One of the requirements for the garage is a comfortable working environment. This includes temperature control. Insulation is usually an important factor, as good insulation prevents heat exchange, keeping the insulated room cooler in the summer and warmer in the winter. There are however some reasons that made me decide against extensive insulation of the garage:
- Insulation works best for rooms that are kept at a constant temperature, e.g. a living room, by constantly heating/cooling to compensate the heat exchange that still takes place. A garage that is unused for several days will still cool down. Hence the benefit of insulation is limited for a garage that is used only several hours a week.
- Insulation takes up space, in a garage that is already quite narrow.
- Insulation costs money.
- Insulation is a possible fire hazard, in the case of EPS/XPS. Fire-resistant insulation material is available, but more expensive.
- Insulation is only effective without ventilation, but lack of ventilation leads to condensation, mould, and rust. A wet car parked in a well-isolated garage will turn brown on the outside and white on the inside within a couple of weeks.
Hence I’ve decided to isolate at most the door. More important is an efficient heater equipped with a powerful fan that can also be used to cool the garage. This way, ventilation is not impaired. Electric heaters with 3kW power are also quite cheap.