Building and block sharing

How to share one internet connection across a building

One good connection, split properly, beats a dozen average ones. Here is the setup, the rules and the traps, in plain English.

No sales pitch and no made-up numbers. Just how shared building internet actually works.

The short version

If you read nothing else, read this.

You need three things: one decent router, per-unit VLANs and fair-share QoS.
VLANs keep each unit's traffic private. Sharing a WiFi password does not.
QoS stops one heavy user hogging the line for everyone else.
Check the plan's terms first. Business plans usually allow sharing, residential plans often do not.
Do not share if the building has a genuinely heavy user or a tenant with compliance needs.

How sharing one connection actually works

There is no magic in it. One fast service comes into the building at a single point, then gets split three ways: routed, separated and rationed. Get all three right and every unit gets fast, private, fair internet off one bill. Skip any one of them and you have built a mess that ends in arguments.

The gear list is short: a router good enough to handle the whole line, a managed switch, and access points wherever the WiFi needs to reach. Nothing exotic. The value is not in the hardware, it is in configuring it properly.

One router does the splitting

A single connection terminates at one router for the whole building. Every unit hangs off that router instead of running its own modem and its own plan. One bill, one point of entry, one thing to maintain.

VLANs keep units separate

A managed switch puts each unit on its own VLAN. Unit 3 cannot see unit 5's laptops, cameras or traffic. Each unit behaves like it has its own private network, because logically it does.

QoS keeps it fair

Fair-share quality of service rules ration the bandwidth. When the line is busy, every unit gets its guaranteed slice. When it is quiet, whoever needs the speed can use the lot.

Where sharing makes sense, and the fine print

Sharing works best when the people sharing already share a roof or a title. One warning before the list: check the terms of the internet plan first. Most business-grade plans are fine with multiple tenancies. Many residential plans are written for a single household, and sharing beyond that can breach the terms. Read the plan, or ask the provider straight out. Do not assume.

Body corporate apartment blocks

The cleanest case. The body corporate holds one account, runs the network as a building utility and recovers the cost through levies.

Granny flats and secondary dwellings

Same title, same owner, one connection. The easiest share there is, and a proper VLAN still beats handing over your house WiFi.

Share houses

One house, one bill, one network. VLANs between housemates are optional, but fair-share QoS will prevent more arguments than a chore roster.

Small commercial blocks

A handful of tenancies over one business-grade line, each on its own VLAN. Usually cheaper per tenant than separate business connections.

Duplexes and dual occupancy

Two dwellings, one line down the middle. Split the cost evenly and keep the two networks properly separate.

Caravan parks and cabins

Many sites, one strong feed, access points across the grounds. The same idea at a larger scale.

What fair actually looks like

Fair is a setting, not a vibe. If nobody configures fairness, the network defaults to a free-for-all, and a free-for-all is always won by whoever downloads hardest. This is what I would set up on any shared building network.

A guaranteed floor

Every unit gets a minimum share it can count on when the line is saturated. Video calls keep working in unit 2 even while unit 6 pulls down a game update.

Burst when it is quiet

Guarantees only bite under load. At 3am one unit can happily use the entire line. Capping everyone all the time just wastes bandwidth the group has already paid for.

The same rules for everyone

No quiet fast lane for whoever runs the network. The config is the agreement. If the group wants a different split, change the config, not the favours.

What it costs, in plain terms

I will not invent dollar figures, because the honest answer is that the spread is wide and it depends on the building. What I can tell you is exactly what drives the cost, so you can judge any quote on its parts.

The connection itself. One business-grade plan replaces many residential ones. This is where the saving lives: one bigger bill divided by everyone usually beats each unit paying alone.
Hardware. A router that can push the full line speed, a managed switch, and an access point wherever WiFi has to reach. Buy it once and the building owns it outright.
Cabling. The biggest variable by far. A new build with conduit is easy. Getting cable through a 1970s double-brick walk-up is not.
Setup. VLANs and QoS get configured once, by someone who knows what they are doing. Set it once, set it right, walk away.
Ongoing ownership. Someone has to own the bill, the firmware updates and the reboot when things go sideways. Decide who before the network goes in, not after.

When not to share

Sharing is not for every building, and pretending otherwise is how these projects fail. I would not share a connection in any of these situations.

A genuinely heavy user. Someone who uploads video all day, runs servers or moves serious data will bump into the fairness rules constantly and resent them. They need their own line.
Compliance requirements. A business with regulatory, security or insurance obligations around its network should not sit on shared infrastructure. It needs a dedicated service with its own public IP.
Zero tolerance for shared fate. One line means one outage takes out the whole building at once. Anyone whose income stops when the internet stops should hold their own backup at minimum.
Nobody will own it. A shared network with no owner rots. If no one in the building will take responsibility for the bill and the gear, do not build it.

Straight answers to the usual questions

These are the questions we get asked every time shared building internet comes up. No hedging, no fine print buried in a PDF.

Is it legal to share internet with neighbours?

Sharing is not illegal, but it can breach the terms of your plan. Residential plans are usually written for a single household at a single premises. Business plans are usually fine with multiple users and tenancies. Within one building on one title, with the right plan, you are on solid ground. Across property boundaries, read the terms and ask the provider before you build anything.

Can other units see my traffic on a shared connection?

Not on a properly built one. Per-unit VLANs keep each unit's devices and traffic logically separate, so unit 3 cannot see unit 5 at all. On a lazy setup, where everyone joins one WiFi network, every device can see every other device. The VLANs are the difference between sharing and exposure.

Won't one heavy user slow everyone else down?

Only if nobody configured fairness. Fair-share QoS guarantees each unit a minimum slice of the line when it is busy, and lets anyone use the spare capacity when it is not. Without QoS the heaviest user wins every time. With it, they cannot.

How fast does the shared connection need to be?

Slower than you think. Not everyone peaks at the same moment, so a building shares far better than a simple per-unit division suggests. Count the units, think about the heaviest realistic evening, and size the plan for that. A network that is still quick at 8pm on a Sunday is sized right.

Who pays the bill and how is it split?

One account holder, one bill, and a written agreement on the split. In a body corporate, run it like any other building utility and recover it through levies. In a share house or duplex, an even split usually works. Whatever you choose, put it in writing before the network goes in.

Can I just give the neighbours my WiFi password instead?

You can, and you should not. There is no separation, so they can see your devices. There is no fairness, so their downloads fight your video calls. And it almost certainly breaches a residential plan's terms. If sharing is worth doing, it is worth doing properly.

Want this set up for your building?

Register your interest and tell us where the building is. When there is enough demand near you, we organise the shared connection and set it up properly.