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Carrow Road

Broadland Housing Association is preparing proposals for a new build riverside development of 250 apartments and commercial uses. The scheme is being designed to Passivhaus standards.

Passivhaus evolved in Sweden and Germany that have different climates to Norfolk. The intention of the D4FC project is to model future climate change on the first phase of approximately 46 flats and a commercial unit to develop a future proofed Passivhaus standard for the East of England climate.

Lessons from the project shall be incorporated into Broadland Housing Association’s wider development programme.

This is a client led project.

Further project details

1. What approach did you take in assessing risks and identifying adaptation measures to mitigate the risks?

The project is still at an early stage.

The full design and technical team from the Carrow Road development has been commissioned to be involved in the D4FC, so as to ensure maximum integration of lessons into the project and maximise dissemination throughout our consultant base.

Consultants were required to research future climate issues within each of their professions and review available D4FC1 reports to ensure a good base level of knowledge.

Findings were presented to the wider group at an initial workshop that led to a brief for the University of East Anglia to prepare future climate data.

Consultants then considered the relevant parts of Bill Gething’s three areas of climate impacts to highlight risks and propose options for adaptations.

This was presented to the project team at a second workshop where potential adaptations were shortlisted in terms of costs, practical application and likely buy-in from the client.

2. How have you communicated the risks and recommendations with your client? What methods worked well?

The consultant team has just embarked on designing adaptations for costing by the quantity surveyor. These will then be presented to the members of the client team who control the budget. The project manager is also a member of the client team and so has been able to offer direction and keep other members of the client team informed of general progress to increase the likelihood of buy-in.

3. What tools have you used to assess overheating and flood risks?

Comfort: the climate change data is relatively confident of increased temperatures. This has allowed the architect and Passivhaus consultant to undertake risk assessments of increases in temperatures on the building. The project has recently acquired TAS BIM software to allow the architect to model these scenarios in more detail.

Construction: the climate change data appears unable to predict changes to wind speed and rainfall. Incremental increases of five per cent and 10 per cent have been modelled for wind speed. Cladding material manufacturers have been consulted on adapting to higher wind speeds. The use of timber cladding and window reveal detailing are being reviewed to mitigate the impact of greater driving rain.

Water: the project fronts the River Wensum whose catchment covers much of the Norfolk. It is estimated that over a third of rain falling in Norfolk will eventually join the river upstream and pass the site making it susceptible to flooding. In the absence of climate change data for rainfall five per cent and 10 per cent increments in flood levels have been modelled. The 1 in 100 flood level has been overlaid and found to accord with the highest flood in modern history that took place almost 100 years ago in 1912. The design of the residential element of the building above a commercial unit means it will not be directly affected by higher flood levels. However, it will be effected by flooding of the means of escape from the building to dry land.

Consulting engineers have advised that the site and Norfolk generally lacks the London clay soils associated with heave during droughts. East Anglia has always had a semi-arid climate and been dependent on plant selection and irrigation for forestry and agriculture. Droughts are forecast to increase. The landscape architect is reviewing landscape design, plant selection and irrigation.

4. What has the client agreed to implement as a result of your adaptation work?

The project has yet to formerly report to the client.

Experience of working with the Code for Sustainable Homes for many years shows that clients, construction teams and end users are often confused by unclear climate data and overtly academic and impractical technical solutions.

Where possible the project team is adopting practical and cost effective approach to risk assessments and adaptations to ensure that methodology and findings are easily comprehended by the client. Where possible the aim is to devise straightforward and rule of thumb solutions that can be simply disseminated to the wider client and consultant base.

5. What were the major challenges so far in doing this adaptation work?

  • Obtaining credible climate change data.
  • Keeping the project team focused and not allowing consultants to get into too much detail in their own specialist areas.
  • Financial pressures on the client in the current economic climate.

6. What advice would you give others undertaking adaptation strategies?

  • Do not let your consultants get too carried away with the what-if scenarios for climate change. Climate change forecasts need to be based on sound data or simple plausible predictions to have credibility with clients.
  • Being realistic about the size of budget that a client is likely to entertain for adaptations.
  • Providing clear and concise data and recommendations to the client to allow climate risks to be assessed and decisions made amongst the many other issues that need to be considered.