Passivhaus in the UK - are we making progress Liz Reason, Director, CarbonLite

2. The UK government has ambitious ambitions

3. And has devised the Code for Sustainable Homes for starters

13. We need a clear pathway to the destination of low energy buildings Know where you�re going Understand energy in buildings Adopt the best components, tools and techniques Measure how well you did Close the feedback loop

14. Three standards underpin CarbonLite

15. Why model CarbonLite standards on Passivhaus and PHPP? The standard A carefully developed low energy building standard Promotes design of cost-effective energy efficiency solutions Focuses on getting the fabric right Performance-monitored Gaining credibility throughout Europe and beyond PHPP (PassivHaus Planning Package) Two specific energy targets space heating 15 kWh/m2.yr primary energy 120 kWh/m2.yr Models buildings as a system and encourages low energy solutions throughout Optimises passive solar gain Promotes and assists designers to achieve low energy solutions Provides reasonable predictions of energy use for meeting CarbonLite standards

16. In the first instance, the UK regime differs in key respects from the Passivhaus standard The UK A CO2 target prompts carbon-saving solutions which tend to be expensive kit Expressed as a % target reduction against a notional building whose parameters are not fixed It is possible to achieve compliance by worsening the base case Focuses on the fabric standard but is ambivalent towards non-fabric energy Compromises the fabric standard Passivhaus Two energy targets space heating primary energy Specific energy targets 15 kWh/m2.yr space heating 120 kWh/m2.yr primary energy Focuses on fabric standard and applies and accounts for low energy design at the whole building

17. The key findings: When modeling well-insulated low energy dwellings, we found: PHPP tended to predict higher heating requirements than SAP SAP predicted no heating at all (where in practice some heating is needed) Because there are no fixed energy limits, inefficient built forms are favoured rather than penalised SAP indicates that carbon savings can only be delivered by expensive kit before using useful energy efficiency measures

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21. Ventilation losses overestimated Fabric losses underestimated

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23. We need to change UK culture � We�ve � been too relaxed about energy in buildings muddled our metrics oversimplified SAP to make it accessible to a broad range of users used fudges without understanding the implications and incentives they create undervalued energy expertise and divorced it from design failed to exploit the energy expertise we do have

24. Set up a new organisation To focus on the Passivhaus standard and methodologies To provide leadership To build capacity in people and products To expand the market