INSULATE BRITAIN. What does that mean?

This has been the cry of activists who obstruct traffic by glueing themselves to roads and creating general havoc. Some may admire their motives in consideration for future generations, as we adapt to abolishing the usage of fossil fuels. However making a confounded nuisance of onself is not the way to make friends and influence people.

In any case the message is very broad and unclear. What exactly is the course of action that the government is being demanded to take?

When I moved in to my present house, it had cavity insulation, double glazing all round and loft insulation. I found that the loft insulation was thin and inadequate, so I augmented it to meet the recommended standards of the time (about 30 years ago). Ostensibly it ticks the most-important boxes. However I have no doubt that a surveyor could suggest further improvements. Have standards for loft insulation been raised further? (If so, a lot of upheaval.) How about fitting a draught-proof letterbox? Could we improve the sealing round some doors and windows? And so on.

Over the years I discovered a problem that creates a much bigger heat loss than any of these latter-day remedies would save. Upon lifting floor boards to run wires, I was appalled to find no insulation on any of the pipes carrying hot water. I surveyed to house to estimate the likely total length of central heating pipe. I calculated the surface area to be roughly equivalent to a largish radiator. That is well over a kilowatt of wasted heat. Little of this heat is likely to find its way through boards and carpets into the rooms above. Most of it will be blown away through air bricks. It would have been easy enough to install this insulation along with the pipework, but to add it retrospectively would be prohibitively disruptive and expensive.

In my opinion, any pipe carrying hot water for any purpose should be insulated. The only exception would be pipes above floor level leading directly into radiators. I hear little in the media about the importance of pipe insulation, but plenty about things like not leaving the TV on standby, saving about a watt.

We can also consider pipes carrying hot water to taps. We are familiar with the frequent need to run off cold water to reach the hot. This represents wastage of water, energy and time. I did some checks in a washroom handbasin. I measured seven litres of water run off before hot water emerged. I also checked how much hot water would pass if I cleaned my teeth with the tap running. One litre! Again the common energy saving advice focuses on the wrong targets. When our kitchen was refitted, hot pipes were temporarily exposed. I took the opportunity to insulate them. This made a notable difference in how often cold water needed to be run off from the kitchen hot tap.

I have little doubt that new houses are being built with standards of insulation far higher than can be achieved by my own. Older housing will continue to exist for very many years. We will need to accept that we need to strive to produce enough renewable energy to cover the unavoidable losses due to the poorer insulation of older houses.