Payback time.

In a recent survey of quantity surveyors, most believed that energy-efficient buildings are more expensive to build than conventional ones. But it isn't necessarily so by any means.

A software approach for economic optimisation of energy use in buildings.

When designing a new, or retrofitting an existing building it is desirable to minimise theheatinglcooling load, total energy use and emissions from combustion. Solutions toaccomplish this has to be held up against investment costs, maintenance costs,longevity and of course indoor climate (among other things). Optimisation betweenthese different and often competing criteria is complex, and involves a lot ofparameters.

The key to persistence.