Triple glazing alone is a problem. Especially in retrofit newly renovated homes based on older 2 x 4 timber frame construction. The problem isn't directed at the cost of the glazing but rather, the issue of weight and the ability of 2 x 4 timber framing taking the extra weight. Triple glazing is 1/3 heavier in weight than double glazing. When you look at large bay windows with double side window openings, the weight must be factored and extra strengthening of the 2x4 timber wall framing must be considered.Even in Chicago where it gets disturbingly cold (the kind of cold where engines stop working and it's waaaay too cold to snow - the top 3 feet of the snowdrifts just freeze pretty much solid), triple glazing just isn't heard of. I still say it's overkill.
In terms of insulation, windows are the weakest point in the wall. Anotherwords, no amount of high tech glass will be as good as an insulated wall. So the only real reason for having windows is for natural daylight and heat from the sun. In NZ, passive heating from the sun is very important. In N. America, heating from the sun is taken with little consideration which is why houses can be built close together and orientation of the house is based on street view rather than on sun view.