EnerPHit explainer
I’ve had a number of enquiries recently for EnerPHit Services, but many people will be unaware of what it is. Here’s a quick explainer.
EnerPHit sits in the centre of the Venn diagram between Retrofit and Passivhaus. It is the certification for Passivhaus retrofit (hence the capitalised PH in the name). If you love where you live and don’t want to move to achieve your dream energy efficient home, then EnerPHit could be the route for you. EnerPHit is the gold standard for retrofitting and ensuring long-term comfort, a healthy home and low energy bills.
Like Passivhaus certification, it has strict performance criteria for heating demand per sqm of floor area, low u-values and air tightness. It also uses PHPP (the Passivhaus Planning Package) as the compliance tool using different worksheets to the ‘Classic’ approach.
However, it is a little more lenient and recognised that many design decisions used to optimise energy use - like form and orientation - may be fixed and cannot be improve upon. The air tightness target is 1.0, so lower than the Passivhaus 0.6 but still far in excess of Building Regulations new build requirements.
Passivhaus schemes are required to achieve a space heating demand of less than 15 kWh/m2/a, whereas EnerPHit can achieve less than 25 kWh/m2/a.
EnerPHit also allows a certification route using certified components (windows, MVHR, shading devices, glazing) which can be useful for historic buildings where wholesale external changes are impossible. EnerPHit can be phased to recognise how most people need to stagger work due to the cost and levels of disruption.
Clients have asked me, ‘how does EnerPHit sit alongside PAS 2035?’ - the government’s best practice retrofit standard. As PAS 2035 applies to government funded schemes only at present, it is unlikely to also include an EnerPHit requirement, but the two methodologies are still compatible. One of the two calculation methods for producing Improvement Option Evaluations under PAS2035 is PHPP. They both use the same principle of understanding the existing home’s performance before suggesting cost effective measures in the right order.
With Passivhaus design, the use of tested systems and components is encouraged to aid the evidence-based design. However, with retrofit things are more complicated and being a Passivhaus Designer does not automatically make you suitable for a retrofit project using EnerPHit. Combining a Passivhaus qualification with a L5 diploma in Retrofit Coordination and L3 award in Energy Efficiency in Older and Traditional buildings gives the broadest skillset for retrofit professionals. We have chosen to upskill in this way to give our clients the best possible, practical advice.
EnerPHit Services
If you want to explore EnerPHit for your project, please get in contact.
An initial meeting can establish what options are available for your home.
