Can't get orchids to reflower

[StormOrchid]

I've had orchids for 3 years now, having bought several from the supermarket over the years so I've now got about 6 of them (having thrown out 2 last year). I seem to be an utter failure at getting them to thrive I have NEVER managed to get any of them to reflower! The leaves always seem to look green and glossy, I run water through them once a week and let them drain (so never sitting in water). I have them in numerous places round the house (windowsils (pushed back as I have deep recesses) / shelves etc.). They seem to get little buds bits on them but nothing ever becomes of them, they just shrivel up. I've cut ones right down and they've grown new stems but same thing happens. I've tried giving them regular orchid fertiliser (the kind that slowly drips in) but nothing seems to work.

Our house is quite cold generally (draughty old house on top of a hill in NE Scotland, you get the picture!). Could this be the simple issue that our house is too cold for orchids?

Any help would be great, I love orchids when they're in bloom so its driving me nuts that I cannot help them thrive!