Passivhaus Bitesize Training Syllabus

Who are the Bitesize sessions for?

This course is aimed principally at building professionals in the UK: architects, builders, structural and services engineers, quantity surveyors and potential clients – all can learn how to deliver real low energy buildings. It introduces the principles behind the Passivhaus standard and for achieving low energy performance. Unlike the full Passivhaus Designer course and exam, these sessions do not require calculations, but show the principles behind the standard so that every member of the design team can understand what the Passivhaus Designer on the team is doing.

Fundamentals of Passivhaus

This half-day session introduces the principles behind the Passivhaus standard (thermal comfort!) and the differences from normal construction so that everyone on the design team can understand the process. At the pre-planning stage, the focus is mostly on how the choice of massing/shape and glazing/fenestration can make significant differences to how easily the design can meet the Passivhaus target. Post planning permission, particularly at detailed design stage, the emphasis shifts to ensuring that the actual construction is as close to the theoretical thermal performance as possible. In the UK, this gap between theory and practice has become known as the “performance gap”. The main culprits are examined: lack of airtightness and problems with insulation, such as a lack of understanding of thermal bridging and convective bypass, and how these impact negatively on the thermal envelope.

The requirements for all-seasons comfort are also discussed: summer overheating can be dealt with by design if there is an understanding of the processes: seasonal shading, natural and/or mechanical ventilation, together with care over uncontrolled internal heat loads can deal with most problems without recourse to cooling in this climate. Minimizing summer overheating is a core part of the Passivhaus target.
Finally, we take a look at the support and resources available in the UK, from to Passivhaus designers and building certifiers working in the UK.

Construction of Passivhaus

How do I build a Passivhaus? How is it different from normal construction? This half-day session answers these questions, along with some specific guidance on achieving the level of airtightness and thermal bridge-free construction required by the standard.

Airtightness, convective bypass and thermal bridging are discussed in relation to common constructions. Insulation materials are shown and their properties discussed, singling out those that are effective in damp and load bearing situations. Suitable airtightness materials are discussed and shown, and the necessity of an airtightness strategy discussed.

The session stresses the preferred option of designing out thermal bridges rather than using expensive load bearing insulation. Along with avoiding thermal bridging, keeping the airtightness layer simple on plan and site is stressed. You will get a chance to try your hand at detailing some common construction elements in a small group exercise.

Finally, but not least, a look at the contractual side and suggestions for ways responsibility can be allocated to carry the Passivhaus principles through to the on-site teams.

Building Services for Passivhaus

What building services are necessary for a Passivhaus? This half-day session explores the different services required in true low energy buildings. In these buildings, the heat requirement is usually smaller than the other loads such as hot water. One of the reasons for this, other than the fabric first approach, is the adoption of mechanical ventilation with heat recovery (MVHR) systems. These mechanical ventilation systems need to be integrated into the building for successful operation, and we look at the necessary components, how they should best be installed, their space requirements, and where the supply and extract ducts need to be terminated. The maintenance access requirements (for filter changes) are considered. We touch on commissioning and how this needs to be carried out. There is a small group exercise of finding suitable locations and spaces for the equipment on a simple plan, all from the point of view of a non-specialist.

The second part of the session looks at how the choice of fuel for heating and hot water system can be different from conventional buildings: the Passivhaus requirement for heating systems is to produce a continuous trickle of heat, rather than a conventional system switched on and off by a time switch. The design of hot water systems can be improved to minimize losses, using radial plumbing in small diameter pipes, and there is a short group exercise on this. The definition of primary energy is explained and how to pass the Passivhaus requirements for this, in particular the effect of fuel choice and the difficulties communal heating systems can bring.

Putting Passivhaus into Practice (Crit. Session)

This session has been developed due to demand from participants for feedback on their own designs from experienced Passivhaus designers and certifiers. Modelled on the architectural “crit.” session, where designs are presented and discussions follow about the critical design decisions made, this format has turned out to be effective in engaging all of the design team. During this session, a number of schemes will be shown and discussions followed based on achieving Passivhaus certification. If you would like your design to be included, you will need to contact the trainers beforehand to arrange for your plans to be adapted for projection or printing, as required.