Wi-Fi in new builds: why modern homes block the signal
A brand new house, perfect insulation, and Wi-Fi that stops at the second wall. The materials that keep heat in are the same ones that keep radio out.
In this guide
People expect an old house with thick stone walls to be hard on Wi-Fi. What surprises them is a brand new home, built to the latest energy standards, where the signal barely leaves the room it starts in. Modern construction is full of materials chosen for insulation, and several of them are excellent at stopping radio.
What's in a modern home
- Foil-backed insulation. Boards and membranes with a reflective aluminum layer, in walls, ceilings and roofs. For Wi-Fi it behaves like a thin metal screen.
- Underfloor heating. Pipes or heating mats in the floor add a dense, often metallic layer between levels.
- Energy-efficient glazing. Double and triple glazing with a metal oxide coating keeps heat in and blocks a lot of signal, which is why gardens and balconies suffer. See Wi-Fi in the garden.
- Metal stud walls. Plasterboard on steel studs is common in newer construction. The board is transparent to Wi-Fi; the regular metal framing behind it is not.
- Reinforced concrete floors and cores, and fire-rated separating walls in apartments and terraced houses.
What this means in practice
Expect shorter range per unit than the numbers on a router box suggest, and expect the fall-off to be abrupt: strong in one room, poor in the next. The good news is that the same construction often gives you something else: pre-installed conduits, network sockets, or at least a service riser you can pull a cable through.
The right plan for a new home
- Wire what you can. New builds are the easiest homes to run cables in, especially if you're still renovating. An access point on each floor, connected by Ethernet, beats every wireless arrangement. See wired backhaul.
- Put the main unit centrally, not next to the incoming line in a corner or a utility cupboard. See internet line in the wrong corner.
- Don't count on signal crossing the building core. Stairwells and door openings are your friends; the insulated floors are not.
- Check the attic conversion separately, if you have one; it's usually the most insulated part of the house. See Wi-Fi in the attic.
Talk to your builder, if you still can
If the walls are open, ask for Ethernet to two or three rooms, and a socket near the center of each floor. It costs very little during construction and saves every workaround later.
Measure, because assumptions fail here
New homes surprise people in both directions: some rooms are fine through two walls, others are dead one room away, depending on where the foil and the metal are. WiFi Heatmap maps what your particular building actually does, which is the only way to know. See also Wi-Fi and walls.