In-house server room or datacenter: what to do with your servers in 2026?
Below roughly ten servers, the dominant cost is no longer the hardware: it is the environment around it.
The arithmetic that changes at small scale
An in-house server room does not cost the price of its servers. It costs the price of everything that has to be installed around them so they keep running: cold air, power that does not stop, a link to the outside world, and someone who answers when one of the three fails.
Those items are close to fixed. Room air conditioning, a UPS, a service contract and an on-call rota cost about the same whether you host three servers or thirty. That non-linearity is what makes an in-house server room hard to justify below roughly ten machines: you are paying for infrastructure sized for a requirement you do not have.
A datacenter, by contrast, shares exactly those items across its customers. What you buy by moving there is not floor space — your lease already bills you for that — it is no longer having to watch the air conditioning.
The six dependencies of an in-house server room
Each one is a contract to sign, and each one is a point of failure.
Dedicated air conditioning
A service contract, periodic visits — typically twice a year — and temperature monitoring.
UPS units
An initial purchase, then battery replacement every 3 to 5 years, sooner in a warm room.
Static IP access
Necessary but not sufficient: a single link remains a single point of failure.
On-call logistics
Someone who knows the cooling has failed, and who drives over — at night, at the weekend, in August.
Diesel generator
Mandatory for genuine 24/7: automatic start, load testing, a fuel contract.
Compliance and insurance
Fire detection and suppression, the annual electrical inspection, an insurance surcharge: obligations, not options.
Without a generator, “24/7” actually means “24/7 as long as the grid holds”.
Server room, datacenter, RDEM Systems
The same criteria, item by item.
| Criterion | In-house server room | Standard datacenter | RDEM Systems |
|---|---|---|---|
| Air conditioning | your responsibility | redundant, monitored | redundant, monitored |
| UPS and generators | your responsibility | included | included |
| On-site technicians | business hours only | 24/7 | 24/7 |
| User access from the offices | not applicable: servers on the LAN | link to be sourced separately | private L2 link, can be doubled over 2 paths |
| Network | corporate LAN | shared | dedicated VLAN, private addressing, AS206014 |
| BCP / DRP distribution | impossible on a single site | contract-dependent | several Equinix Paris sites |
| On-call logistics (cooling, power) | you | the hosting provider | the hosting provider |
| Systems on-call (your servers) | you | not included | 70 € excl. VAT/month per server 7am-10pm, 150 € for 24/7, tapering from 5 servers |
| Single point of contact for network incidents | your operator | host or operator | RDEM Systems, server and link |
Orders of magnitude
Orders of magnitude observed on the market in 2026 — colocation in the Paris region, links anywhere in France. Neither firm prices nor an RDEM Systems price list: real figures depend on your address, the power capacity you contract and your volumes.
In-house room — recurring, hardware excluded
- Electricity0.25 € excl. VAT / kWh
- Air conditioning servicing250 to 300 € / year / cooling unit
- UPS load testing1,000 to 1,500 € / year
- UPS batteriesevery 3 to 5 years
- Diesel generatorservicing, load tests, fuel
- Dual electrical feedrarely possible in an office building
- Depreciation: cooling, UPS, generatorover 8 to 10 years, servicing aside
- Cooling, power, UPS, fire call-outs4 contract options to negotiate
Datacenter — recurring
- Hosted 1U server, 100 to 150 W100 to 200 € / month
- Quarter rack, 1 kVA contracted400 to 500 € / month
- Half rack, 2 kVA contracted700 to 800 € / month
- Full rack1,200 to 2,000 € / month
- Power contracted beyond the allowance150 to 250 € / kW / month
- Dark fibre, unlit500 to 900 € / month
- Managed FTTO linkfrom 100 € / month
- Cooling, UPS, generators, techniciansincluded
The arithmetic for five servers
Five 1U servers, 300 W each, running continuously. Every figure excludes VAT and is an order of magnitude for 2026, IT hardware aside.
