Gas and electricity are going to become very expensive - while we prattled on not deciding on nuclear but building windmills, our power stations got old. We left building more nuclear too long and now their will be a gap between a lot of nuclear going offline and new coming online.
Gas - well, I think we may have 10-15 years of reliable supply left unless we find more and cut back on what we are using now.
That is a graph of how much gas we have used, how much we know we have and a hopeful estimate at how much we might have, I added the red lines. The top red line is how much we might have, the middle red line how much we have used and the bottom red line is used to indicate how fast we are using gas - as we have around 7 billion cubic meters left, I drew a line 7 billion c/m lower than the gas we have used.
We have used 7 billion cubic meters in the last 10 years.
Any new building is going to be using up the gas that will run out in little over a decade - thus meaning that new heating systems will have to be retrofitted at a much greater expense than if they were put in at construction.
Some renewables can be expensive, but I really really do not know why shallow (as opposed to deep geological heat) ground source pumps are not mandatory on all new builds.
Plan on how you are going to heat your home in the future. I expect a lot of people will be going over to solid fuel - if you plan on wood, you are going to need to buy some woodland.