Recommendations in the energy certificate — worth following?

An energy performance certificate must contain recommendations for cost-effective measures to improve the building's energy performance, where such measures exist. The recommendations are advisory — there is no duty to carry them out, and the certificate does not become invalid because they sit unactioned. The question is instead what they are actually worth as decision support, and the answer depends entirely on what the energy expert had access to.

What the recommendations rest on

They are produced by the energy expert from the building's data and the inspection carried out. That means two things that are easy to forget:

• They are calculated on the building as it was at the inspection. If you have since replaced the air handling unit, rebalanced the system or renovated a roof, the recommendation describes a building that no longer exists.
• They take no account of your organisation. A recommendation can be technically correct and still wrong for you, because it collides with a planned pipe replacement, a tenancy agreement or a procurement cycle.

Neither objection makes the recommendations worthless. They make them a starting point, not a decision.

The questions to put to every recommendation

Question	Why it decides
Which building element is affected, and when is it due for replacement anyway?	A measure co-ordinated with a planned replacement costs a fraction of the same measure as its own project
What is the saving based on — measured data or a standard figure?	Both occur, and they bear different weight in an investment decision
Does the measure affect the indoor environment?	Tightened buildings without adjusted ventilation give worse air. See ventilation remarks
Is the building's energy data corrected to a normal year?	Without correction you are comparing weather, not measures
Does the recommendation appear on several buildings in the portfolio?	The same measure on twelve buildings is one procurement, not twelve projects

The last row usually yields the most, and it is invisible in the individual certificate. A recommendation read per building is a small project; the same recommendation read across the whole portfolio is a programme.

Are the recommendations worth following?

As a direction yes, as an investment decision no — not without recalculating against the building's actual operating data and against what is going to be done anyway. The recommendations are produced by an independent expert and normally point to the right kind of measure for the building type, but they know neither your maintenance plan nor your procurement calendar. The most common and most expensive mistake is implementing an envelope-tightening recommendation without reviewing the ventilation at the same time, because the result is a building that uses less energy and has worse air.

Never calculate without normal-year correction

To judge what a measure delivered you must compare energy year with energy year, and no two years are equally cold. Without correction for outdoor temperature you are measuring the weather. The degree-day method corrects district heating consumption against a normal year, and only then does the difference say anything about the measure.

It is also why follow-up is so often absent: it requires a data chain that has to exist before the measure. Without consumption data from the preceding years the effect cannot be demonstrated afterwards, however good the measure was.

What we do not claim

We state no payback periods and no saving percentages for individual measures. They vary with building, location, energy price and execution, and a general figure would be wrong in most individual cases. If you see a finished number in a demo or a worked example — including in our own product — it is an example, not a measurement of your building.

What we do is place the certificate's data per building, alongside the rest of the status, so the recommendations can be read across the whole portfolio instead of one PDF at a time. See energy certificates in Emphyx and energy class A–G for how the class is calculated from the numbers.

If you have a single house, the cheapest next step is to take the certificate's recommendations to an energy consultant who inspects the building on site. A portfolio needs a sort instead: same measure, all buildings, one decision.