Planning Your Network When Building a House

There's one kind of networking decision that better hardware can't fix later: the cable routes inside the walls. While the walls are open, adding a run costs almost nothing. After paint, tiling, and fitted cupboards, the same work becomes demolition.

The trouble is that this decision gets made when nobody is thinking about networking. What follows is what to raise with your builder, and the moment to raise it is alongside the electrical work.

Decide the entry point first

Everything starts at one place: where the provider's cable enters the house. That's where the ONT and router will live, and where every other run begins.

What makes that point good:

• Power sockets, ideally two or three, because it will hold an ONT, router, switch, and eventually perhaps a UPS.
• Not damp, not in direct heat. Not behind the fridge, not beside the kitchen, not in an unvented store room.
• Easy to reach, because this equipment needs power-cycling occasionally. A ceiling spot needing a ladder will be awkward at exactly the wrong moment.
• Near the middle of the house if possible, since the router goes there. If not possible, that's fine, provided there's a cable route to the middle.

Positioning is covered in where to put your router, and the equipment that will sit there in modem, router, and ONT.

Where the cables go

A sensible list for an ordinary house, and it needn't be longer:

• The TV area. Televisions, consoles, and set-top boxes all do better on cable, and none of them ever move (connecting a TV to the network).
• The workspace or whichever room is used for work. Video calls and live streaming are where cable versus Wi-Fi shows most clearly.
• One ceiling point at the centre of the house. This is for an access point, the most-forgotten and most valuable run of all.
• One ceiling point upstairs, in a two-storey house. Why, in weak Wi-Fi upstairs.
• Camera points, if you plan to fit any. Wired cameras are far more reliable than Wi-Fi ones, and one cable can carry their power too (PoE).

Four to six considered points are far more useful than a dozen spread evenly out of habit. What matters isn't the count but whether each point is where equipment will actually sit.

Which cable

For a house, Cat 6 is the right stopping point: enough for the speeds of the next many years, and barely more expensive than Cat 5e across a whole house. Cat 6A and above are thicker, stiffer, harder to pull through conduit, and their benefit won't show in an ordinary home. Discussed in choosing LAN cable.

Two things matter more than the cable category:

• Don't share a conduit with mains wiring. Use separate conduit. Network cable running parallel to power cable for several metres picks up interference, and the symptoms are hard to trace years later.
• No sharp bends, no hard pulling. Damage from pulling isn't visible and doesn't show immediately; it appears as a link that's sometimes slow.

The most valuable thing: empty conduit

If you can ask for only one thing, ask for this. Empty conduit from the entry point to the centre of the house and upstairs, with a draw string inside.

Empty conduit means any cable can be pulled later without breaking anything open: cable that doesn't have a standard yet, fibre inside the house, or simply a replacement for a damaged run. While the building is open it costs almost nothing, and its value only shows a decade later.

The draw string matters. Conduit without one often goes unused, because pulling new cable around bends becomes a job in itself.

Where the cables gather

Every run ends in one place, and that place needs preparing rather than becoming a pile on the floor. It needn't be a full rack. A small ventilated wall cabinet is enough for a house, provided:

• Air can move through it. A sealed cabinet cooks the equipment, and heat shortens its life.
• There's a socket inside.
• There's room for a small switch, because the provider's router usually has four ports and they run out (choosing a network switch).

Cabinet and rack options are in choosing a network rack.

Cable still matters with mesh

A common misunderstanding: people install mesh precisely to avoid running cable. Yet the best mesh is one whose nodes are wired. A node linked wirelessly must use the same airtime to receive and relay, so capacity is cut with every hop.

One cabled ceiling point in the middle of a house usually beats three scattered wireless nodes. Compared in mesh versus repeater and access point versus second router.

If the house has a yard or terrace that will be used, consider one run outside as well (outdoor access points).

Building materials decide things too

Two things worth knowing early, because they can't be changed afterwards:

• Reinforced concrete walls and floors weaken signal far more than lightweight block or plasterboard. A multi-storey concrete house almost always needs an access point per floor, and that's a cabling decision, not a hardware one.
• Metallic-coated glass in energy-efficient windows reflects signal. Indoors that usually helps, but it means Wi-Fi won't reach the terrace or yard.

If the house already exists

All of the above still applies during renovation, with one addition: do it alongside work that's already opening things up. Replacing a ceiling is the best chance to run cable to an access point, and new floor tiling is the chance for floor routes.

If cabling is genuinely impossible, the remaining options are in powerline and the alternatives. It works, with caveats worth understanding before buying.

Once it's all installed

Two things worth doing before the builder leaves, because both get much harder afterwards:

• Test every LAN point individually with a laptop, and confirm each one genuinely works. A miswired point behind a wall only surfaces years later, when there's nobody left to ask. The full checklist is in testing your network after installation.
• Photograph the cable routes before the walls close, and keep them with your network notes. Those photos are the only map that will ever exist (documenting your own network).

Frequently asked questions