With air conditioning pretty well standard on most models these days, you may have thought that sunroofs were behind us – but they are making a comeback.

And they are considerably more exotic than the old ‘cut-outs’ of the past.

Such models as the Renault Espace, Peugeot 407 estate, and the upcoming new Volkswagen Golf Estate (wagon) are just three models with the option of panoramic sunroofs.

These have to be engineered into the car right from the beginning, according to Hans-Gerhard Gebauer, the man in charge of roof systems at Volkswagen. Two, and sometimes three, glass panels are being used, stretching almost length of the roof.

“The point is not so much about ventilation or air flow, but getting as much light into the vehicle as possible and to create almost a convertible feel to the car,” said Gebauer.

“But it is important that you do not lose the strength from the body shell, of which the roof is an important part.”

In the new Golf Estate, the frame of the two-panel panoramic sunroof is part of the strengthening along with additional consoles in the B-pillars for side impact protection.

It’s not just a case of putting in a bit of glass either. This has to be toughened so as not to shatter in the event of a crash; it also has to be treated to prevent harmful sun rays from fading or bleaching interior fabrics and plastics. Then there are the electronics involved in opening and closing.

The VW’s sunroof is supplied as a complete ‘module’ by two component companies, Arvin Meritor and Webasto.

Where will sunroof technology take us in the future? Weight is an issue, and particularly as it adds some pounds where you really don’t want them – at the top of the car.

Gebauer said: “We are working with suppliers on polycarbonates rather than glass but we are still having problems with scratch resistance. I think maybe we will start seeing them in two to three years.”

Currently the sunroof glass is tinted but there are no plans to investigate the use of photo chromatic panels due to cost – almost double the price.

The new Golf Estate will be launched in the UK in August starting at around GBP14,300 for the entry-level 1.6-litre S model.

Volkswagen UK expects to sell 2,800 in a full year with diesel accounting for 88% of sales.

How many buyers will go for the panoramic sunroof option? The company is not sure right now, but at launch in Germany on 1 June it will add an additional EUR1,130 (GBP773) to the price.

See also: Global market review of automotive roof systems – forecasts to 2013