The 2027 filing covers this year. Here is everything in it.

Who is in scope, and why the grace period matters

The EU Energy Efficiency Directive requires every data centre with an installed IT power demand of at least 500 kW to report annually: enterprise, colocation, or co-hosting, the type does not matter. Member states can widen the net and two big ones have. Germany reports at 300 kW of net connected power, measured at the grid connection rather than the racks, and files six weeks earlier than everyone else. France pulls the threshold down to 100 kW, which reaches server rooms that have never employed anyone whose job includes energy reporting.

The dates: German facilities file to the BAFA register by 31 March 2027, and the EU reporting platform closes on 15 May 2027. Both filings cover calendar year 2026. And a detail that matters for anyone who filed before: the first-cycle grace provisions, which let operators omit the hard-to-measure datapoints, no longer apply. The second cycle expects the full set.

The 24 datapoints, sorted by where the numbers live

The regulation asks for 24 datapoints across energy, water, waste heat, renewables, ICT capacity, and data traffic. Listed in the annex they look intimidating. Sorted by where the numbers actually come from, they fall into three piles.

Pile one: already in your accounts inbox

Total energy consumption, total water input, potable water input, and your renewable energy split across guarantees of origin, power purchase agreements, and on-site generation. These come off electricity bills, water bills, and certificates you already receive. The only real work is arithmetic done carefully: a bill that spans the year boundary contributes to the filing in proportion to the days that fall inside the reporting year, and every figure should stay traceable to the document it came from.

Pile two: facts you declare once

Total floor area and computer-room floor area, installed IT power demand, battery capacity, refrigerant types, the setpoint temperature of IT intake air, which grid functions the facility provides, the average temperature of any waste heat you reuse, and cooling degree days, which come from public climate data for your location. An afternoon with your facility documentation covers this pile, and most of it barely changes between years.

Pile three: the ones that need a meter or a method

The energy consumption of IT equipment is the denominator of your PUE, and without an IT submeter it is an estimate. ICT capacity for servers and storage, and the four bandwidth and traffic figures, need numbers from your network and asset systems. Colocation operators carry the extra wrinkle of reporting on equipment they do not own: the regulation allows extrapolation covering at least 90 percent of new-equipment IT power, which in practice means a data relationship with tenants that most contracts never anticipated.

From those 24 inputs the reporting platform computes four indicators: PUE, WUE, ERF, and REF. You do not submit the indicators; you submit the inputs that determine them. The quality of the filing is decided there.

Measured or estimated is a legal distinction

Nowhere is that clearer than Germany. The EnEfG attaches hard caps to measured PUE: existing facilities must reach 1.5 by July 2027 and 1.3 by 2030, and facilities entering operation from July 2026 must reach 1.2 within two years, with fines of €50,000 to €100,000 per infraction. An estimate cannot demonstrate compliance with a numerical cap. If a single estimated figure sits inside your total or IT energy numbers, the PUE computed from them is an estimate too, and nothing done after the fact converts it back.

This is the distinction that separates a defensible filing from paperwork. A first filing built from bills plus declared facts, with the gaps flagged honestly and a measurement plan for the next cycle, is defensible. A complete-looking filing built on unsourced estimates is not, and under a measured cap it is worthless.

The calendar runs backwards from the meter

The same logic applies to pile one. Bills collected as they arrive, into one folder, with the maximum-demand line noted while you are at it, turn February 2027 into an administrative event. Bills reconstructed in February from three supplier portals and a change of tenancy turn it into a project. If you have read our capacity piece, you already know the second reason to pull those bills: the maximum-demand figure on them is the key to how much headroom your grid connection is hiding.

What to do this quarter

1. 01Confirm which threshold catches you. The two-minute readiness check tells you whether the duty applies, under which regime, and which of the 24 datapoints you currently cannot produce.
2. 02Decide the measured-versus-estimated question now, not in February. If a measured PUE matters to you, and in Germany from July 2027 it is the law, a submeter installed this quarter is the difference between another estimated year and a measured one.
3. 03If you want the 2027 season done with you rather than to you, fifteen founding partner slots cover scope confirmation, the gap report, and the filing itself at £1,950 for the year. You review and sign everything: you remain the filer of record.

The filing is not hard. It is 24 numbers, most of which are already printed on documents you receive every month. What makes it hard is starting in February 2027 and discovering that the year you were supposed to measure ended five weeks earlier.