Pa). |
Highly efficient heat recovery from exhaust air using an air-to-air heat exchanger: |
Most of the perceptible heat in the exhaust air is transferred to the incoming fresh air (heat recovery rate over 80%). |
Energy-saving household appliances: |
Low energy refrigerators, stoves, freezers, lamps, washers, dryers, etc. are indispensable in a PassivHaus. |
Total energy demand for space heating and cooling |
Less than 15 kWh/m2/yr |
Both in winter and in summer, a PassivHaus will ensure a constant, comfortable temperature without using a traditional heating or air conditioning system.
PassivHaus dwellings typically achieve an energy saving of 90% compared to existing housing.
In January 2008, the European Parliament called on the Commission to propose a binding requirement that all new buildings needing to be heated and/or cooled are constructed to PassivHaus or equivalent non-residential standards from 2011, and a requirement to use passive heating and cooling solutions from 2008.
Cost benefits of building Eco2h2ouse
|
ECO2H2O HOUSE |
COMPETITORS ALTERNATIVE |
TIMBER FRAME |
BRICK & BLOCK |
CODE 4 |
£1,300/m2 |
£1,450/m2 |
£1,425/m2 |
£1,400/m2 |
CODE 5 |
£1,500/m2 |
£1,795/m2 |
£1,750/m2 |
£2,100/m2 |
CODE 6 |
£1,700/m2 |
£1,900/m2 |
£2,100/m2 |
£ ??????? |
Notes:
Tenders were sent out to selected contractors and manufacturers for the same building.
The sample house was a detached 3 bedroomed house with 1.5 bathrooms with brick cladding on exposed south facing slope
Code 4 included solar thermal (40 evacuated tubes) with PCM store and triple glazed windows. Wall/floor/roof U= 0.18
Code 5 included 15m2 of solar PV-T panels, PCM store and triple glazed windows and passive house standard doors. Wall/floor/roof U=0.15
Code 6 included 30m2 of solar PV-T panels, PCM store triple glazed windows and passive house standard doors. Wall/floor/roof U=0.15
The sample site was situated in SE England with normal ground conditions but constrained access