Wst 05 Adaptation to climate change

Aim

To recognise and encourage measures taken to mitigate the impact of extreme weather conditions arising from climate change over the lifespan of the building.

Assessment criteria

A number of BREEAM issues within the New Construction scheme contain assessment criteria which aim to support mitigation of the impacts of extreme weather events arising from climate change. The main credit in this issue focuses on structural and fabric resilience not covered in other issues. An Exemplary credit is awarded where a holistic approach on adaptation to climate change has been covered, demonstrated by achieving credits in other issues.

The following is required to demonstrate compliance:

One credit - Structural and fabric resilience

1. Conduct a climate change adaptation strategy appraisal for structural and fabric resilience by the end of Concept Design (RIBA Stage 2 or equivalent), in accordance with the following approach:
   1. Carry out a systematic (structural and fabric resilience specific) risk assessment to identify and evaluate the impact on the building over its projected life cycle from expected extreme weather conditions arising from climate change and, where feasible, mitigate against these impacts. The assessment should cover the following stages:
      1. Hazard identification
      2. Hazard assessment
      3. Risk estimation
      4. Risk evaluation
      5. Risk management.

Exemplary level criteria – Responding to climate change

A holistic approach to the design and construction of the current building's life cycle, to mitigate against the impacts of climate change, is represented by the achievement of these criteria.

The following outlines the exemplary level criteria to achieve an innovation credit for this BREEAM issue:

2. Achievement of criterion 1, the structural and fabric resilience criterion in this issue, and the following criteria points or credits:

Hea 04 Thermal comfort

(Link to Wst 05 issue: to prevent increasing risks of overheating)

• Criterion 6 in the second credit of the Hea 04 issue has been achieved.

Ene 01 Reduction of energy use and carbon emissions

(Link to Wst 05 issue: to maximise energy efficiency contributing to low carbon emissions resulting from increasing energy demands)

• At least eight credits in this issue have been achieved.

Ene 04 Low carbon design

(Link to Wst 05 issue: to maximise opportunities to avoid unnecessary carbon emissions)

• The Passive design analysis credit in this issue has been achieved.

Wat 01 Water consumption

(Link to Wst 05: to minimise water demands in periods of drought)

• A minimum of three credits in this issue have been achieved.

Mat 05 Designing for durability and resilience

(Link to Wst 05 issue: to avoid increased risks of deterioration and higher maintenance demands)

• Criterion 2 relating to material degradation in this issue has been achieved.

Pol 03 Surface water run-off

(Link to Pol 03: to minimise the risks of increased flood risk and surface water run-off affecting the site or others)

• Flood risk – a minimum of one credit has been achieved.
• Surface water run-off – two credits have been achieved.

Checklists and tables

None.

Compliance notes

Methodology

Hazard identification

1. Review the evidence/information from relevant bodies to identify and understand the expected impacts of increased extreme weather events for climate change on the building.
2. Identify likely hazards (see Wst 05 Adaptation to climate change).

Hazard assessment

1. Identify the scale of the hazards identified.

Risk estimation

1. Identify the risk presented by these hazards to the building and the likely impact of the hazards taking into account the following aspects as a minimum:
   1. Structural stability
   2. Structural robustness
   3. Weather proofing and detailing
   4. Material durability
   5. Health and safety of building occupants and others
   6. Impacts on building contents and business continuity.

Risk evaluation

1. Evaluate the potential impact of these risks on the building.
2. Determine the tolerable risk threshold.
3. Check the sensitivity of the risk assessment.
4. Identify areas where the risks are unacceptable in health and safety, life cycle assessment and financial terms.

Risk management

1. Identify risk reduction measures.
2. Mitigate the hazards as far as is practically feasible.
3. Adapt the design/specification to incorporate the measures identified by the risk assessment in the final design.

Evidence

Additional information

Relevant definitions

Durability

The ability to withstand wear, pressure, or damage.

Hazard

A hazard is a situation or event which has the potential to cause harm. It may be an accidental or a malicious action, insufficient strength or resistance, or excessive deviation from intended limits.

Resilience

The ability of a building or structural system or material to withstand an accidental or exceptional loading or other incident without experiencing an undue degree of damage or decrease in performance, such that progressive collapse, loss of performance or disproportionate degree of damage occurs.

Structural and fabric resilience

BREEAM defines this as the ability of a structure to withstand an increased burden of weather/increase pressure/hazards associated with climate change. Examples of increased pressures/hazards include:

• Solar radiation
• Temperature variation
• Water/moisture
• Wind
• Precipitation e.g. rain and snow
• Extreme weather conditions: high wind speeds, flooding, driving rain, snow, rainwater ponding
• Subsidence/ground movement.

Systematic risk assessment

A structured approach to help professionals identify, evaluate and manage risk, where the reduction of the risks identified is integral to the process.
It includes:

1. Identifying the hazards
2. Eliminating the hazards, as far as reasonably practicable
3. Reducing the risks from each hazard, as far as reasonably practicable
4. Developing the building design to be robust.

Other information

This new BREEAM issue aims to encourage and support efforts to mitigate the future impacts of climate change on the building by considering a number of relevant factors during the design stages. BRE have avoided being overly prescriptive with the assessment criteria in order to allow a degree of flexibility in its application and demonstrating compliance, recognising that this is a complex environmental and design issue where solutions and approaches are largely influenced by site location and building specific factors. This places a greater emphasis on the BREEAM assessor to use their judgement in determining whether the project team and the building design has met the aim and intent of the credit and its criteria, using appropriate project information to back their judgement. BRE will endorse the BREEAM assessor's judgement through the Quality Assurance audit where a reasonable justification to award the credit on the basis of project team actions and proposed design solutions is evident. BRE would welcome any feedback on the application of this assessment issue to assist with the evolution of the criteria and inclusion of additional guidance on compliance in future BREEAM versions.

The National Adaptation Programme1National Adaptation Programme: Making the country resilient to a changing climate. Defra; 2013 report has been drawn up by the government, industry and other non-government organisations working together. It contains a mix of policies and actions to help the UK to adapt successfully to future weather conditions, by dealing with the risks and making the most of the opportunities.

The book "Design for climate change"2Gething B, Puckett K, Design for climate change. RIBA; 2013 describes buildings and issues as part of the Design for Future Climate, Adapting Buildings programme, the largest programme focusing on the climate change adaptation of buildings in the UK. This programme from the Technology Strategy Board (TSB) aims to improve the climate resilience of building projects. The book has guidance on construction, including structural stability.

The BRE report3Graves HM, Phillipson MC, Potential implications of climate change in the built environment. BRE Centre for Environmental Engineering: BRE East Kilbride; 2000, Potential implications of climate change in the built environment, discusses climate change adaptation strategies, including some for structural resilience.

BREEAM UK New Construction non-domestic buildings technical manual 2014
Reference: SD5076 – Issue: 5.0
Date: 23/08/2016
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