Archetype definition

A retrofit assessment for properties is mandatory for all properties going through the retrofit PAS2035 process. Assessments aim to identify opportunities for energy efficiency improvements; determining the most suitable Energy Efficiency Measures (EEM) for each surveyed dwelling. The current process to gather information about properties for retrofitting solutions involves several key steps:

• Occupant assessment: Evaluates the needs and behaviours of the building’s occupants to ensure the retrofit measures will be suitable and beneficial.
• Condition survey: A detailed inspection of the building’s existing structure, including heating, ventilation, and insulation systems.
• Energy report: An analysis of the building’s current energy performance and areas where improvements can be made.

For more information, visit the Energy condition assessments section.

Gathering data on a case-by-case basis is tedious and inefficient and it hinders the potential of creating clear aggregated demand. To understand and calculate the potential aggregated demand for retrofitting solutions, the following approaches are often used:

• Market analysis: Conducting surveys and studies to understand the demand for retrofitting solutions across different regions and dwelling types. This helps identify trends and potential areas with high demand.
• Pilot projects and case studies: Implementing pilot projects to gather data on the effectiveness of retrofitting solutions and their acceptance by property owners. These projects provide valuable insights into the potential aggregated demand.
• Stakeholder engagement: Engaging with property owners, local authorities, and industry stakeholders to gather feedback to understand their needs and preferences. This helps in tailoring retrofit solutions to meet market demands.

An alternative approach is needed to judge every project on a case-by-case basis, if an accurate pipeline is to be determined for retrofit at scale.

There have been attempts to simplify the understanding of the housing stock and the UK’s retrofitting potential, including:

• LETI’s Climate Emergency Retrofit Guide: In this case, a series of house archetypes were developed based on average data for different building types to define the energy use targets for each representative example.
• National Retrofit Hub (NRH) Archetypes Library and Best Practice guide: The NRH recently recognised ‘archetyping’ as a powerful tool to understand or segment building stock:
  • Archetypes library: provides the wider sector with access to existing archetype guidance created by designers, local authorities, and property owners.
  • Archetypes Best Practice Guide: assists those identifying archetypes and designing retrofit interventions based on archetypes to achieve high-quality results tailored to their specific use case.

In this section, we outline key ideas, approaches, measures and policies for shifting towards a thriving retrofit eco-system that can deliver home energy upgrades at speed and scale. All points are drawn from project research and consortium partners’ experience.

Transform-ER has adopted the Construction Innovation Hub’s Demand > Develop > Deploy structure. The ‘Demand’ phase involves identifying market demand and understanding the needs that industrialised retrofit solutions aim to address.

“Through the use of platforms – common, repeatable assets with interoperable components – [our rulebook] aims to drive a new market for manufacturing in construction, to provide a predictable pipeline of demand that affords industry the confidence to invest in new products and technologies and to create stable and inclusive employment where jobs are most needed.” Construction Innovation Hub’s Product Platform rulebook

To have a predictable pipeline, the use of archetypes is key. Transform-ER’s Define the Need report introduced the benefits of targeting a group of homes with common features represented by the ‘archetype’, to simplify and scale up retrofitting and provided the first industry definition.

Defining an archetype in a retrofitting project can deliver benefits including:

Improved forecasting of the project pipeline

• Predictable outcomes
• Scalable planning
• Prioritisation of projects

Modelling archetypes instead of all homes in the first instance

• Cost-effective modelling
• Reduction in complexity
• Consistency
• Enabling more private capital
• Appropriate ‘net-zero pathways’ selection

Selection of optimum targets and technical solutions

• Targeted solutions – suitable products and kit-of-parts
• Compensation for variability
• Flexibility in implementation

Data-driven decision making

• Data collection & analysis
• Learning from similar homes

Facilitates stakeholder communication and engagement

• Clear communication
• Strategic partnership
• Finance products
• Delivery risk

See below for a deep dive on how to build an archetype.

Questions

• Does a British Standard need to be developed for archetyping? 

Enablers

• New digital tools that can support portfolio analysis, management and demand aggregation.

Guidelines

• The more categories defined by a project, portfolio or consortium, the greater understanding of the pipeline of demand for stakeholders.