Case Study: Springfield House

Case Studies

Springfield House, located in Honingham, Norfolk, is a Code 6, 2-bedroom, new build dwelling in a rural setting. The project was also featured on Channel 4’s Grand Designs.

Role of NBT

In order to meet the requirements for this project, which was one of the lowest impact schemes ever being built in Norfolk, all of the materials we used had to match the stringent requirements of low energy, low impact and sustainability.

NBT were involved all the way through the design process, advising on specification and technical support to achieve the ambitious targets of Code level 6. Detailed design support was provided for all the key elements of the thermal shell too.


The key areas in which NBT assisted were:

  • Specification of high performance woodfibre insulation for the walls
  • Detailed design drawings
  • Detailing for airtightness
  • Supplying specified products


Challenges Faced

The bespoke design requirements were the biggest challenge for NBT. Work was needed to facilitate intersections of different façade finishes. A suitable texture for the render finish was created, and after a lot of experiments a suitable lime render texture and colour were identified.

Materials and Products Used

The materials used included Pavatherm Plus for the open cedar timber cladding. Diffutherm with Creativ Top lime render was also used (the timber studs were filled with blown cellulose insulation). The structure utilises the open timber cladding on the ground floor with the render used on the lower ground floor.


These materials and the way they were used were the best in order to meet the requirements for ‘low environmental impact’, ‘exceptional quality’ and design to ‘the highest architectural standards’ (as stipulated by Paragraph 55 of the National Planning Policy Framework). NBT materials enabled optimum of breathability through the thermal envelope of the building.

Project Statistics

Floor area: 168m2
EPC rating achieved: A


Airtightness Level achieved: target was 3 m3/m2/hr. As built was 1.2 m3/m2/hr
U-Values achieved: U values of wall 0.14, (roof 0.14, floor 0.17 neither were our systems)
Primary energy use: 45 kWh/m2/yr

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