Retrofit for the Future - Whitehaven, Cumbria

Principal Investigator(s): Professor Rajat Gupta


Project start: September 2010

Project finish: December 2013

About us

Improvement to 1930s semi-detached properties

This retrofit project follows a ‘low-energy first then low-carbon’ approach by encouraging energy demand-reduction measures first, and then deploying a nominal level of well-proven zero-carbon technologies that can be easily integrated into the urban fabric.

The case study house is a 1930s three bed, semi-detached property (area: 76m2) located in Whitehaven, Cumbria. The house is representative of the numerous other properties on the estate which prove more difficult to let due to their construction and lack of insulation. This makes the building very cold in winter and hot in summer, and very susceptible to condensation. The challenge for this project, therefore, is to upgrade the existing fabric and achieve deep cuts of about 69% in CO2 emissions by fabric measures first.

A semi-detached property with unfilled cavity walls is a type widely found in the UK housing stock (about 25%), so the solutions proposed in this project have a wide applicability and scalability, given that there are 860,000 social housing homes with unfilled cavities. More specifically, as per the 2006 domestic energy fact file, about 11% of UK housing lies in the north-west, a large part of which are un-insulated unfilled cavity homes. Clearly the case study represents a significant part of the social housing stock. Also, Home Group Housing own in excess of 11,000 properties throughout the region and this scheme would be used as a pilot for future regeneration schemes. The proposals are replicable to different types, eras and orientations of low rise housing.

Thermal imaging of toilet


Rajat Gupta

Professor Rajat Gupta

Professor of Sustainable Architecture and Climate Change, Director of OISD and LCB Group

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The overall objective is achieved by deploying an energy-efficient and air-tight building fabric with stringent U-values and minimal thermal bridging, leading to a 69% reduction in energy use and emissions over the baseline. Beyond improved efficiency for appliances, lighting and renewable energy systems other unique features of this approach are:

  • Minimise fuel bills for the tenant.
  • Encourage a low-maintenance 'fit and forget' approach - crucial in the social housing.
  • Use tried and tested materials and technologies that already exist in the UK supply chain, leading to a practical, cost-effective, replicable and scalable solution.
  • User-centred approach: Pre-retrofit in-use monitoring and occupant feedback surveys were undertaken to understand the actual in-use characteristics of the house, and what occupants feel about it. This helped to select appropriate improvement strategies which will minimise unintended consequences and re-bound effect. A bespoke real-time monitoring and feedback system is incorporated to empower occupants to monitor and control energy use.
  • Improve health, comfort and wellbeing of occupants: Extra measures are incorporated, such as use of low-solvent paints to improve the indoor air quality and water-efficient fixtures to conserve water.
  • Impact on social housing: Use lessons to help Home Group rollout their housing stock.

Project details

Funded by:

  • Technology Strategy Board

Project partners:

  • Roland Hill Ltd.
  • Architects Plus - Carlisle


  • Home Group Housing


Research reports

  • Review of post-completion and early occupation items - Design team interview, Handover & Occupant Interview, July 2011

Blogs and diaries

  • Retrofit for future diaries, July 2011
  • Home Group (NW) Retrofit for future blog, August 2010