The EPC is one document. What did the rest of the file say?

A 1950s detached house near Hasselt, roughly 150 m² (1,600 sq ft). The EPC says: label F, a score above 1,100 — nearly three times the legal target. An oil boiler at 48% efficiency. No insulation in the roof, the walls, or the floors. No ventilation system. The automated recommendations list runs to six figures if you follow it all the way to label A.

Read in isolation, the certificate tells a clear story: bad score, old house, big renovation. Start with the heating, then the roof, then the walls.

But the EPC is one document in a purchase file that contained six others. When we read them together, three things changed — and one turned out to be unexpectedly good news.

Finding 1: the heating system had no fuel

The EPC, inspected in late 2023, records an oil boiler running at 48% efficiency as the sole heating system. That much is visible on the certificate. What is not visible: the purchase file also contained an oil tank decommissioning certificate from April 2022 — more than a year before the EPC inspection. The underground tank had been emptied, cleaned, and permanently filled with foam.

Unless a new fuel supply was arranged after that date, the boiler the EPC describes has nothing to burn. The home very likely has no functioning heating.

That single cross-reference changed the heating decision from “important, plan it in” to “first, and before the first winter.” It also removed any temptation to nurse the old boiler along while planning the envelope works — there is likely nothing to nurse. This is not information the EPC can contain; it comes from reading one document against another.

Finding 2: the roof job was not an insulation job

The EPC’s roof recommendation is straightforward: 110 m² of pitched roof, uninsulated, insulate from the interior (around €6,000) or the exterior (around €30,000). Both estimates assume the existing roof covering stays in place.

The asbestos certificate — issued two years after the EPC — concluded niet-asbestveilig with 13 confirmed asbestos-containing materials. Three of them sat directly in the path of the EPC’s recommended measures. The most consequential: the corrugated roof sheets were asbestos cement, in poor condition, flagged for removal as soon as possible by a certified removal firm.

This reframed the roof measure entirely. Nothing may be mounted on or installed against an asbestos-cement roof — no solar panels, no over-roofing, no spray foam underneath. The realistic job was not “insulate beneath an intact roof” but “certified removal, new covering, and insulation in one operation.” Neither EPC cost estimate priced this, because the EPC did not know the roof was asbestos. Only contractor quotes could price it.

Two other asbestos findings mattered for the renovation plan. The pipe insulation in the cellar was non-bonded asbestos requiring hermetic-zone removal — the most involved removal class — and it wrapped the heating distribution, meaning its removal belonged inside the heating replacement job. And several “manage safely” materials — panels in window bays, wall paneling, sills — were stable if undisturbed but would become removal jobs the moment window, wall, or chimney work touched them. Every contractor quoting those jobs needed the attest in hand before quoting.

Finding 3: a second clock the EPC never mentions

The electrical inspection, carried out in early 2026, found a pre-1981 installation that did not conform to current standards. No earth electrode could be found. The bathroom lacked the required 30 mA protection. The residual-current device was the wrong type. No wiring diagrams existed. The violation list was long enough that, in a renovation of this scope, a full rewire was the realistic assumption — though an electrician’s assessment settles that definitively.

The legal consequence: re-inspection within 18 months of the deed. That clock runs out years before the EPC’s six-year renovation deadline. The practical move: fold the rewire into the first interior works, while walls and floors are already open, and size it for the heat pump, induction cooktop, and EV charger the home would eventually need.

The EPC contains no mention of the electrical installation. It cannot; it measures energy, not electrical safety. But the deadline is real, and scheduling it wrong — after the insulation and finishes are in — means cutting into freshly closed walls.

And one piece of good news the listing never mentioned

Not every finding is bad news. The EPC’s window section, buried in the technical fiches on page 13, recorded that all 23 m² of glazing was high-efficiency glass installed after 2000, in PVC frames, with a calculated U-value of 1.61. The EPC marked the windows green — reasonably energy-efficient — and recommended no replacement.

This matters because a buyer scanning the headline score of 1,100 could easily assume everything needs replacing. The windows did not. At roughly €10,000–€15,000 for a full set of new windows in a house this size, that is real money left in the budget for the work that actually moves the needle. Document review cuts both ways: it tells you what to spend on, and what not to.

The lesson

Every document in a Flemish purchase file answers one question: what does this change about the plan?

The soil certificates answered: nothing — and that was good news for a property that had run on heating oil from an underground tank for decades. The planning information confirmed the build year as 1950 (the EPC had listed it as unknown), noted no heritage listing and no flood risk, and filed away the presumption-of-permit status for future reference.

Most documents in most files will answer “nothing changes.” The ones that don’t — a decommissioned tank, a failing roof that is also asbestos, an electrical installation on a shorter legal clock — are worth the entire exercise. They are the difference between a renovation plan built on one document and a renovation plan built on the full picture.

Send us your file

If you have just bought a home in Flanders and your purchase file is sitting in a drawer because it is in Dutch: that is the problem we built this service for. Our Owner’s Decision Report reads your EPC and the key documents in your sale file against each other — the asbestos certificate, the electrical inspection, the planning information, the soil certificates, whatever the file contains — and delivers one plain-English report that tells you what changed, what didn’t, and what belongs in your contractor quotes from day one.

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This case study is based on a real property reviewed by EPCinEnglish.be. Details have been anonymized: no address, no certificate numbers, and areas are rounded. Rules as described are current as of June 2026.