We don’t need to do that now because we can do it with Google Earth.

It’s a great way of researching an area and understanding it.

“There’s another fantastic tool that I really recommend, on the Defra website, called the Magic Map App.

(natureonthemap. naturalengland.org.uk) It’s a publicly accessible website, and the title page shows a map of the United Kingdom and you can zoom in so that it becomes an Ordnance Survey map, then an even more detailed map.

“You can see all the marine protection zones, the landscape protection zones, listed buildings, habitat and species conservation areas.

In a trice you can see whether a place is protected or whether there is anything that threatens you, for example if it’s a planning zone.

It’s a really great tool.” With his building business hat on McCloud has talked to a lot of estate agents over the past year, who all say buyers are less interested in the number of bedrooms a house has than how much it costs to run.

“Suddenly one of the questions at the top of the list that people are asking, right across the market, is ‘How much will it cost to heat this place, what are the running and maintenance costs?’

People are really interested in the energy costs from the point of view of expenditure and sustainability.

I think that’s very healthy.

“The government research that I’ve seen shows that houses that have been insulated attract a premium of 13-16 per cent over similar houses that are not as well insulated, and houses that are well insulated will sell more quickly.”

McCloud advises potential buyers to ask about the type of boiler in the property (high efficiency condensing boilers are best), to check whether windows are double or triple glazed and to ask about loft and wall insulation.

“Is the loft insulation 200 or 300mms, is it one layer or two?

Is there under-floor insulation?

These are the basics,” said McCloud.

He could go on… but for those who already know the basics, a trip to Grand Designs Live could save you even more.

For information about tickets and opening hours go to granddesignslive.com.

Kevin McCloud is looking for 10 households to take part in a chance to design and build their own home on a site in Oxfordshire, which will be filmed for Grand Designs.

For more information go to channel4.com/programmes/ grand-designs.