Buildings often use 200% more energy than predicted, emit more CO2 than they should and are uncomfortable to occupy. Even 'sustainable' buildings. This is known as the Building Performance Gap. Passive House design has effectively eliminated the gap - so what can we learn from Passive House Design?
3. If you don't measure
results, you can't tell
success from failure
David Osborne and Ted Gaebler
4. Let’s talk about:
1. What is the building performance gap?
2. Why does it matter?
3. Reasons for the gap
4. Passive House design
5. Results
5. 1. What is ‘the gap’?
When building performance in use doesn’t match
design predictions
1. Energy Consumption
2. CO2 emissions
3. Health and wellbeing
• Comfort
• Hygiene
• Indoor Air Quality
6.
7. What is the gap?
When building performance in use doesn’t match
design predictions
1. Energy Consumption
2. CO2 emissions
3. Health and wellbeing
• Comfort
• Hygiene
• Indoor Air Quality
8. Health and Wellbeing
Comfort
• Air temperature, surface temperatures, temperature
asymmetry, draught-free, relative humidity
Hygiene
• Condensation, mould
Indoor Air Quality
• Fresh air, odours, CO2 levels, moisture
9. 2. Why does ‘the gap’ matter?
People see sustainable design as:
• Woolly
• Well intentioned, but . . .
• Expensive / luxury
• An add-on extra
• Pointless
They are right . . .
. . . while there is a performance gap.
12. Close ‘the gap’ and . . .
Sustainable design is
• Not woolly: clearly defined outcomes
• Not just good intentions: delivers on promises
• Not luxury: what educated clients demand
• Not an add-on: integral to design
• Not pointless: relevant
AND genuinely helps mitigate climate change
13. 3. Reasons for ‘the gap’
1. Design
2. Construction
3. Commissioning
4. Occupation
14. Design
• Designers don’t know the impact of decisions
• No modelling
• Wrong / unknown modelling assumptions
• Wrong assumptions about how people behave
• Designs unbuildable
15. Construction
• Drawings / documentation not followed
• Changes made during construction
• Lack of quality control
17. Occupation
• Complex systems that people don’t know how
to use
• Not educated in using a building efficiently
• Don’t care?
18.
19. 4. Passive House design
• Clear performance requirements
• Rigorous non-prescriptive design methodology
• Modelling integral to the design process
• Design QA
• Construction QA
• Rigorous 3rd-party verification process
• Accountability
20. A focus on what matters
1. Insulation
2. Airtightness
3. Heat Recovery Ventilation
4. Thermal Bridges
5. Windows & Doors
36. Takeaways: to close the gap
• Clear measurable targets
• Model accurately and often to measure design
• Measure completed buildings and learn
• Accountability throughout the process