ᐅ Is a single router sufficient to cover an entire house?

In our new build, we have a completely separate granny flat upstairs for our son.

Now the question arises whether one router downstairs is enough for our son to use Wi-Fi upstairs as well; if necessary with a repeater. Our installer says it will be difficult because so much concrete and steel is used in new houses. It would be better to have a separate router upstairs.

Other "experts" in the family say that this is all nonsense. The new good routers can handle this easily, even without a repeater. How can you tell if a router is good?

Does anyone have experience in this area?

This will most likely not work due to reinforced concrete in the intermediate ceiling. If it does work, it will not satisfy him in terms of quality.
The required device is an access point that is connected by cable to the same network as the router on the ground floor.

Did you have any network cables installed, at least one running from the lower floor (where the router will be) to the upper floor (where the access point can be placed)?

The classic repeater, which is often sold with devices, rarely satisfies younger users due to significant signal loss. In this case, it makes perfect sense to install an access point connected via a cable.

There are great systems that are easy for beginners to set up (Linksys, eero, etc.). Depending on the size, floor plan, and building materials, it might also be worth investing in a mesh system with 3–4 access points. This costs a few hundred euros and provides a solid setup.

Repeaters are generally pointless. As the previous speaker already mentioned: install an access point connected to a network cable, and everyone is happy.

Heidi1965 schrieb:

In our new build, we have a completely separate granny flat upstairs for our son.

Now the question arises whether one router downstairs is enough and if our son can still use Wi-Fi upstairs.

These two statements contradict each other. If your son uses your internet connection, he is part of your network. By default, there is no separation unless you provide him with a typically limited guest access.

If the lack of separation doesn’t bother you, the standard solution in a new build is a wired LAN connection from your network hub to his. Repeaters are a makeshift solution and can easily be avoided in a new build. Concrete ceilings and underfloor heating usually kill Wi-Fi signals.

By the way, the transmission power of Wi-Fi devices is legally limited. Buying a "good" router only has a limited effect on the range. Especially with 5 GHz, the signal will probably stop at a concrete ceiling anyway...