Before the upgrades
Built in 1996, I knew there was a lot of modernisation required when I moved into my new apartment. Scotland can have harsh weather, and building standards have come a long way since the mid-90's, so while the apartment was structurally sound, its energy efficiency was poor. The insulation was basic, the heating system was outdated, and there were clear areas where energy was being wasted. I saw this as an opportunity — not just to improve comfort and efficiency, but to experiment with new ideas and DIY solutions.
The apartment is a semi-detached, steel-framed building, with an outer layer of red brickwork and an insulated steel roof. It has about 500mm of sub-floor space, divided into three sections by steel I-beams, and 200mm of space between the ceiling and the roof, similarly split into three by steel I-beams. These I-beams caused considerable head-aches. Each room has french doors.
The two electrical panels are divided into three systems: domestic, 24-hour heating, and off-peak heating. The Radio Teleswitch signal, which controls the off-peak supply, was scheduled to be switched off nationwide nine months after I moved in, with no planned replacement for the building. This meant I'd be losing the off-peak supply I relied on for heating and hot water.
With no gas in the building, electricity was the only option, and, at some point, the previous owner replaced the original storage heaters with panel heaters. Each panel heater was installed next to a pair of single sockets — one marked with a green dot, the other with a red dot. If the off-peak supply was active, the heater could be plugged into the green-dotted socket to make use of the lower energy rate. Otherwise, it had to be manually unplugged and switched to the red-dotted socket, which charged the full energy rate. If the heater was plugged into the wrong socket, either the room is cold or the opportunity of cheap energy is missed. This, despite the livingroom being unused over the winter months, led to heating bills of around £1,500 per month.
The 210 litre tank has two 1.5kW immersion heaters: the lower of the two is connected to the off-peak supply, with the upper immersion connected to the 24-hour supply. Under normal water usage, the bottom immersion turns on when the off-peak supply is available to heat the entire tank. If, during the day, the hot water has been used up, the upper immersion can be manually activated to quickly heat the top half of the tank.
The designed ventilation is passive, with trickle vents on each set of french doors, supplemented by uncontrolled air leakage from aging hinges and poor initial build quality.