Energy efficiency for reasons of economy, comfort and, reducing carbon emissions are a major priority. Economy because we all want to save money and there is only one direction that fuel bills go. Comfort – who would want to live in a cold home with draughts which adds not only to the economy argument but also the emission part of the trilogy.
Carbon emissions in my view is the big one, an extra jumper or thicker curtains will mitigate to a certain extent the issue of comfort but carbon emissions affects us all.
The amount of energy required to manufacture PVC-u windows and doors will take many years before it is off set buy savings in reduced emissions achieved by installing them if ever and there is to my knowledge no recycling of these units which are now becoming a landfill problem.
A whole building approach by that I mean looking at all possible ‘heat sinks’ can help in reducing waste.
The heat loss from windows can vary considerably it depends on the size of the window in ratio to the external wall. Heat can be lost through poor installation and ill-fitting sashes, conduction through the glass and from radiation through surfaces.
Retro fitting draughts excluders and brush seals outlined else where on this site can dramatically reduce draughts, bear in mind draughts can move in two directions into the room and out of the room. Research has shown that fitting these simple seals can have an 80% impact reduction. Another benefit also is the acoustic proofing that results from these seals.
On the subject of research, thick curtains the sort my mother used to hang at the beginning of every winter- they were made from a second hand stage curtain which once hung at the old Atherly Cinema in Shirley can have the same thermal impact as double glazing. Not that we all have second hand stage curtains but you hopefully get the message.
Incidentally double glazing multi-paned windows will not give you the same thermal efficiency as secondary glazing either as there will be thermal bridging through the numerous glazing beads and frame.
So in conclusion without the need for double glazing to be employed a combination of the correct seals- that is compression seals for windows that close against the frame and wiper seals for parts that move against each other, sliding sashes come to mind. The closing of any gaps around the exterior of the frame. Curtains or blinds and secondary glazing will keep you warm and snug without compromising the aesthetics.