Open-Plan House Wi-Fi: Why Coverage Still Fails

Open plan is supposed to be the easy case. Fewer walls, fewer obstacles, fewer dead zones. Then the far end of the kitchen-dining space drops video calls, the glass extension gets one bar, and the tablet on the island loses the recipe.

Knocking walls out does not remove obstacles. It removes the cheap ones and leaves every expensive one where it was — plus a few that exist only because the wall is gone.

No walls does not mean no dead zones#

A drywall partition costs a 5 GHz signal 3 to 6 dB. That is the wall you deleted. Now count what open plan put in its place. To take a wall out you have to hold the floor above up, so you get a steel beam. To make the space bright you glaze one whole end of it. To make a kitchen work in a room people sit in, you bury the appliances in an island and a run of full-height cabinets. And with the walls gone, you heat the floor.

Every figure there is a rule of thumb, not a reading from your house; the full material list is in signal loss by building material. None of them is a wall you could point to on a floor plan. The obstacle is in the ceiling, in the floor, or wearing a cabinet door.

Plain distance in a 45-foot room#

Before any of that, there is distance. Doubling the distance in open air costs about 6 dB, so a clear indoor 5 GHz path costs roughly 20 to 25 dB over the first 40 feet. Start at -30 dBm a few feet from the router and the far end of a 45-foot kitchen-living-dining run reads somewhere around -50 to -58 dBm on a genuinely clear path — comfortable in itself, but well over half the budget between the router and the -67 dBm floor has gone on air alone. Add one appliance shadow or a pane of coated glass and the same spot lands between -70 and -85 dBm.

So the basics matter more here, not less. Put the router in the middle of the space you use, not at the end with the media wall — this is the one layout that lets you be genuinely central, and most people give that up to hide it behind the TV. Get it above about 5 feet, where furniture and the kitchen island stop mattering, and under a vaulted ceiling keep the antennas vertical rather than throwing energy into empty air. The reasoning is in the router placement guide.

The steel beam and the floor build-up#

The beam nobody thinks about#

The wall you removed was replaced by a steel beam, or an engineered wood beam with a steel flitch plate through it. Either way there is a continuous metal plane in your ceiling, along the exact line where the old wall was.

Treat metal as opaque rather than lossy. But the beam is only 8 to 14 inches deep and sits at the top of the room, so its shadow is directional, not total. High-mounted gear suffers most: a router on a tall bookcase, or a ceiling-mounted access point, sits in the beam's plane and covers one side of the old wall line better than the other. Drop it to head height and the signal passes underneath. Diagonal paths to the floor above cross the beam line too — if exactly one upstairs bedroom is bad and sits above the old wall, you have found your cause.

Heated floors and what is under them#

Underfloor heating is resistance wire in a thin concrete topping, or water pipes clipped to insulation board — and that board is usually foil-faced. The foil is the problem, not the heat: treat a foil-backed heated floor as near-opaque downward, 20 to 30 dB or more.

You rarely notice it on the open-plan level itself. You notice it in the basement or garage below, which loses signal the moment the new floor goes in. Plan that lower level as if the stairs were its only connection upward.

Glass is the most convincing dead zone in the house#

You can see through glass, so you assume the signal does too. Modern glass is not a window for Wi-Fi.

Low-emissivity glazing carries a microscopically thin metallic oxide coating on one internal surface. It is invisible, standard in new windows, near-universal in glass additions, folding patio doors and skylights, and it costs 10 to 25 dB at 5 GHz. Plain single glazing in an old sash window costs 2 to 6 dB — which is why the drafty part of the house often has better Wi-Fi than the new part.

So the glass extension is often the worst room in the house: it looks the most open and is the most sealed. Signal cannot enter through the skylight or the glazed walls — it has to arrive through the structural opening between the old house and the new. Aim at that opening, not at the glass. The patio gets nothing either: closed folding doors are a metal-coated barrier plus aluminum mullions, and coverage outside usually dies within a few feet of them. That is backyard and patio Wi-Fi, a separate problem.

The kitchen island is a metal wall at counter height#

An island today holds an induction cooktop, a dishwasher, a wine fridge, sometimes a steel sink cabinet and an instant-hot-water tank. Every one is a metal box, and together they form a barrier 6 to 10 feet long, from about 2 feet to 3.5 feet above the floor, in the middle of the room. It behaves like a low wall you cannot see. Devices on it suffer most — the tablet propped against the cooktop, the smart speaker, the countertop hub — and seated devices on the dining side lose more than you would expect in a room with no walls. Get the router or extender above about 5 feet and the island stops mattering for most paths.

The full-height run is worse. A built-in refrigerator beside a wall-oven stack is a floor-to-ceiling metal wall 4 to 6 feet wide, and it is almost always on the wall where you wanted the extender. Treat it as a metal panel — 20 to 30 dB or more — and route around it rather than through it. The 2.4 GHz side of kitchen trouble — microwave interference, and why the smart oven drops out at dinner time — belongs to the kitchen dead zone.

Where the extender goes in an open-plan home#

The great room itself is rarely the dead zone. What fails is the perimeter: the utility room, the garage, the office behind the one wall you kept, and the glass extension. Aim at those.

1. Move the router central and high first, and live with it for a full day. It costs nothing and it is the step most people skip.
2. Walk the failure with a live video call and note where it breaks. At the old wall line means steel. A few feet past the glazing means the coating. Only at counter height means the island. Downstairs only means the floor.
3. Place the extender inside the aperture, not behind the obstacle. For the glass extension that is the outlet just inside the structural opening; for the utility room or garage, the outlet on the great-room side of the retained wall.
4. Keep its link back to the router clear of the beam line and the island. Height solves both — a shelf beats a baseboard outlet by 5 to 8 dB here.
5. Confirm it still hears the router well, at the last position where the router reads about -60 to -67 dBm. Further out and it rebroadcasts a marginal signal at full strength, which is worse than nothing.
6. Test in the target room during the activity that annoyed you, not next to the extender.

When no outlet is the answer#

• The great room is already weak 20 feet from the router. That is a router problem; repeating it copies a bad signal further.
• The dead zone is the patio with the doors shut. An indoor extender sits behind the same coating. You need a unit outside the glass line or a wired outdoor access point.
• The target sits behind a full-height appliance run with no path around it. Run a cable.
• Devices cling to the router as you cross the room. That is roaming, not coverage, and a second broadcast point with a different name makes it worse — see why Wi-Fi drops when you walk around.
• Over roughly 2,500 square feet with a glazed extension. One extender will not carry it; plan two or three nodes with the mesh node placement rules.

Planning it on a floor plan first#

An open plan is the fastest floor plan you will ever draw — one big shape, a couple of retained walls, a glazed end, done in a minute. The materials are the slow part, and here they are the entire answer. Range Up has no material for coated glass or stainless steel, but it has the number underneath both: pick the material preset closest to the build, raise the Wall loss value until it describes the glazed end and the appliance run rather than the studwork you knocked out, and push Floor loss up for the foil under the heated floor. Do that and the predicted map stops flattering the room the way your eyes do. Put the router on its real spot and you can finally see the thing an open plan hides: coverage that fails on a line rather than at a wall.

Then mark the extension, or the office behind the wall you kept, and let the app weigh the outlets that could serve it and set the resulting map against the one you have now. It models your drawing, not your live network — nothing scanned, nothing measured, no router login. Expect a flat result more often than in a walled house: if the best available position gains the extension 3 dB, the coating is the obstacle, no indoor outlet beats it, and the honest answer is a cable through the structural opening. Sketch the great room first; the rules for where a second radio belongs explain what to do with the answer.