The 18 ft & 20 ft (5.4m & 6.0m ) wide standardDutch light Clearspan Glasshouses

The  picture above shows a standard 18 ft (6096) x  60 ft (1847 mm) £17500inc vat.
Prices includes horticultural 3 mm glass, pressure preserved  timber frame, which is treated for life
  Storm proof full width profiled steel reinforcing gables every 5 ft. Erection extra 15% (U.K. only, Europe please ask ).).

With  9 ft ridge height and a 18 ft or 20 ft clearspan these models offer a versatile and comfortable growing
 environment, plants of all descriptions seem to thrive within its natural  warm timber frame.

Also as with a 29 ft glasshouse, extra wide doors can be fitted, allowing access for wide implements / machinery.
“Clearspan” over a large width is advantageous to all growers. These model share the benefits inherent in all our glasshouse designs. Exceptional value for money.
A design which has been proven & refined over more than thirty years.

Even light infusion, good light intensity, warmth of a wood frame, easy attachment of fittings offered by wood frame and storm proof steel gables.

All helps towards healthy early crops 6-7 weeks earlier  in the growing  season.