Norwichs experience of Passivhaus development 21st May 2019 Gwyn - - PowerPoint PPT Presentation

21st May 2019 Gwyn 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
• f 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

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.

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?