I found this subject one of
the hardest to get an answer to.
There are few decent books around about keeping budgies and most deal with them as indoor pets only skirting into the idea of keeping them as aviary birds.
Heating? Em... hunt as I might I found next to nothing.
Budgies are hardy birds once acclimatised- but they do not do well in draughts... so your double-glazing and insulation is going to help enormously especially if the doors and windows fit properly.
I have a friend who keeps her budgies (all year round) in an outside flight which has the roof of one end covered with Perspex. Three fence panels for the end and two sides. Her birds have box shelters to dive into to avoid the worst of the winds but no heating at all. I personally wonder how they survive even down here in the sunny south of England...but survive they do.
A local breeder that I know uses a 150W light bulb to extend the daylight hours in winter to enable his birds to feed later after sunset. The large wattage bulb gives out heat but when the light goes off I guess the heat must too. a smaller low wattage bulb stays on most of the night I think.
Another chap- a champion breeder of show birds has his birds fully enclosed all winter... they are outside in the bird-room but there is no outside flight and the windows stay firmly closed. I believe he maintains 10C as a minimum temperature day and night during the breeding season (which is anytime from now up and well into the New Year...seems a daft time to me to breed birds then but it is all to do with next years show calendars apparently).
So... it depends who you ask about heating, where they live and what their birds are used to.
No help so far eh?
What I do:I aim never to have birds breeding over the colder months to avoid the possibility of hens becoming egg bound.
My aviary has inside and outside flights. When it is very cold & windy my birds remain shut inside.
They are shut in each night over winter but allowed to go out during the day.
In winter I do have a thermostatically controlled heater which is usually set 10C but rarely higher. My birds have been happy to go outside when it's snowing - the cold isn't a problem to them - if they don't want to go out they can choose to stay in out of the wind and sheltered - large temperature fluctuations are probably more of a problem than low temperatures (Hot to cold would not be good).
Keeping them draught free especially when they roost is important.
I have tried a tubular heater but found it generally ineffective although it might keep the frost off during the worst of winter nights if there is no draught to suck away the heat.
I use a 13amp plug in thermostat which turns on / off a simple fan heater. Many people would disagree with a fan heater for an aviary preferring electric oil filled radiators (I think these are too slow to heat up personally and slow to cool down if the sun comes out and temperatures rise quickly). Others use convection heaters but I'm more than pleased with my fan heater.
I use one that was made to be used in a greenhouse - a neat little green coloured plastic cased fan heater. It has a thermostat built in - can be used as a cooling fan or as a heater with various settings. This coupled with the plug-in thermostat makes for an efficient and effective safe-guard. I know my birds will not freeze and I won't use too much fuel keeping them comfortable.
If nothing else the heater makes me feel better on a cold winter's night - I don't feel guilty having shut the birds in for the night and come home to central heating.
If my aviary temperature drops as low as 6 or 7 in the worst of the winter I know the birds will not really be bothered...but my aim is to have it around 10C even when it is below freezing outside. The fan heater is not directed at the birds but heat is blown gently across the bird room floor and warmth rises and circulates. The birds are not in the least fussed by the noise of the fan coming on and off even in the night having become accustomed to it. (Mine are pretty laid-back budgies all round).
I hope my long ramble is useful - ask away if there's anything specific that I might be able to help with.
But.... it is a matter of acclimatising your birds, avoiding big temperature swings (bright winter sun can send bird room temperatures rocketing especially if you have glazed windows so take care), keeping birds draught free and dry, well fed and not over crowded helps.
A bit of background heat can be useful... to keep water pots unfrozen and make it more comfortable for the budgie keeper too.
The joys of winter!!
