Wiring a New House for Internet: What to Run Before Drywall

The electrician finishes on a Tuesday and the drywall crew is booked for Friday. For those three days every wall in the house is a hallway: a cable can go from anywhere to anywhere in the time it takes to walk it. After Friday the same cable costs a hole, a patch, two coats of paint and a Saturday. That arithmetic is why people who fully intended to wire the house end up buying a mesh system instead.

Almost everything else on this site can be revisited. A bill can be disputed months later. A contract clause can be read after it has been signed. This one cannot. So the question is narrow and worth answering precisely: what actually has to be in the walls, and what can wait.

One hundred metres is the only distance that constrains anything

Balanced twisted-pair Ethernet is specified around a 100 m channel, and every speed grade a house is likely to want lives inside it.

The amendment that first defined 10 Gb/s over copper, IEEE 802.3an-2006, which IEEE SA now lists as superseded, is summarised there as specifying "a LAN interconnect for up to 100 m of balanced twisted-pair structured cabling systems." The intermediate speeds are explicit about which cable gets them there. The objectives IEEE 802.3 approved on 12 March 2015 for the work that became 2.5GBASE-T and 5GBASE-T call for a 2.5 Gb/s PHY running "up to at least 100m on four-pair Class D (Cat5e)" and a 5 Gb/s PHY running "up to at least 100m on four-pair Class E (Cat6)."

Now measure the house. A run from a central closet to the far bedroom of a 250 square metre home, taken up one wall, across a joist bay, down again, with service loops at both ends, lands somewhere near 30 to 40 m. Two storeys plus a detached garage might push a single run past 60. Nothing in an ordinary single-family house approaches 100 m unless the building is very large or the cable takes a genuinely silly route.

So distance is not the constraint. The number is still worth knowing, because it says the opposite of what most people assume going in: there is no need to agonise over category for reach. What will actually go wrong is running too few cables to too few places.

One rule does bind, and it is structural. Every run goes from its outlet back to one central point, on its own. No splicing, no daisy-chaining one room to the next, no single cable feeding two jacks. Ethernet is a star, and a run that serves two rooms serves neither.

Which cable to buy, and what the spec sheet costs you on the day

Categories 5e, 6 and 6A map onto ISO classes D, E and EA. In a house the practical difference between them is narrow and it is entirely about 10 Gb/s.

The reach target IEEE 802.3's 10GBASE-T study group set for itself, in the objectives it published in September 2003, was "at least 100 m on four-pair Class F balanced copper cabling" and "at least 55 m to 100 m on four-pair Class E balanced copper cabling." Class E is Cat6. That span, 55 to 100, is the entire reason Category 6A exists: the augmented grade is the one specified to carry 10GBASE-T the full distance. Siemon's Category 6A F/UTP spec sheet states it plainly, describing a channel "capable of supporting 10GBASE-T operation over 100-metre, 4-connector topologies."

Set that beside the house measurement above and the decision gets less dramatic. At 35 m, Cat6 is inside the 10 Gb/s window already. Cat6A buys headroom in a building this size, not a capability you otherwise lack.

What Cat6A costs is handling, and the numbers for that are printed on the sheet for the reel you actually buy rather than attached to the category. That Siemon F/UTP cable lists a nominal outside diameter of 6.99 mm, a minimum bend radius of 27 mm, and a maximum pulling tension of 110 N, which the sheet also gives as 25 lbf. Those are one product's figures. Shielded constructions sit at the thick end of the category, unshielded ones are slimmer, and the numbers move between manufacturers, so the sheet that governs your pull is the one for the box in front of you. Tension is the figure to treat as a hard limit rather than a caution: exceed it and the twist comes out of the pairs. The link does not break. It quietly stops delivering the performance you paid for, and nothing about the wall plate will ever tell you. Diameter decides the rest of the day, because it eats conduit fill and makes a ninety-degree turn inside a stud bay harder than it looks on paper.

Two more things to read off the box rather than the product listing. The conductor should be solid copper, 23 AWG in the Siemon sheet's case, not copper-clad aluminium. And the jacket carries a UL type marking whose suffix states where the cable is allowed to go: UL's wire and cable application guide explains that "Suffixes to the Type designation identify the use as defined in the appropriate NEC articles," and lists them: -P for plenum, -R for riser, no suffix or -G for general purpose, -X for limited residential use. The guide ties that scheme to cables covered under NEC Articles 722, 725, 760, 770, 800, 805, 820 and 830, and it does not tell you which of those governs a particular wall. Which suffix your walls require, how the cable has to be supported, and how far it must stay from electrical cable are questions for the local building department. Ask them before the cable is on site rather than during the rough-in inspection.

