In the past, I would always leave dough to rise in the airing cupboard as the boiler would keep it at a fairly constant, warm, temperature. However these days, the airing cupboard often seems colder than other parts of the house! I've also tried putting in in front of a heater, but Is there an alternative, like having the oven on at a low temp. that would allow the dough to raise without inadvertently cooking it?
An airing cupboard is usually a good place to leave dough to rise but dough can rise in most places (you can even leave it to rise in the refrigerator overnight) it will just take slightly longer at a lower temperature. A warm kitchen worktop, sunny windowsill or somewhere close to a radiator often works.
You can also leave dough to rise in an oven but you do need to be very careful and also have an oven that can deal with lower temperatures. When you are mixing the dough preheat the oven to 50c (and no more than 60c). Once you have kneaded the dough and transferred it to a lightly greased bowl then turn off the oven, cover the dough with a clean, damp tea towel (dish towel) and put the bowl of dough into the switched off oven. Leave the door slightly ajar for the first 10 minutes then close the door and let the dough rise for another 20 minutes. With the instant/quick acting yeast you may find that the dough has already doubled in size, but if not check that the tea towel has not become too dry (you may need to re-dampen it) and leave for another 15-30 minutes. For most doughs 1 hour should be enough for it to riase properly, if using this method.