The term PassivHaus or Passive House refers to a specific construction standard. The standard can be met using a variety of technologies, designs and materials and across Europe PassivHaus is the building standard.

PassivHaus buildings have an excellent indoor comfort climate in both winter and summer without the need for a conventional heating system.

The PassivHaus standard originated from the workings of Dr Wolfgang Feist (a Physicist from the University of Darmstadt in Germany) who provided a theory that buildings do not require conventional heating or air conditioning systems. By ensuring the fabric of the building is airtight / thermally efficient and sourcing energy actively through solar gain and passively (ground, water and air) a building is able to heat and cool itself.

A dwelling built to PassivHaus standard typically comprises:-

1. ‣Very good levels of insulation with minimal thermal bridges;
   

2. ‣Well thought out utilisation of solar and internal gains;
   

3. ‣Excellent level of airtightness;
   

4. ‣Excellent indoor air quality provided by whole house Mechanical Ventilation and Heat Recovery (MVHR) system with highly efficient heat recovery.
   

Dwellings built to PassivHaus standards typically achieve an energy saving of 90% compared to conventional build.

In Europe more than 20,000 dwellings have been built to the PassivHaus standard.

The PassivHaus standard is assessed using the PassivHaus Planning Package (PHPP) under which the following key milestones must be met:-    

1. ‣Insulation – All components of the exterior shell are insulated to achieve a U-value that does not exceed 0.15 W/m2/K.
   

2. ‣
   

3. ‣Southern Orientation and shade requirements – passive use of solar energy is a key component.
   

4. ‣
   

5. ‣Energy efficiency of window glazing and frames – windows (glazing and frames combined) should have U-values not exceeding 0.80W/m2/K.
   

6. ‣
   

7. ‣Building Envelope Air-tightness - air leakage through unsealed joints must be less than 0.6 times the house volume per hour.
   

8. ‣
   

9. ‣Energy saving household appliances – low energy refrigerators, freezers, cookers, washers, dryers etc are vital for PassivHaus compliance.  
   

10. ‣
    

11. ‣A PassivHaus has a total energy demand for space heating and cooling of less than 15kW/m2/yr.
    

PassivHaus standards significantly exceed the current Government annual energy output standards, which are:-

Detached house 40-45 kWhr / m2 / yr+200%

Semi-detached house            35-40 kWhr / m2 / yr+166%

Terrace / apartment block            30-35 kWhr / m2 / yr+133%

PassivHaus standard            15 kWhr/ m2 / yr 0% 

LCC understand that some clients will not necessarily want or be able to achieve PassivHaus standard. Our objective is to work with clients to provide the most energy efficient and economical method of construction. LCC has an ethos and responsibility to provide solutions which reduce the buildings carbon footprint and preserve the environment for future generations.

PassivHaus and the Code for Sustainable Homes

The Code for Sustainable Homes (CSH) is the UK Government legislative process to reduce carbon emissions from homes and buildings. It is a whole house approach and provides architects, builders and developers with a range of options to achieve carbon neutrality by scoring points against a matrix of pre-determined objectives.

CSH is a set of timelines which reduce the amount of carbon emissions in new build homes between 2006 and 2016 and is based upon the emissions target of the Building Regulations 2006 (Part L).

2007 Code level 3 (-25%)

2010 Code level 4 (-44%)

2013 Code level 5 (-100%)

2016 Code level 6 (-100% zero carbon).

In theory CSH is a practical and sensible way in which to achieve a reduction in carbon emissions. However it is a major step change from standard current Building Regulations and required huge investment in re-training and new technologies. In practice CSH is creating confusion and doubt as to its practicality, viability and affordability towards achieving carbon neutrality.

There is no exact “fit” between CSH and PassivHaus and notionally it is believed that PassivHaus sits at approximately Code 5 level. Since the gap in energy reduction levels between code level 4 and 5 is substantial (56%) a well built PassivHaus can achieve a notional code level of 4.5 or approximately 65% below Building Regulations 2006 (Part L).

Within Europe the PassivHaus standard has been adopted by the European Government and will be the European Building Standard by 2015. 

Within the UK there is currently work being undertaken by the Building Research Establishment (BRE) on behalf of the Government to consider aligning CSH with PassivHaus.

WHAT IS A PASSIVHAUS?

Contact: Passivhaus specialist UK

Phone number: +44 844 809 9902

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