21st May 2019Gwyn Jones
City growth & development
manager Norwich City Council
Norwich’s experience of Passivhaus development
• Housing Strategy 2013- To build minimum of 250 new council homes, let at social rent by 2018
• Environmental Strategy 2015• Priority 5-To ensure that new
development is carried out in a sustainable way.
• Target – 2015-2019- 100% of new homes built by the council to sustainable Homes Code 4 or passivhaus
Why passivhaus?
Norwich’s passivhaus schemes
Norwich City Council
• Hansard close - 10
social units completed
May 2017• Architects Hamson
Barron Smith• Contractor EN Suiter
Norwich’s passivhaus schemes
Norwich City Council• Goldsmith street - 93 social
units – almost complete.
• Architects: Mikhail Riches
• Contractor RG Carter
• Multi award winning!
Norwich’s passivhaus schemes
Norwich Regeneration Ltd• Rayne Park - 172 units (112
passivhaus) under construction.
• Due for completion Autumn 2020
• Largest mixed tenure (& tenure blind) passivhaus scheme in UK
• Part of 1000 home development
• Architects Hamson Barron Smith
• Contractor RG Carter
Challenges
Planning policy Greater Norwich Joint Core Strategy 2014 Policy 3• Decentralised & renewable energy to
provide at least 10% of expected energy requirements
• Larger schemes to maximise provision of energy from decentralised & renewable energy
• Policy emphasis on renewables, district heating not “fabric first”
• Scheme emphasis on energy efficiency not energy generation (MVHR not photo voltaics)
Challenges
Busting the “myths”• Residents need to lead a
different lifestyle• Controls too complicated• Can’t open windows!• Homes will overheat
Challenges
Technical considerations
Designing passivhaus from outset
• Orientation
• Simple building form- size and shape
• Shading strategy
Contractor experience
• Fabric First Framework
Quality control
• New ways of working and attention to detail
• Fabric First Academy
• Passivhaus clerk of works
• Toolbox talks
Solar shading
Norwich Drawloom Shawl (1840) an important shawl for Norwich as it is one of the very few which can be safely attributed to Willett & Nephew, one of the largest and most influential shawl manufacturers in the city.
Challenges
Financial• Higher build costs• Management- components
more expensive to replace/ maintain but whole life costs
• Contractor building in risk• Returns-uncertainty around
premium on private sales
Challenges
For purchasers/ tenants
• Induction hobs- need to buy special pans
• Perceptions- ability to switch off the MVHR
• Noise of MVHR and hearing problems
• It’s not air conditioning!
Social• Reduced energy bills- up to
70%• Addressing fuel poverty• Reducing rent arrears to 0%• Health benefits- air quality-
sleep, allergies etc• No noise; no mould• Overall tenant satisfaction
Benefits of passivhaus
Performance & monitoring
Monitoring data
• 85.7% said they would now either prefer to live in a Passivhaus or only move if it was into another Passivhaus
• 100% were satisfied to very satisfied with their energy bills
• 85.7% said that using the heating was the same or easier than they were used to
• No residents said it was difficult to use the ventilation system
• 85.7% said it was comfortable to very comfortable in their homes all year round
• 100% said the maintenance of their Passivhaus was the same or easier than they were used to.
• British Gas thought a resident had not been living in the property as bills were so low!
Data from Carrowbreck- courtesy of Broadland Growth and HBS
Economic:• Upskill local workforce
(Building Futures in Norwich
Fabric First Academy)
• Opportunities for local businesses
• Sales premium
Benefits of passivhaus
Environmental:• No “performance gap” compared
with Building Regs 2013• Actual performance of new
homes does not match design- (Average new home likely to use 40% more energy than predicted)
• Notionally zero carbon home would still emit 18kg co2/m2 .year
(Source- Passivhaus- The Route to Zero Carbon?- Passivhaus Trust 2019)
Benefits of passivhaus
Future- practical issues
For the council/ Norwich Regeneration Ltd
• Build cost- quantity v quality for council
• Experience of residents- energy savings- need for monitoring/ evidence
• Advance resident briefings
• Delivering best financial return for council
• USP for company
Future- Local planning policy
• GNLP proposed draft policy based on interpretation of 2015 Written Ministerial Statement- local authorities can set standards above Building Regs but not exceed equivalent of Code for Level 4.
• Level 4 agreed to be equivalent to 19% improvement on Part L of 2013 Building Regs.
• Consideration of introduction of national standard to prevent use of fossil-fuel heating in new homes
Future national policy considerations
Passivhaus- only way to achieve zero carbon
• Performance gap
• Disparity between energy demand (heating in winter) & renewable energy generation- requirement for storage/ storage losses
• Limit on amount of energy managed & deployed through national grid
• Non passivhaus would require 28 solar panels to offset energy usage. (Passivhaus would need only 14 solar panels.)
(Source- Passivhaus- The Route to Zero Carbon?- Passivhaus Trust 2019)
Conclusions
• Reducing heating energy demand through a fabric first approach is only practical way to achieve zero carbon homes in reality.
• Local authority housebuilding can set an example and share the learning/ wider (non environmental) benefits
• Costs will come down if more projects developed
• Private housebuilders are unlikely to change practice voluntarily
• This can only be achieved through national policy standards
Questions?