Information required to complete a Section J building fabric report:

  • Dimensioned architectural plans and elevations (mechanical and electrical if these are available)
  • Window numbering and sizes – preferably supply a completed window schedule so that windows not on elevations can be included. If changes occur, please retain the window numbering for each window as we will reference each window in our glazing calculator
  • Details of proposed or preferred window type (timber, aluminium, single, double glazed, thermally improved frames, clear, low e or tinted glasses etc) and preferred supplier if known
  • Any proposed or preferred construction systems for roof, wall and floors if not clear on plans
  • For a refurbishment details of whether there is any work to be undertaken to external building fabric elements. Also whether there is access to the roofspace/ceiling and below the floor.
If a change of use, extension:
  • Building surveyor’s contact details
  • Original building area and area of extension
If no electrical engineer is engaged and an artificial lighting and power assessment is required:
  • Provide total dwelling, balcony and garage areas for a residence
  • Provide room areas for a non residential building

Information to assist when determining glazing solutions

For non thermally broken commercial frame aluminium windows:
  • U=6.1 and SHGC=0.7 approximates standard commercial single glazed fixed frame clear windows.
  • U values of 4.3 approximates standard commercial single glazed low e fixed windows.
  • U values of 3.5 approximates standard commercial double glazed fixed windows.
  • U values of 2.8 approximates best available commercial double glazed argon filled fixed windows.
  • SHGC = 0.7 approximates clear glass.
  • SHGC = 0.5 approximates a mid tint grey glass.
  • SHGC = 0.3 or less approximates supergrey type tint ie heavily tinted.