Making Old Buildings more Energy Efficient

One aspect of sustainability that is very relevant to me is energy efficiency in older buildings. Like many others I live in a so-called ‘period’ house and whilst it’s a nice house to live in, after having built highly insulated buildings I know just how much I’d love to live in a building that requires very little in the form of active heating. It is estimated that the UK’s current housing stock is responsible for about 27% of the UK’s total carbon emissions.
Existing older buildings require careful consideration when it comes to improving the insulation of solid walls. Changing the thermal dynamic of a solid wall could allow condensation to form causing damage and maybe even reducing the thermal performance of the wall!

So many questions… Is the building listed, is it in a conservation area, will an external insulated system ruin the look of your house, if you apply insulation internally how much space will be lost, and what about that nice original cornice? And what about those original sash windows – surely it would be criminal to replace them! Do you install secondary glazing or maybe you could replace the single pane of glass with a single pane of low e glass?

I came across a FAQ at the Pilkington wedsite where, with qualifications, they say that K glass can be used in single glazing.