1. The room as you find it — around 600 € excl. VAT a month
5 × 0.3 kW × 8,760 h × 0.25 € excl. VAT = 3,285 € excl. VAT a year to power the machines. A small room rarely gets below a PUE of 2: budget the same again for cooling and conversion losses, so roughly 6,600 € excl. VAT a year. Add 500 to 600 € excl. VAT a year of servicing for two cooling units — a single one would mean its failure stops the room. Total: close to 600 € excl. VAT a month. That figure is the one you have in mind, and it is accurate: it is what the electricity supplier and the refrigeration engineer invoice you. It is not the cost of the room, it is its visible part — the part of a room with no generator, no formal on-call cover and no value put on the floor space.
2. What that invoice does not say
| Item missing from the invoice | Basis | € excl. VAT / month |
|---|---|---|
| Floor space tied up, 10 to 12 m² | Paris-region office rent, 200 to 350 € / m² / year | 170 to 350 € |
| 24/7 call-out extensions on four contracts | cooling, electrical, UPS, fire suppression | an option, negotiated per contract |
| Annual UPS load test | one day of electrical contracting, 1,000 to 1,500 € excl. VAT | 85 to 125 € |
| 3 to 5 kVA UPS depreciated over 8 to 10 years, plus battery sets | 2,000 to 3,500 €, plus 400 to 700 € a set | 30 to 50 € |
| Generator and transfer switch, depreciated over 10 years | 8,000 to 15,000 € | 65 to 125 € |
| Generator servicing, load tests, fuel | 800 to 1,500 € / year | 65 to 125 € |
| Replacing the two cooling units, depreciated over 10 to 12 years | 8,000 to 15,000 € | 55 to 125 € |
| Fire detection and suppression, annual inspection included | 4,000 to 8,000 €, plus around 400 € / year | 60 to 100 € |
| Statutory annual electrical inspection | 300 to 800 € / year | 25 to 65 € |
| Total not counted | 555 to 1,065 €, call-outs aside |
The UPS load test is run every year. What it costs is not the production outage: it is the engineer's day, high-voltage electrical contracting billed by the day. And if it turns up a fault, the service outage comes on top.
On-call cover is not staffed: it is negotiated as an option on each maintenance contract, and you need four — the refrigeration engineer, the electrician, the UPS vendor, the fire suppression provider. Four line items, four distinct response commitments, four numbers to dial at 3 a.m. without knowing which is the right one. It is the item no budget carries, because it is only discovered when something breaks. Also uncounted: a dual electrical feed, which most office buildings simply cannot provide, and the insurance surcharge.
3. The same room at parity with a datacenter — at least 1,150 to 1,650 € excl. VAT a month
600 € of visible cost, plus 555 to 1,065 € of items that never appear as an identifiable invoice line: the floor space, the UPS load tests, compliance and replacement. And that total is a floor — the four call-out extensions come on top, as do the dual feed and the insurance surcharge. The 25,000 to 40,000 € of equipment — UPS units, cooling units, generator, fire detection and suppression — is replaced roughly every ten years, and no monthly invoice reminds you of it: that is what makes an in-house room painless right up until it is not.
4. In a datacenter — 650 to 900 € excl. VAT a month, link included
The 100 to 200 € excl. VAT per U range assumes an allowance of 100 to 150 W per U: at 300 W apiece, these five machines draw 1.5 kW — barely more than 1.5 kVA, since the power factor of a modern IT supply with active correction sits around 0.98 — and the unit of account is no longer the U. Two arrangements carry that load: a quarter rack at 1 kVA contracted, 400 to 500 € excl. VAT a month, plus the additional kW contracted on top at 150 to 250 € excl. VAT per kW per month; or a half rack at 2 kVA contracted, 700 to 800 € excl. VAT a month. Either way, in the order of 550 to 800 € excl. VAT a month, cooling, UPS units, generators, fire detection, a dual feed and round-the-clock technicians all included. On volume the threshold moves quickly: the quarter rack beats renting by the U from three or four U; beyond that it is contracted power, more than the number of U, that moves you to a half then a full rack. Add the link to your offices: from 100 € excl. VAT a month for a managed FTTO we order, light and support, or 500 to 900 € excl. VAT a month for dark fibre you light yourself at both ends.
