I would like to respond to Ben James’ letter (BSj 03/05) on energy use and CO2 emissions, as it raises several important points.

Clearly we have reached the appropriate levels of insulation for new buildings and a change in emphasis is needed. I agree that this should be a serious effort to ensure compliance with Part L of the Building Regulations at both design and delivery stage. If this is achieved we will produce new building stock that requires low energy input to maintain comfort.

There remains one more “obvious” thing to be addressed from the UK climate change strategy. I have seen many presentations that break down the carbon use of the built environment in the UK and all show a huge percentage to be heat. Yet whenever ministers talk about energy they always speak about electricity.

But they are missing the point and the consequences could be terminal. We have a heating problem not an electrical supply problem: we need to heat our current building stock. To reduce this need we could insulate. But think of the true impact of overcladding every building in the country. Can we do this? Would it not be better, quicker and cheaper to think as heating engineers with a big heating problem?

Our country’s heating is largely supplied by two major sources:

  • natural gas to boilers and water-based heating distribution within buildings
  • electrical energy through wires and resistance heating within buildings.

In the future we need either a non-carbon replacement for natural gas or a water-based heat distribution system, or massive changes in our electrical grid to deal with wholesale conversion to electrical heating.

The interesting point, which to date has received insufficient discussion, is the urgent need to develop an infrastructure that can get heat to our buildings in the post-fossil-fuel age. I think we should develop a water-based solution: as a way of moving heat around, it is hard to beat and ensures the widest possible choice of heat source.

In my opinion its temperature should be as low as possible, ideally low enough to avoid insulation, maybe with heat pumps in the buildings to match existing heating systems.

So is the future infrastructure electrical, hydrogen gas or water? Or are we going to rebuild and overclad? I would love to hear readers’ views and really get the problem out into the open.

Andy Ford CEng FCIBSE, director, Fulcrum Consulting, London

Source

Building Sustainable Design