Oh, I love a quiz!
Imagine a workshop, twin brick outside walls, no cavity insulation, concrete floors covered in a vinyl layer, single storey, well insulated ceiling with 300mm insulation squeezed under 22mm chipboard loft flooring. Floor area is 100 square meters, ceiling height is 3 meters, windows and doors take up 10% of wall area, and glazing in these is top notch. What would be the likely requirement in KW to keep this building at 22 degrees assuming the stats keep the heaters on to maintain internal temperature regardless of outside temperature?
Or is that just too much of a guess?