What techniques do we use?

Passive House methodology

Certified Passive House ConsultantEric is a Certified Passive House Consultant, and uses the Passive House Planning Package (PHPP) for doing the energy analysis.

It is important to understand that PHPP is useful for any level of retrofit, and is not only used to design to Passive House or EnerPHit (the Passive House certified retrofit standard) levels – it is in fact a flexible tool that is perfect for carrying out an analysis of both an existing building’s energy situation, as well as various levels of improvement. Of course, PHPP can be used to plan an EnerPHit project, but in many cases a less stringent level will have to be sought due to budget considerations.

Passive House (or Passivhaus) is not a brand – rather it is a building construction concept that enables the design of buildings that are energy efficient, comfortable and affordable to run. At its core, Passive House is all about a fabric-first approach, meaning concentrating on improving the thermal properties of the building structure such as the walls, floor and roof while making the building more airtight. This in turn not only makes the building more energy efficient while reducing carbon emissions, but critically it makes the house more comfortable and healthy to live in.

PHPP gives accurate results about a building's energy requirements (Graph credit - Passivhaus Institut)

One major advantage with using PHPP is that it has been proven to give very accurate results about a building’s energy requirements, as shown by this graph, which shows measured results against actual performance.

More details about the Passive House standard is available from the Passivhaus Institut.

Thermal bridge analysis

Thermal bridge detailing in Ladybarn retrofit, following modelling in THERMHeat loss can occur at various junctions (e.g. wall to loft, or window reveals to external wall) with the undesirable effect of creating cold surfaces onto which condensation and mould growth can occur, as well as resulting in heat loss. Thermal bridge modelling therefore enables heat loss and low surface temperatures to be designed out at problem junctions in the proposed retrofit.

Thermal bridge modelling is done using THERM, a software that is used to analyse and quantify heat transfer in building components, as well as to check that internal surface temperatures at the junction remain above dewpoint. Eric is proficient in the use of THERM following training given by the the Association for Environment Conscious Building (AECB).

In 2013, ColdProof helped pioneer modelling protocols specific for retrofit situations with other low energy building professionals in the UK.