It's the 2020s. Suppose we fantasize about a future in which some or all houses are built to accommodate a "cycling garage". What are the main criteria that would be needed for this to work in practice?
I live in a house that's not primarily designed for cycling. If I ever become very rich, I already know what kind of criteria I have for designing a house built for cycling.
The house must have its entrance at ground level. No stairs. This means I can roll any bike inside my house without raising it with my hands. Makes also easier to replace refrigerators and washing machines (provided they are in the ground floor if the house has multiple floors), since you can roll them directly in with a hand truck. However, usually I probably would prefer just working on the bikes in the garage, but it's useful to be able to push the bike in to the main house as well.
The house must have a garage specially designed for cycling. This means the garage has its own ground source heat pump based heating system that heats it to a temperature far lower than the house itself. The garage must also be well insulated. The combination of being well insulated and having a separate ground source heat pump heating system means the heating energy consumption of the garage is very small. The purpose of the heating is to keep it above freezing for the entirety of the year. It's not to keep the temperature comfortably warm like 20C inside the house around the year. Since the temperature in the garage is about 5C or so even in the winter, it means electric scooter and electric bike batteries can be charged there. The garage would be designed so that the house is resellable to a non-cyclist, so it would have enough space for actually parking a car. However, for the cyclist, the car would obviously be parked elsewhere, so the house must have a parking place outdoors with roof over it (the roof prevents ice from forming in the windshield during winter, because it prevents the windshield losing its heat by radiating it into the cold space during non-cloudy nights).
Because opening an entire garage car door for just pushing one bike inside would be ridiculous, the garage should have a side entrance, a normal door with the same key as the house, at ground level, so that bikes can be pushed in through a normal door and don't require opening the garage car door.
I think in the space one car takes, a huge number of bikes can be parked, so the garage doesn't even have to be very big.
Also, for guests that prefer using a bike, there should be places where such bikes can be permanently locked outdoors. These are best made using inverse "U" shaped arches of tubes made from hard steel, that can lock a rear tire into them with a U lock using this locking strategy by Sheldon Brown.