How to spot a Passivhaus

As the popularity & scale of Passivhaus grows, unfortunately, the term is open to misuse. To claim the Passivhaus standard a project must meet ALL the rigorous quality assurance requirements. This paper, What it means to claim the Passivhaus standard, explains the technical details & benefits of certification.

Whether you're looking for an off-the-shelf built Passivhaus or building your own, the best way to dodge phoney claims is to aim for certification. If that is not possible, below is a handy quick checklist to ensure you are genuinely getting Passivhaus performance.

 

 

Client checklist

Several quick checks to help you decipher genuine Passivhaus claims:

	Has it been designed in PHPP (PassivHaus Planning Package?) All Passivhaus buildings are modelled in PHPP. The PHPP verification page allows a quick check that the scheme will meet the standard. Require a PHPP model be prepared by a suitably qualified individual from the earliest stage.
	Is the project aiming for certification & who is the independent Passivhaus Certifier? Every Passivhaus project aiming for certification should have a Passivhaus Certifier independent & impartial to the design & delivery team. The certifiers check that all Passivhaus requirements are satisfied & reinforce quality assurance. A growing number of projects in the UK fulfil ALL the Passivhaus criteria but have decided not to undergo the certification process. These self-declared Passivhaus projects differ from PHI Low Energy Buildings (PHI LEB), which have undergone certification but do not meet ALL Passivhaus requirements and fall just shy of the Standard. Learn more about Passivhaus criteria here.
	Is the project designed to Passivhaus Principles? Passivhaus principles are often misunderstood or unclear. Which parts of the Passivhaus critieria have been left out & why? Neglecting core P principles such as using the Passivhaus Planning Package (PHPP) for modelling, ensuring a holistic design approach, and maintaining quality control, can lead to significant performance issues. The Trust's paper explores lessons learned from real-world case studies to describe why Passivhaus principles can be risky business.
	A qualified Passivhaus Designer/ Consultant/Tradesperson is involved in the project. Many schemes have been delivered by those new to the Passivhaus Standard with no formal Passivhaus qualifications or experience. While we advocate for at least one person in the delivery team to have a Passivhaus qualification/ experience, what is more important is the can-do attitude, coupled with high quality & care in construction. Get the right team.
	It has a Passivhaus MVHR (mechanical ventilation with heat recovery) system and MVHR commissioning documents. UK Passivhaus projects require an MVHR system. Certified components offer greater assurance & testing that they will meet required performance & efficiency targets.
	Does it have an airtightness certificate? Is the result below 1 Air Change per Hour (ACH) @n50? A Passivhaus must achieve below 0.6 ACH & EnerPHit below 1.0 ACH at the final airtightness test. Certified Passivhaus projects usually undergo at least one interim test before completing construction - to check the building is on target and rectify any leaks. Learn more in our good practice guide Demystifying Airtightness.
	Does the building display a Passivhaus plaque & certificate from the international Passivhaus Institute? Passivhaus is a global standard. The certified building seals have the international Passivhaus Institute logo and are pictured below. There are slight variations for the different Passivhaus classes. A picture of the certified Passivhaus building plaque is also included.

Downloadable PDF checklist.

 

If one or more of these checkpoints is not satisfied, proceed with caution! Though the project may not satisfy Passivhaus standards, it may still be on track for a low-energy building that exceeds building regulations. Learn more about Passivhaus via the multitude of free Passivhaus resources, including the free interactive introduction to Passivhaus online course.

 

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Further information

What it means to claim the Passivhaus Standard?

Passivhaus Certification

How to build a Passivhaus: Chapter 9 - Certification & Quality Assurance

Get started with your Passivhaus

Passivhaus Benefits Guide

Demystifying Airtightness

Previous PHT story: Consequences of Passivhaus false claims - 12 February 2016

Grand Designs: A guide to Passivhaus homes - 18 November 2021

Passivhaus in plain English: I want a Passivhaus: why bother with certification? - 30 May 2014

WARM: Buying an eco-house

1st January 2023

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Get involved with the UK Passivhaus community

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