An in-house room is not cheaper: it is less invoiced. At parity of service it costs at least one and a half to two times a quarter or half rack, link included — before the four call-out extensions, which widen the gap further. And that gap is about scale, not principle. Air conditioning servicing, UPS and generator testing, compliance, on-call cover: these items are close to fixed. Spread across forty racks they become marginal per server and a private room is perfectly rational — that, after all, is a datacenter's own business model. Spread across five servers, they are carried whole. At RDEM Systems, the rack infrastructure and the inter-datacenter fibres of our backbone are shared across several customers: each pays a fraction of a redundancy none of them would fund alone. What you buy by moving out is that economy of scale, and an on-call rota someone already staffs — for you and for their other customers. On-call cover for your own servers is not part of this calculation: it is the one item the move does not remove, and it is handled separately.
What you buy, and what we add
A datacenter sells an environment. We add the distribution.
In a reputable datacenter
Cooling, power and shared contracts, with largely redundant equipment. The items that crush a small room — cooling units, UPS, generators, fire detection, technicians on site at night — are shared across every customer on the site, and included in the price of the rack.
What RDEM Systems adds
The distribution. By spreading your requirement across several rooms, one room going down affects you only partially — and rooms do go down, despite every precaution datacenters take: the OVH SBG2 fire in Strasbourg in 2021, the temperature rise at Equinix PA4 on which we published a detailed account, or the Redbus Courbevoie power outage in March 2006, which we lived through as a SIVIT customer at the time.
A single host on a single site exposes you entirely to its worst day. Our production is spread across several Equinix datacenters in the Paris region, and backups are replicated to two geographically distinct sites.
How many contracts, and of what kind
| Model | Contracts to keep alive | Kind |
|---|---|---|
| Private room | 5 to 7 in parallel: air conditioning, UPS, generator, fire suppression, electrical inspection, internet access, the lease on the room | CAPEX + OPEX |
| Datacenters contracted directly | 1 per physical location, plus the inter-datacenter links to order, pay for and monitor as soon as you spread out | OPEX only |
| Datacenters operated by RDEM Systems | 1 only, whatever the number of physical locations — the inter-datacenter links are part of our shared backbone | OPEX only |
The trap is in the middle row. Spreading across two sites to guard against one room going down means connecting those sites to each other: as many links to qualify, order, pay for and monitor, each with its own operator and its own restoration commitment. It is the item comparisons forget, and it is exactly the one that sharing absorbs.
Two ways to bring us in
Depending on whether you want to remain the contract holder.
Consulting only
You contract directly with the datacenter and the fibre operator. We scope the requirement, write the technical specification and run the migration. You remain the contract holder.
Relevant when contractual control is an objective in itself.
Consulting, hosting and fibre
Your machines — virtual or physical — sit in our racks at Equinix Paris, connected to your offices by a private link we order and support. One contract, one point of contact for both the server and the link. The racks, the network infrastructure and the inter-datacenter fibres of our backbone are shared across several customers: you pay a fraction of them, not the whole. It is also what human-scale managed services make possible: someone who knows your infrastructure, not a ticket number.
Relevant when you would rather not arbitrate between host and operator.
In either model, day-to-day operations can be handed to RDEM Systems under 24/7 managed server services, or stay with your team. It is the one item the move does not remove: the datacenter takes on cooling, power, the generator and fire suppression, but it never touches your servers. If you would rather delegate systems on-call, it is a separate service, billed per server per month and tapering from five servers — and you are not replacing anyone: your team keeps the projects and the escalation, we take level 1 and the nights.
