A Tollcross customer came to us in August with a half-ordered build in two cardboard boxes — a current six-core CPU, 32 GB of RAM, a 320 mm triple-fan graphics card and a mid-tower case. The problem was that the mid-tower’s drive cage sat in exactly the space the graphics card wanted to occupy, and the card was 7 mm too long. He had already fitted the motherboard, found the clash, and come to us to decide whether to return the case or the card. We sent back the case. He had done nothing wrong beyond trusting that a case rated for “up to 330 mm” GPUs would take one — a figure that, on most mid-towers, assumes the drive cage has been removed first.
That is the honest shape of custom builds in small Edinburgh flats. The components aren’t the hard part — the room is. The questions that save people money are almost never about silicon. They’re about where the tower will live, how much noise is acceptable at 10 p.m. in an open-plan living room, whether the top-floor flat gets hot enough in August to throttle a GPU, and whether the ring main in a 1900s tenement will take the load alongside the kettle. The parts list comes after those answers, not before.
Before You Pick Components, Measure the Room
The first thing we ask a customer booking a custom PC build is to measure three things: the width of the space the tower will sit in, the height clearance above it, and the straight-line distance to the nearest power socket. These sound trivial but they decide what case class is realistic. A desk cubby with 220 mm of width rules out a standard mid-tower before we start; a cubby with 450 mm of clearance means a mid-tower is fine but a full-tower will scrape the shelf above. The “compact” cases we end up specifying for most Tollcross flats are between 20 and 25 litres of volume, with ITX or Micro-ATX motherboards, and will take an air-cooled modern CPU and most dual-fan graphics cards.
The power socket distance matters because surge-protected extensions are honest for a PC and monitor but not for a PC, monitor, soundbar and lamp. If the only socket is two metres away and already crowded, we build in a sensible power plan from the start rather than letting it become a daisy chain afterwards. A single six-way surge strip, with the tower on its own outlet to the strip and nothing high-draw sharing it, is the baseline we always leave the build on.
Case Size: Where the Tower Will Actually Live
“Compact” is doing a lot of work in case marketing. In our workshop we treat anything under about 25 litres as true small-form-factor, anything 25-40 litres as compact mid-tower territory, and anything over 40 litres as the full-size cases that mostly don’t belong in a tenement flat. The two decisions that follow from case size are the motherboard form factor (ITX, Micro-ATX or ATX) and the cooler height. We check the cooler clearance against the case’s own spec, not the cooler’s, and we have been burned enough times to measure one in person before we commit.
If the tower is going to sit on top of a desk rather than under it, the case’s visual weight starts to matter — a glass-side full-tower in a bedsit looks like someone parked a server rack next to the sofa. For most of the small-flat builds we scope, a quiet dark-panelled mid-tower on the floor beside the desk reads correctly in the room and leaves the desk clear for monitors and keyboard.
GPU Length Is the Clearance That Catches People Out
The most common assembly failure we see on half-finished builds is a graphics card that doesn’t fit the case with the drive cage still fitted. Modern mid-range cards are 280-330 mm long with the plastic shroud and backplate included; the manufacturer figure on the box is usually the PCB length, which is shorter. Case manufacturers quote “GPU clearance” as the maximum with cages removed, and “GPU clearance with HDD cage installed” as a second, smaller figure that is often 50 mm less. If you miss that distinction you end up where our Tollcross customer did: a working motherboard and a card that won’t sit flat.
The honest fix on a new build is to buy a case that fits the card you actually want, and to buy the exact card length (not the box figure) before you commit. On a build that’s already in boxes, we sometimes salvage it by returning the case and buying one with no drive cage in that lane, which is often cheaper than returning the GPU. Where a swap isn’t available, a dual-fan version of the same card typically shaves 40-60 mm and fits.
Noise in an Open-Plan Flat Is a Design Problem, Not a Fix
Tollcross flats are mostly open-plan or close to it — a living room with a kitchen along one wall, the bedroom through a door that doesn’t close completely, hard floors because carpet is a landlord headache. A PC that sounds fine in a detached garage sounds very loud in a 32 m² flat with no soft furnishings to soak it up. The decisions that make the difference are made at build time, not fixed later with aftermarket fans.
