But the Passivhaus Trust – for which Baeli is a non-executive director – acknowledges retrofitting your home to this standard is “expensive”.
The total cost of the work Baeli carried out on her house was around £80,000, not including any additional costs for architectural work.
The most expensive purchase, she calculates, were the windows at £30,000, while one of the cheapest measures was making the whole house airtight, which cost £5,000.
Baeli says, like most people, she could not fund everything at once and decided to carry out the work in stages over ten years to spread the cost.
Although the house does prevent heat entering the home, it does need cooler air to start with.
As well as closing the windows and curtains during the day, Baeli says you need to ensure that “the sun doesn’t hit the glass and create the glasshouse effect – to stop your home from overheating”.
Outside in her garden she shows us dust sheets which have been hung up to cover the windows.
But if outdoor temperatures do not fall at night, as happened once during the June heatwave this summer, Baeli’s house can remain hot. On that June evening, the nighttime temperatures was 27C so the house temperature remained at 27C, the highest Baeli has ever recorded in her home.
If such tropical nights occur again in the future, she says she might need to use air conditioning for a limited time to cool the house and then the Passivhaus measures can maintain that temperature.