Frequently asked questions
19 answers, each readable on its own.
The underlying question
What a server room actually costs at small scale
Is running your own server room still worth it in 2026 for just a few servers?
For fewer than about ten servers, rarely. The dominant cost is not the IT hardware, it is the environment around it: air conditioning and its service contract, UPS units and their batteries, internet access with a static IP, and an on-call rota for the day the cooling fails on a Sunday in August. These items do not shrink when you go from 30 servers to 3: they are close to fixed. That non-linearity is what makes an in-house server room expensive at small scale — and, symmetrically, what makes it sound at forty racks, where the same costs spread across a volume that renders them marginal.
What is the biggest cost in an in-house server room?
Being on call, not the hardware. A UPS is bought once; knowing that it switched to battery at 3 a.m. on a Saturday requires monitoring and someone who will drive over. And not just anyone: a failed room calls on four trades — cooling, electrical, UPS, fire suppression — none of which an SME keeps on staff for on-call duty. In practice each one is negotiated as an option on the corresponding maintenance contract, and each option is billed. So an in-house room does not have an on-call rota: it has four separate call-out extensions to negotiate, four distinct response commitments and four numbers to dial at 3 a.m. without knowing which is the right one. A datacenter has a single one, and it is already answered. An in-house server room turns a one-off investment into a permanent obligation to be available — which is exactly what a datacenter shares across its customers.
When does an in-house server room still make sense?
In two cases. First, when a constraint exists that a datacenter cannot satisfy: very low latency to local physical equipment (industrial controllers, a production line), data volumes no link can carry at a reasonable cost, or a regulatory obligation to keep the systems on site. Second, when scale changes the nature of the calculation: air conditioning servicing, UPS and generator testing, compliance, on-call cover — these items are near-fixed. Carried by five servers they crush the budget; spread across forty racks they become marginal per server, and a private room becomes rational again. That is exactly the economy of scale a datacenter shares across its customers. Outside those two cases, an in-house server room is an inheritance rather than a decision.
Roughly what does an in-house server room cost?
There are two answers, and that is the whole problem. The room as you find it costs around 600 € excl. VAT a month for five 300 W servers: powering the machines at 0.25 € excl. VAT per kWh, roughly 3,300 € excl. VAT a year, about the same again for cooling and conversion losses since a small room rarely gets below a PUE of 2, plus 250 to 300 € excl. VAT per year per cooling unit of air conditioning servicing — and you need two, otherwise one failure stops the room. That figure is accurate, but it is the visible part: the part of a room with no generator, no formal on-call rota and no value put on the floor space. The same room at parity of service with a datacenter comes to at least 1,150 to 1,650 € excl. VAT a month. On top come the floor space tied up — ten to twelve square metres of Paris-region office space, 170 to 350 € excl. VAT a month — the annual UPS load tests, depreciation of the UPS units, the generator and the cooling units, fire detection and the statutory annual electrical inspection. The 25,000 to 40,000 € of equipment is replaced roughly every ten years, and no monthly invoice reminds you of it. And that figure is a floor: on-call cover is not staffed, it is negotiated as an option on each maintenance contract, and you need four — cooling, electrical, UPS, fire suppression. Left out of the calculation: a dual electrical feed, which most office buildings cannot provide, and the insurance surcharge. An in-house room is not cheaper: it is less invoiced.
Roughly what does datacenter hosting cost?
