The answer is simple … Glasshouse!

There are many reasons for this, and I will try to explain them all in the text which follows, but at the end it boils down to one thing:

If you are planning to invest in a serious, long term, industrial scale vegetable production… then the glasshouse is a natural and logic choice because it provides more security and stability during the  production cycles.

Here are some more advantages of the glasshouse compared to a foilhouse:

Higher Light transmission

Glass has a light transmission between 89-91% and it stays constant during its lifetime.  Glass is not effected by UV radiation and can be cleaned by special machine if it gets dirty.

Foil has lower light transmission and it gets lower with each passing year.

Higher life time

Glass lasts forever, if not broken.

Foil has to be changed every 3 -5 years. this replacement needs to be done by a specialized team, cant be done during windy or low temperatures. So at that season, during the foil replacement some interruptions in production will happen for sure.

Cost

Glass and a Glasshouse itself maybe cost more initially, but replacing foil every 3-5 years also cost a lot… material, labor and disturbances in production.

Climate

It is shown by experience that humidity control and humidity related plant diseases is much easier to control in a glass covered greenhouse compared to a foil greenhouse.

Storm (wind) resistance

Glasshouses are typically stronger and more resistant to high winds and snow.

Disadvantages

Only disadvantage of a glasshouse would be hail resistance. But when it comes to hail, statistics comes in. Not every size hail is dangerous to a glasshouse. There are smaller and moderate hail storms which do not effect the glasshouse in any way. Bigger pieces of hail might brake few sheets of glass here or there, but then there are repair procedures and materials for that. Also if a big hailstorm comes with large pieces of hail, they are rare and glasshouse owners are usually covered with financial insurance both for the glasshouse, equipment and production.

Like mentioned before, hailstorm damage is a matter of statistics and a job for an insurance company. From experience in the field, glasshouse investors are not that worried when it comes to hail.

Another “advantage” of a foilhouse is lower investment cost. But if you take a closer look at the total investment in the new greenhouse project, if you calculate the installed equipment, land and building work, cost of financing etc… difference in cost of the greenhouse structure and covering between a foilhouse and a glasshouse comes down to bellow 10%. So usually investors decide to pay this few percentage more and go for a glasshouse.

And here I talk about a normal foilhouse with a normal foil.. not ETFE or some other very costly, space foil.. This is another subject.

Also there are projects in very warm and dry climates with special productions and a low total investment cost per m2, where foilhouse just makes more sense. But that’s for another post…