The run list comes from how the house is used, not from the floor plan

Start at the centre. Pick one location for the panel: near where the service enters the building, with an electrical outlet, with air around it, and not inside a sealed closet where a switch and a gateway will slowly cook. The provider's equipment is landing near the entry anyway, because the boundary of their work sits about twelve inches outside the wall and the technician will not extend it for nothing. That boundary, and who pays when the drop is missing, is the subject of a separate piece on installation day, and it is worth reading before the panel location is fixed, since a panel on the wrong side of the house becomes one long ugly run forever.

Then the list itself. Two Cat6 or Cat6A runs to every room that could plausibly hold a desk or a television. Two, not one, and not for bandwidth: a single run with one damaged pair is a room with no wired connection, and the second cable pulled alongside the first costs only the cable.

One run to the middle of the ceiling on each floor, for an access point. This is the item most often skipped and the one that repays hardest, because an access point in a ceiling is an access point in the middle of the space instead of behind a television. Those runs need no outlet beside them. The objectives for IEEE 802.3bt, four-pair Power over Ethernet, require support for "a minimum of 49 Watts at the PD PI" over channels whose DC loop resistance is no greater than 25 ohms, including "Category 5e or better cable and components as specified in ANSI/TIA-568-C.2." Forty-nine watts at the device covers an ordinary ceiling access point with room left over, though the multi-radio models draw enough that the access point's own PoE class is worth reading before the switch is bought. One cable carries the data and the power, and the ceiling stays clean.

Then the ones people wish they had. A run to the front door and to whichever exterior corner a camera would go. One to the garage. One terminated in the attic and one in the crawl space, coiled and labelled, for whatever has not been thought of yet.

Coax gets a shorter list but not an empty one. One run from the entry point to the panel and one to the main television wall, even with no intention of buying television service. Coax is how a roof antenna gets indoors, it is how some fixed wireless installations bring a signal down from a window or eave, and it is the medium the next section is about.

And one piece of conduit. A single length of flexible tubing from the panel up to the attic, and another down to the crawl space, is the cheapest thing on this list. It is what lets fibre, or a cable that does not exist yet, be pulled into a finished building without cutting it open.

The coax already in the walls, and MoCA's three conditions

In an existing house the equivalent question is whether the coax is usable. The answer is usually yes, with conditions.

MoCA puts an Ethernet network onto coaxial cable. The current home specification, MoCA Home 2.5, is listed by the alliance at 2.5 Gbps MAC throughput, under 2.5 ms average one-way latency, across 400 to 1675 MHz of usable spectrum. The release announcing the specification in April 2016 puts it at "up to 2.5 Gbps actual data rates" over up to 16 nodes and says it is "backward interoperable with MoCA 2.0 and MoCA 1.1." I read both pages on 27 September 2026.

Three conditions decide whether that works in a given building.

The coax path has to be continuous. MoCA is not broadcast; two adapters have to reach each other over copper. If the bedroom outlet was capped behind a wall plate and never connected to the splitter, no adapter repairs that. This is the condition you cannot buy your way out of, and it is the one to test before spending anything.

Every splitter in the path has to pass the band. MoCA 2.5 reaches up to 1675 MHz. A splitter whose printed bandwidth stops at 1000 MHz is not specified to pass any of the spectrum above that point, and what it actually does up there is not something the label will tell you. Splitters marked to 1675 MHz exist for exactly this reason. Read what is stamped on the ones already in the house before replacing them.

A filter at the point of entry does two jobs, which is why it is not a downgrade. A filter sounds like something that takes capability away, and this one adds it. Take one published example, the data sheet for PPC's SNLP-1G, for the shape of the type: insertion loss no worse than -2.5 dB across 5 to 1002 MHz, and rejection of at least 35 dB across 1125 to 1525 MHz. The pass band is your television and internet service, which is why the filter costs you nothing. The rejection band is the stretch of coax spectrum it is there to keep inside the building. PPC describes the purpose as physically isolating the home "to avoid interference from near-by MoCA users, such as a neighbor," and says the filter "acts as a reflector to minimize MoCA signal loss in the home." It keeps your network off the street and bounces your own signal back inside, which is why it belongs at the ground block, ahead of the first splitter, rather than somewhere in the middle of the house. It also has the same readable limit the splitters do: that sheet states a bandwidth of 5 to 1525 MHz, while MoCA's usable spectrum runs to 1675 MHz, so the numbers on whichever filter you buy are worth reading rather than assuming.

Before buying one, look at what is there. If a filter is already in line at the entry, someone put it there deliberately, and that may mean the coax is carrying a MoCA network belonging to the provider's own equipment. A second filter is not the fix for anything.

Check adapters against the alliance's certified products list rather than the box copy, because certification is granted per model and the list names models.