Orders of magnitude observed in the Paris market in 2026, not firm prices. Expect 100 to 200 € excl. VAT per month for a hosted 1U server — a range that assumes a power allowance of 100 to 150 W per U, with anything beyond that contracted and billed at 150 to 250 € excl. VAT per kW per month. Above the U come the quarter rack, usually 1 kVA of contracted power for 400 to 500 € excl. VAT per month, the half rack, 2 kVA for 700 to 800 € excl. VAT per month, and the full rack, 1,200 to 2,000 € excl. VAT per month depending on the contracted power capacity and the site. The quarter rack becomes cheaper than renting by the U from three or four U; beyond that it is contracted power, more than the number of U, that moves you to a half then a full rack. On top of that comes the link to your offices, and two distinct products answer that need. Dark fibre is unlit fibre, with equipment you supply at both ends: expect 500 to 900 € excl. VAT per month, anywhere in France, depending on the provider and the distance. An FTTO link is managed, lit and supported end to end: it starts at 100 € excl. VAT per month and is priced on bandwidth, address and the restoration guarantee taken out with the operator. RDEM Systems supplies both. The colocation and dark fibre ranges are orders of magnitude observed in 2026; the link itself is quoted once your address has been qualified.
What a server room actually requires
Six dependencies, six contracts, six points of failure
What does a server room actually require to run properly?
Six dependencies, all mandatory: dedicated air conditioning with its service contract; UPS units and periodic battery replacement; internet access with a static IP; on-call logistics, which is not staffed but negotiated as an option on each maintenance contract; for genuine 24/7, a diesel generator; and compliance — fire detection and suppression, the annual electrical inspection, an insurance surcharge. Each one is a point of failure, each one needs a contract, and none of them shrinks when the number of servers goes down.
Is a UPS enough to guarantee power continuity?
No. A UPS covers a short outage — from a few minutes to half an hour depending on sizing. Beyond that you need a source that generates: a diesel generator, with automatic start, periodic load testing and a fuel contract. Without a generator, “24/7” actually means “24/7 as long as the grid holds”.
How often must air conditioning and UPS batteries be serviced?
Room air conditioning is contracted with periodic visits, typically twice a year. Sealed lead-acid UPS batteries are replaced every 3 to 5 years — and age faster in a warm room. The two dependencies therefore compound: an undetected cooling failure also shortens the life of your batteries.
Is a static IP enough to expose a service to the outside?
It is necessary, not sufficient. A single internet link remains a single point of failure: if the link drops, the room is intact but unreachable — which, from the user's point of view, is indistinguishable from an outage.
Moving to a datacenter
What you have to put in place, and what you are actually buying
What do you actually need to move servers to a datacenter?
Three things: a fibre link between the offices and the datacenter so users can reach it, a hosting contract (signed directly or subcontracted), and where relevant a split across several sites. Everything else — cooling, power redundancy, on-site technicians — is included in the hosting contract.
What are you really buying when you move to a datacenter?
Cooling, power and shared contracts, with largely redundant equipment. A reputable datacenter sells an environment whose availability is its core business: redundant and monitored cooling, redundant power with UPS units and generators, technicians on site around the clock. In a datacenter, the floor space is in the price. In an in-house room, it is in your lease: ten to twelve square metres of Paris-region office space taken away from desks to hold noise and heat — you pay for them too, you just do not see it. What you buy in a datacenter is someone already being there, at night, when the cooling fails.
Should you spread your infrastructure across several datacenters?
It depends on what an outage costs you. A single site is enough for standard availability requirements. As soon as a business continuity (BCP) or disaster recovery (DRP) plan is required, splitting across several distinct datacenters becomes the answer, with a role assigned to each site: primary, continuity, recovery. At RDEM Systems, production is spread across several Equinix datacenters in the Paris region and offsite Proxmox backups are replicated to two geographically distinct sites.
What if the datacenter itself fails?
It happens, despite every precaution. We publicly document one we lived through ourselves: the temperature rise at Equinix PA4, on which we published a detailed account. The difference is not that a datacenter never fails — it is that it fails with teams on site, written procedures and redundancy, whereas an in-house server room fails with a switchboard. And it is exactly why we spread your requirement across several rooms: one room going down then affects you only partially.
If my servers are 30 km away, who physically handles them?
