Norwich’s experience of Passivhaus development · Monitoring data • 85.7% said they would now...

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?