What MoCA is not is a substitute for the run you did not make. It is an excellent backhaul between a gateway and an access point at the far end of a house. It will not give a desk the symmetric multi-gigabit link that a Cat6A cable to that desk would.

Whose cable is it, once it is in the wall

There is a legal layer under the coax question, and it decides whether the wiring is still there after you change providers.

The FCC defines cable home wiring at 47 CFR 76.5(ll) as "the internal wiring contained within the premises of a subscriber which begins at the demarcation point," and says it "includes passive splitters on the subscriber's side of the demarcation point, but does not include any active elements such as amplifiers, converter or decoder boxes, or remote control units." Paragraph (mm) puts that demarcation point twelve inches outside the wall, the same line the installer will not cross. So the definition is a boundary plus a parts list: the coax on your side and the passive splitters on it are cable home wiring, and the amplifier hanging off it is not. I pulled Part 76 from the eCFR versioner API on 27 September 2026, at the 22 September 2026 issue date for Title 47, which the API reported as up to date as of 24 September.

What follows from that matters on the day you cancel. Under 47 CFR 76.802, on voluntary termination in a single-unit installation, a cable operator "shall not remove the cable home wiring unless it gives the subscriber the opportunity to purchase the wiring at the replacement cost, and the subscriber declines." If the subscriber declines, the operator has seven days to take it out, and after that must "make no subsequent attempt to remove it or to restrict its use." The price is defined as well: replacement cost per foot times the length on your side of the demarcation point, plus the replacement cost of the passive splitters. And the rule requires that you be told during the initial call, including "what the per-foot replacement cost and total charge for the wiring would be."

None of that is abstract if you are about to switch and the walls contain coax somebody else paid to install. The rule puts the offer on the operator during that first call rather than on you to request it, but the rule is the only thing that puts it there, which is one more reason to run that call the way this site runs equipment return and the final bill, with the questions written down before dialling. Section 76.801 limits the entire subpart to "that cable home wiring installed by the cable system operator or its contractor," and says its provisions "do not apply where the cable home wiring belongs to the subscriber." Coax you paid to have pulled before the drywall went up sits outside all of this from the beginning, which is a quiet argument for running your own.

Renting, where the wall is not yours to open

Nearly all of the above assumes a wall you are allowed to cut. Remove that and the list shortens, but it does not empty.

MoCA is the first thing to try, because the coax is already installed and nothing is altered by plugging an adapter into an outlet. The three conditions above apply unchanged, and the splitter question is more likely to bite in a rental, because nobody has touched the entry in a decade.

After that it is all surface work. Flat Cat6 runs under carpet trim and door thresholds. Surface raceway follows a baseboard, takes paint, and disappears. An access point sits high on a bookshelf instead of in a ceiling. None of this is elegant and all of it comes back up when you leave, which is the entire point.

What needs permission is anything that leaves a mark: a hole through an exterior wall, a mounted enclosure, a cable stapled through a door frame. Ask in writing, name the specific work, keep the reply. That is the same discipline as getting a landlord's consent in writing before an installation appointment, and for the same reason: the person who will have to undo the work is the one who gets asked about it.

One thing in an apartment building is genuinely not your decision. The FCC's cable inside wiring rules define home run wiring, at 47 CFR 76.800(d), as "the wiring from the demarcation point to the point at which the MVPD's wiring becomes devoted to an individual subscriber or individual loop," and section 76.804 sets out how ownership of it is resolved when a building owner ends a provider's access. Those procedures run between the provider and the building owner. A tenant is not a party to them, and a building manager who says the wiring is spoken for may be describing that arrangement accurately.

Fifteen minutes with a label maker beats a rewire

The part of this job that decides whether any of it is usable in five years happens after the cable is pulled and before the walls close.

Label both ends of every run with the room name rather than a number. "Office north wall" survives a change of owner; "7" does not. Terminate everything at the panel end into a patch panel, or at minimum into keystone jacks on a mounted plate, so the runs are not a bundle of bare cable ends in a closet. Then test each one end to end while the walls are still open, because a pair crushed by a staple is a ten-minute fix today and a drywall repair in March.

Last, photograph every wall. Stand in each room and take a picture of each stud bay with the cable visible, ideally with a tape measure in frame against a corner or a door opening. Those photographs are how someone finds the cable behind the plasterboard in 2031, and they are how you avoid putting a screw through it when you hang a shelf next month. Keep them with the run list and a photo of the panel, and mail the folder to yourself so it outlives the phone.

If the walls are already closed and the wired outlets are not where you need them, the diagnosis comes before the hardware: work out whether the problem is the wireless leg or the line itself before buying a single adapter, because a MoCA bridge solves one of those and does nothing for the other.

The drywall goes up on Friday either way. The difference between a house that is wired and a house that merely has wiring in it is about an hour of labelling and one folder of photographs, and both of those are free.