This added to the accelerating effects of climate change will inevitably drive governments to encourage saving of fossil energy and penalise its over-use by fiscal and other means.

The introduction of Energy Performance Certificates for buildings will affect property values, with energy efficiency-related variations growing over time and buyers and tenants seeking out homes with lower running costs.

Resulting from all the above, pay-back times on energy-efficiency measures and renewable energy microgeneration systems are shrinking.

The market for renewable energy systems is fast-growing but is fairly impenetrable by non-specialists. Quality of advice and pricing are very variable. Fortunes are being made and lost and the customer is in a very vulnerable position.

In the past, the choice of methods for heating and powering a building was limited and simply made. However with the arrival of a great variety of renewable energy options it is now broad and complicated.

The most cost-effective arrangement for a particular building will involve some combination of insulation and draft-proofing measures, heat recovery, gas, oil, wood (logs, chips or pellets), heat pump (ground, air or water-source), solar (thermal or photovoltaic), micro-hydro or small-scale wind.

The suitability of the myriad combinations of these systems is very site-sensitive. The difference in the capital cost and the payback between the right and the wrong choice can be huge – a fast payback or no payback!