The datacenter's own technicians, on site around the clock and working from written procedures: it is an included service known as remote hands. That is the paradox of moving out: your machines are further from you, but closer to someone. In an in-house server room, the person able to intervene is also 30 km away once it is 3 a.m. on a Sunday — except that they are asleep, and nobody is paying them to be reachable. On our own racks at Equinix Paris these interventions are covered by our contract: no badge to request, no trip to plan.
How RDEM Systems fits in
The link, the two engagement models, the entry point
How does RDEM Systems connect offices to the datacenter?
Through a private layer-2 link between your offices and our equipment at Equinix Paris: dedicated VLAN, private addressing, no transit over the public internet. We qualify your address for eligibility, order the link from the local loop operator — a managed FTTO we light and support, or dark fibre if you prefer that model — and remain accountable for it: we are the ones holding the backhaul contract with the operator, so you have no telecom contract to sign. Traffic then lands on our own network, AS206014, whose routing we control and whose addresses we announce ourselves. Where continuity demands it, the connection is doubled: two fibres following two physically distinct paths. The distinction matters: two links on the same path only protect against equipment failure; two paths also protect against a backhoe.
Can you hire RDEM Systems for consulting only?
Yes, two models exist. Consulting only: you contract directly with the datacenter and the fibre operator, and we scope the requirement, write the technical specification and run the migration. Consulting, hosting and fibre: your machines sit in our racks at Equinix Paris and we carry the whole chain, from the server to the link. The first model suits you if you want to remain the contract holder.
How many contracts do you have to manage under each hosting model?
A private room means 5 to 7 contracts to maintain and keep alive in parallel — air conditioning, UPS, generator, fire suppression, the statutory electrical inspection, internet access, the lease on the room — and a mix of CAPEX and OPEX, since the equipment is bought and then replaced. Contracting directly with datacenters moves you to OPEX only, but with one contract per physical location: as soon as you spread across two sites so as not to depend on a single room, you also have to order, pay for and monitor the inter-datacenter links, each with its own operator and its own restoration commitment. With RDEM Systems it is a single contract whatever the number of physical locations, OPEX only, the inter-datacenter links being part of our shared backbone.
Who covers on-call for the servers once they are in a datacenter?
It is the one item that moving to a datacenter does not remove: the host takes on cooling, power, the generator and fire suppression, never your servers. In house it comes as weekly on-call premiums, employer contributions included, for one person who will not cover fifty-two weeks a year. Handed to RDEM Systems, systems on-call is billed at 70 € excl. VAT per server per month from 7am to 10pm, or 150 € excl. VAT for 24/7, tapering from five servers — and the package is not just about answering the phone: operational maintenance, monitoring, Proxmox Backup Server backups included, an intervention credit. You are not replacing anyone: your team keeps the projects and the escalation, we take level 1 and the nights. What disappears is not a job — it is the on-call line on the payroll and the obligation to be reachable at 3 a.m. for a full disk.
Do you need to rent a full rack to get started?
No. The entry point is a virtual machine on our Proxmox platform: from 22 € excl. VAT/month for 1 vCPU, 4 GB of RAM and 50 GB of SSD, with daily backup replicated to two sites included, up to 132 € excl. VAT/month for 8 vCPUs and 32 GB of RAM — see Proxmox VPS hosting pricing. Your own servers can also sit in our racks at Equinix Paris, with volume and pricing set by quote — a quarter rack, which the market usually negotiates in 2026 at around 1 kVA of contracted power for 400 to 500 € excl. VAT per month, is enough to house a few servers. Our racks, our network infrastructure and the inter-datacenter fibres of our backbone are shared across several customers: you are not funding, on your own, a redundancy sized for everyone. For larger infrastructures, managing a dedicated cluster on your own hardware is billed at 150 € excl. VAT/month per hypervisor.
Let us run the numbers on your server room
Machine count, service contracts in force, latency constraints: the initial audit is free, and it concludes just as readily with “keep your server room” as with the opposite.
Contact
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