Passivhaus vs. Creativity?

Let’s Talk About the Issues

Standard

Airtight

Pioneering

Physics

MVHR

High performing

Precise

Energy

Comfort

On-site monitoring

Criteria

Third-party certified

Cost

Let’s Talk About the Issues

Standard

Airtight

Pioneering

Physics

MVHR

High performing

Precise

Energy

Comfort

On-site monitoring

Criteria

Third-party certified

Cost

Comfort – our responsibility

Energy – is Passivhaus necessary?

Source: Passivhaus Trust, 2019

The Good Stuff

• Informed decisions

• Bottom up approach

• On site monitoring and third party certification

• Energy resilience

• Simplicity of use and function

The Challenges

• Aesthetics and pull towards box-like buildings

• Inherent difficulty in achieving desirable spaces, particularly upper floor externals

• Design and construction rigour

• Early design/Design cost

• Lacking widespread skills

Croft Gardens, Cambridge

Passivhaus design requirements were made part of the project at an early stage Another design complexity, among others Brownfield, semi-urban site added further design constraints, including: - Acoustics - Orientation - Cost - Planning - Landscape

Croft Gardens, Cambridge

Design ‘work’

Design for airtightness

Higher levels of thermal performance

Some material limitations

Quality of detailing

More intensive focus on cold bridging

Quality of workmanship

Design ‘challenges’

Care not to move too far into a diluted ‘fabric first’ approach – needs to work with MEP systems and building as well

Harder to gain recesses / façade modelling

Limitations of products

Orientation

Working closely with the idea of windows in wall

Don’t forget the ‘other’ stuff!

Design positives

Mass, solidity, tends toward simple forms

Can use alternative products but need to additional work

Clarity of ‘zones’ and ‘lines’ within fabric has benefits in construction

Resilience of design

Design with quality, hopefully for longevity

Simplicity

Kellogg College, Oxford

Lessons learnt

Simple form

Maximised orientation

Challenges of rooflights

Terminations to air in brickwork

Strategic detailing – relationships, positioning and consistency

Thermal efficiency

Style vs. Function?

Passive design does not replace architectural design

Challenges in making

New skills – understanding airtightness, thermal performance and bridging.

Materials and products

Importance of sharing process with teams

“I have never been forced to accept compromises but I have willingly

accepted constraints.” -Charles Eames

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