We ordered our Keder house (3m x 4m) at Malvern show and it was delivered soon afterwards. The whole thing was neatly packed on a single pallet and there it stayed until Christmas. The Autumn weather was so good we were busy doing other things and then the rains came so we ended up building the house during the Gales around Christmas and New Year.
Unlike building a regular Poly Tunnel the strong winds didn't cause us much of a problem - that's because at no point do you have to drape a full cover over the whole structure with the associated 'kite effect'. The only 'incident' was at the point when the framework was complete and the Keder material was fixed to the ends, these caught the wind a little and the structure popped apart, no harm done and easily fixed - we tied the ends together with a rope and had no further issues.
Luckily I had just bought a powerful rechargeable driver and this made fixing the self tappers through the profile into the tubes reasonably straightforward - you do need a firm hand for this but it's a sweet system and very good way of fixing the Keder material to the structure. We had a couple of queries that were dealt with very quickly by Keder UK and the end result is rock solid despite being constructed in the worst weather for years. Even during the strongest gusts I felt totally confident inside the Keder house - the cover doesn't flap and the extra strengthening keeps it very stable.
The day after it was finished the electrician came and installed a water proof socket, I had already layed armoured cable from our shed to the Keder house. That was a Monday and I installed a thermostatically controlled propagator and sowed Tomato seeds, by Friday they had germinated and have grown away well. Light levels in the Keder house are good, even inside the propagator seedlings get enough light to not get drawn up. The auto vent works well and keeps the Keder house from getting too hot which in turn helps prevent the propagator from cooking the seedlings. On the really sunny days I have opened the rear vent and that combined with the auto vent keeps things just right.
The Keder material that clads the Keder house looks like bubble wrap on steroids, big fat bubbles with an air gap of around 1/4 inch - double film insulation a bit like double glazing and with the same insulating effect. A surprising amount of light gets through what appears to be a slightly milky material, this is down to the light being scattered and spread evenly around the inside of the structure.
As a photographer diffused light is good news, it makes for even lighting and reduced shadows - working inside a Keder house is like working in a giant light tent. Even on a bright day I can work without using a diffusing screen that saves time and a lot of messing around figuring how to hold the screen and camera with just one pair of hands. Another incidental bonus for photographers is the lack of drafts in Keder houses, with the vents closed there is no perceptible air movement, even when a gale is blowing outside delicate flowers keep perfectly still for the camera.....and if it's raining I stay dry!
The insulation effect of the Keder material makes it worth adding a little heat - unlike in a glass house the heat doesn't all leak away so tonight when the frosts return I will sleep soundly knowing my tender seedlings are safe. I had dreamed of getting a Keder house ever since they came on the market. Now I have one and the benefits are everything I had hoped for. The next project As you can see it's still a work in progress, at the rear vent end there will be a narrow deck for standing pots outside. I will be installing an old water tank inside (after it's been painted black) to act as a passive solar heat store. You can see we hinged the rear vent rather high....we like it that way though Richard Loader, South Gorley, Hants