Three things matter: the CPU cooler, the case fans, and the GPU’s fan curve. A good air cooler on a sensibly undervolted modern CPU runs quieter under load than a cheap 240 mm all-in-one on the same chip, and never leaks on the carpet. Three low-RPM 140 mm case fans at the right positions move more air than six 120 mm ones at the same noise, and the GPU’s own fan curve — set once in Afterburner or the manufacturer software — can drop the loudest component in the build by fifteen decibels. We tune those on the bench, because a customer’s living room at 42 dB ambient is a bad place to measure.
Heat in a Top-Floor Tenement, and Why 2026 Summers Changed the Plan
In the first week of August 2026 we diagnosed two overheating builds on the same tenement stair in Tollcross — both top-floor, both over 28°C ambient in the living room by late afternoon, both running GPUs that were throttling after fifteen minutes of a sustained game. Neither owner had a bad build; both had builds that would have been fine three summers ago, in a Scottish summer we no longer reliably get.
The quiet lesson of the last two summers is that custom builds in Edinburgh now need the thermal headroom we used to reserve for London. We budget cooler capacity for a 25°C ambient, not 18°C, which usually means a tier up on the CPU cooler and one extra intake fan compared to the online “sensible build” guides. Where the flat is on the top floor and takes direct sun through the afternoon, we also set the case on an elevated stand (so it draws cooler air from floor level, not warmer air from desk level) and we talk honestly about whether a dust filter is going to need cleaning monthly rather than quarterly.
The 13-Amp Socket Math No One Mentions
A UK ring main delivers 13 A per socket, which is 3 kW at 230 V. A gaming PC under load pulls 400-600 W, a 32-inch monitor pulls 50-80 W, a soundbar pulls 20 W, a laser printer at warm-up pulls 1-1.2 kW, and a kettle pulls 2.5-3 kW. Most Edinburgh flats have a single kitchen ring and a single living ring, and the kettle usually sits on the same ring as the TV wall. We’ve had a customer in a flat near Bruntsfield whose build would reboot every time the kettle came on — not because the PSU was undersized, but because the ring voltage was sagging past the PSU’s minimum under combined load. A 650 W platinum PSU on a surge-protected strip, on a socket not shared with the kettle, solved it.
We size PSUs honestly: 650 W is plenty for a mid-range build, 750 W is sensible for a build with a top-tier GPU and headroom to upgrade, and anything above that is almost always a product of parts-picker sites being paranoid. A quieter, better-regulated 650 W unit from a known brand will outlast a 1000 W marketplace unit twice over, and it won’t argue with the ring main when the kettle goes on.
Where to Spend and Where to Save
The way we split the budget on a small-flat build looks different to a desktop-building guide written for someone with a dedicated office. We spend above the online average on the case, the PSU and the cooler — the parts that make the machine live quietly, safely and for ten years in a small room — and less than average on RGB, drive-count headroom and marketing-grade motherboards. On the silicon side we spec the CPU for the actual workload, not the halo tier; a current six- or eight-core chip handles everything most customers do, and the saving pays for the storage and the monitor.
When We Suggest a Prebuilt or an Upgrade Instead
Not every brief ends with a custom build. If the customer’s current machine is a four- or five-year-old desktop with a healthy motherboard and PSU, the honest answer is often a GPU and SSD hardware upgrade rather than a full rebuild. We’ve written about the real gains of a RAM and SSD upgrade in our upgrade guide, and the pattern on the bench matches — the biggest felt improvement from the smallest spend. If a prebuilt is a better answer, we say so, and we keep our own custom build service and gaming PC upgrades write-up up-to-date for the customers who want a machine tuned to the room they live in.
Bringing a Build Brief to Us
If you’re at the stage of a shortlist, bring us the shortlist and the dimensions of the space it’s going into. We’ll check the clearances against the exact case, confirm the PSU and cooler against the room, and tell you plainly where we’d change the picks and where we think you’re already right. If you’re already in boxes we’ll finish the build on the bench, test it at full load for two hours on the workshop link, and set the fan curves and undervolt before it leaves. Book it in for a custom build consultation in Tollcross, or come to us from Haymarket, Fountainbridge or Bruntsfield — the flats and the constraints are mostly the same from Lauriston Place to Dalry Road, and the plan we scope on the bench holds across the whole central ring.
Last updated: 2 October 2026