PASSIVE HOUSETHOUGHTS FROM SOMEONE WHO’S BEEN THERE

(and may not be going back !)

Ed O’Donoghue

OVERVIEW• Introduction• Preparing for a high quality build• Real World Issues• Overarching issues • DISCUSSION

INTRODUCTION

• ME WHEE………….

• WHY BUILD QUALITY HIGH PERFORMANCE BUILDINGS ?

• DON’T UNDERESTIMATE THE IMPACT YOU CAN HAVE

INTRODUCTION

HELP

Preparing for a High Quality Build

Preparing for a High Quality Build• COLLABORATION

• IF YOU HAVEN’T DRAWN IT YOU HAVEN’T THOUGHT ABOUT IT

• MOTIVATE, EDUCATE, EDUCATE, EDUCATE

• BE PREPARED TO COMMIT TO ON SITE MONITORING

REAL WORLD ISSUES - FOUNDATIONS

SAWTOOTH EPS FOUNDATION G/L ELEMENT FOUNDATION

REAL WORLD ISSUES - FOUNDATIONS

REAL WORLD ISSUES - FOUNDATIONS

• Evolution of traditional method• No specialist knowledge• Thermal block MUST be kept dry• €130/m2 average cost • Transferable to timber frame

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TRADITIONAL STRIP FOUNDATION ψ = - 0.122 W/mK

€/m2Average

REAL WORLD ISSUES - FOUNDATIONS• If UFH then 150mm screed depth ok• Standardised look-up table calculations for wide cavities• Window & Door threshold details – be brave• Plan service exits, especially first floor• Collaboration between radon protection, thermal block and damp

proof requirements

REAL WORLD ISSUES - TEAM

• Knowledge of Passive House limited to architectural team member• Structural engineers are not aware of the issues and……….• Project team is normally contractor & client post build• Design competence and supervision is not valued• Site foreman is Passive House champion – they rule by fear• Construction industry does not do quality• Construction industry does not do education• Spirit of collaboration does not exist• Electrical & mechanical services is not considered in residential design

REAL WORLD ISSUES - DETAILS

• ACD’s suck• Key to success is junction detailing• Raise the bar – can we draw these details in 3D ?• Standardise details, calculate them and share• Done right they can save money

REAL WORLD ISSUES - VENTILATION• Locate unit close to external wall• Keep inside thermal envelope• Adopt commercial level detailing to design• Commission in accordance with PHPP requirements• Understand airtight sealing and insulation requirements of ducting• Design needed pre-build to ensure efficient layout & operation

REAL WORLD ISSUES - AIRTIGHTNESS• Designer responsible for strategy and detailing at junctions• Good design = cheap and effective on site• 0.6 ACH very very difficult on double leaf cavity • Timber frame is best solution from a QA point of view• Learn by doing• Ensure certified product is used & operatives formally trained

OVERARCHING ISSUES

• There will always be resistance to change – be brave• Quality assurance and education are a challenge• Passive House exacts standards far beyond conventional expectations• Communication of Passive House needs to improve• This is a good thing to do – stick with it• It’s a movement and a community• Your grandchildren will thank you• BE POSITIVE

THANK YOU

www.edmondodonoghue.com