Forums DIY Ground Source Heat Pumps Reply To: Ground Source Heat Pumps October 25, 2018 at 2:46 pm #449 Kez 7 Posts In the short term if you have a tent you could put it up in the children’s room over the coldest weeks. Gives them some cosy space. Or bunk beds with curtains. I’ve no idea about efficency, but all the people I’ve met who live in houses like that have an aga or similar and mostly live in the kitchen in the winter rather than trying to heat the entire house. As mentioned above curtains are important, over doors as well as windows.