Ahhhh thankyou, i just worry about them getting cold. I feel guilty sitting inside in front of an open fire whilst they are outside in the cold. I think because the house is big and i only have 4 little girls. Someone said to pack the rest of the house with straw bails and that would keep it warmer. Thanks for the advice from HF. do you mean to have 4 perches running across instead of 1 i didnt really understand sorry.
Chickens would naturally roost in trees like my legbars here,
Notice they tend to huddle up into a tight scrum for warmth. they don't string out along a single branch.
This is an idea type of perch so that they can huddle up easily.
Also they need ventillation but not draughts so make sure ventillation is above head height and baffled so no direct wind can blow in.
Windows - there shouldn't be any, birds don't need them and they leak heat so block them off with internal shutters. If there's a large access door a curtain of heavy duty polythene will help to reduce draughts. Ensure the roof and walls are completely water proof and draught proof. Have available a large tarpaulin to use in an emergency with ropes and bungees to hold it down.
You can rub vaseline on their combs and wattles if they are large otherwise don't bother.
4 birds in a large airy space aren't going to be able to warm their environment much and so retain heat so bales of straw might work much better if they reduced head room too otherwise any generated heat will just be lost through convection. I'm not sure that 4 birds in a large shed would actually have much heating effect on the air round about them anyway. I think a better use of straw might be to create a dry fluffy litter they can bed down in.
Their feathers will provide by far the most effective insulation so keeping the interior clean, dry and draught free should be the priority. Do that and I very much doubt they will need anything else.
Good nutrition is the other requirement aso make sure they have a full crop before they roost and a couple of handfuls of mixed poultry corn in an evening will do this. There's no need for water or feed in the house and particularly with water there's a risk of spillage which is a really bad thing.
In snow have some pallets available to act as dry snow free walk ways so they aren't wading through snow. Cut in half length ways is best but check they won't fall apart if you do. Some need to be modified to avoid this.