This is a Passivhaus Basics blog post that gives an overview of a specific aspect of the Passivhaus Standard.

The international Passivhaus Standard is a clearly defined and rigorous standard for energy efficiency, comfort and quality assurance of buildings. Designing a building to achieve the standard requires detailed knowledge and a rigorous methodical approach to design and documentation. To ensure this happens, it is possible to train and qualify as a Certified Passivhaus Designer or Consultant.

The route to certification is the same for a designer or a consultant. It is only the individual’s prior qualifications and experience that determines if they qualify as one or the other. For clarity, this post will only refer to a Certified Passivhaus Designer, but for all intents and purposes, ‘designer’ is interchangeable with ‘consultant’ in this context.

A Certified Passivhaus Designer, regardless of their prior qualification, works across disciplines on a Passivhaus project. Their role integrates architecture, structure, building services, building science, energy modeling and construction detailing. They will at times both support and challenge the other designers on a Passivhaus Project.

The Certified Passivhaus Designer on a project doesn’t need to be completely independent. They can also be the architect, structural engineer, building services engineer, or another consultant on the team. And the same person fulfilling two roles does have advantages. However, in many cases combining two roles requires more time and work than one individual has available. Regardless, it is best if the Certified Passivhaus Designer is an integral part of the design team rather than just an occasional consultant.

The Passivhaus Building Certifier must be independent of the design team.

A Certified Passivhaus Designer brings the detailed knowledge and rigorous methodical approach needed to design buildings to the international Passivhaus Standard.

043 What is a Passivhaus Designer

Continue reading

Where is all the timber needed to construct more Passivhaus buildings going to come from?

This was a question (paraphrased) asked by a person at a recent presentation I gave about the international Passivhaus Standard. They were clearly under the impression that it was easier / better / necessary to use a timber frame construction system to build to the standard.

I shouldn’t have been surprised since I was presenting on behalf of Architype, where I work. Architype are leaders in designing Passivhaus buildings and timber buildings, so the majority of the Passivhaus buildings I presented were timber construction.

It is a common misconception that timber is best for Passivhaus construction.

Ironically, there is also a misconception that ‘natural materials’ are not suitable for Passivhaus, therefore ruling out the use of timber.

Neither is true!

The international Passivhaus Standard is a performance standard: many different construction systems are possible.

041 Passivhaus Construction Not Just Timber
Continue reading

This is a Passivhaus Basics blog post that gives an overview of a specific aspect of the Passivhaus Standard.

The international Passivhaus Standard does not explicitly require mechanical ventilation. And yet almost every certified Passivhaus building includes a mechanical ventilation system with heat recovery.

What is mechanical ventilation with heat recovery (MVHR) and why is it needed in Passivhaus buildings?

Mechanical ventilation is familiar to most people. This leads to the assumption that a Passivhaus ventilation system is the same as other mechanical ventilation systems. It is not.

There are things that MVHR does not do. It is important to know what these are in order to understand the difference between Passivhaus MVHR and other types of ventilation.

And there are things that Passivhaus MVHR does do that other ventilation systems don’t, including ‘natural ventilation’. It is important to know what MVHR does do, as MVHR is vital to the consistent success of the passivhaus standard.

Mechanical ventilation with heat recovery (MVHR) is key to delivering the benefits the Passivhaus Standard promises – radical energy efficiency and exceptional comfort.

036 What is Mechanical Ventilation with Heat Recovery (MVHR)?
Continue reading

This is a Passivhaus Basics blog post that gives an overview of a specific aspect of the Passivhaus Standard.

The Passivhaus Standard requires airtight construction. What does this mean?

Essentially it means a draught-free building envelope.

A clear airtightness strategy is required to achieve this. The airtight line needs to be continuous even when formed of different materials. And it needs to be joined up, even where there are penetrations.

Sometimes airtight construction gets confused with how a building is ventilated or with ‘breathing construction.’ This post clears up these particular confusions.

And why does the Passivhaus Standard require airtight construction?

Airtight construction is draught-free construction. It is an essential part of the Passivhaus Standard to protect the building envelope, to ensure radical energy efficiency and to provide exceptional comfort.

030 What is Airtight Construction
Continue reading

This is a Passivhaus Basics blog post that gives an overview of a specific aspect of the Passivhaus Standard.

In passivhaus design and construction, there are frequent references to the “building envelope” and the “thermal envelope.” Neither are exclusive to the Passivhaus Standard, but both are important aspects of the standard.

A building envelope is the physical separators between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noise transfer. The three basic elements of a building envelope area weather barrier, air barrier, and thermal barrier. [Wikipedia]

In simple terms, this means that the building envelope is made up of the walls, floors, roofs (or ceilings), windows and doors that separate the inside from the outside. The passivhaus building envelope is also made up of these elements, but there are some key aspects that make the passivhaus building envelope distinct.

The passivhaus building envelope requires a high-performance thermal envelope, it must be continuous and it is key to the fabric first approach.

028 What is the Passivhaus Building Envelope
Continue reading