Efficiency First: Energy Security Starts in Your Building

Every few years, Europe has the same argument with itself. A shock hits, a war, a pandemic, a conflict in the Gulf, and the price of gas and oil lurches. Governments scramble for supply, cap bills, and hunt for new import routes. Then prices settle, the urgency fades, and the underlying problem goes untouched until the next shock.

That underlying problem, argued in a recent policy brief by Professor Jan Rosenow of the University of Oxford, has two faces. One is the obvious dependence on imported fossil fuels. The other is quieter and rarely named: the structural energy waste that decades of relatively cheap fossil fuel allowed us to keep prolonging. No shock, not even the war in Ukraine, has closed that gap.

Here is the number that should reframe how you think about your own energy bill. Across the EU, energy efficiency has already avoided 249 Mtoe of demand since 2000, roughly 29% of 2024 consumption. That is energy Europe never had to generate, import or pay for. At any given price, the continent pays about 29% less than it otherwise would. And that logic does not stop at the border of a national grid. It runs all the way down to your building.

The Quick Version

Efficiency, electrification and clean power are one system, not three competing priorities. Rosenow’s image is a three-legged stool: weaken one leg and the whole thing falls over.
Efficiency is the “first fuel”, the cheapest energy is the energy you never use. It is also the leg that makes the other two affordable.
The same forces play out in a single building. The cheapest way to cut your exposure to volatile energy prices is to stop wasting energy first.
Ireland has the same problem, sharper: around 81% fossil dependence and 80% imported energy, with commercial electricity prices among the highest in the EU.
The first move is never a big capital purchase. It is an energy audit and monitoring to see where the waste is.
SEAI supports the audit and many upgrades, where eligible.

One System, Not Three Tracks

Efficiency, electrification and renewables are usually treated as three separate campaigns, each competing for attention and funding. Rosenow’s argument is that this framing is the mistake. They are one integrated system, and each leg amplifies the others.

Efficiency reduces the energy that has to be supplied at all. A smaller demand means a smaller grid, a smaller import bill, and less pressure at every price level.

Electrification shifts what remains onto electricity, the one energy carrier that can be produced at home from clean sources. Every heat pump, electric vehicle or electrified process is a unit of imported oil or gas you no longer have to buy.

Renewables clean the grid that electrification depends on. Without more clean power, electrifying just moves demand onto gas-fired generation and delivers far less benefit.

The compounding effect matters more than any single leg. As the brief puts it, the effect of combining strategies consistently exceeds the sum of the individual interventions. The canonical example is a heat pump in a well-insulated building running on renewable electricity. That one investment cuts fossil exposure three ways at once: it lowers total demand, removes the gas boiler, and delivers its full benefit on a clean grid. Do the same thing in a leaky, badly controlled building and most of the benefit leaks straight back out.

Europe’s own record shows the pattern. The power sector has moved fast: the fossil share of EU electricity generation fell from 53% in 2005 to below 30% by 2024. But electricity is only about a quarter of final energy use, and the harder sectors are still overwhelmingly fossil-fuelled, transport around 92%, buildings 71%, industry 61%. Power shows what is possible when the policy conditions are right. The rest of the economy has further to travel, and buildings are where a lot of that journey happens.

This is the same three-legged logic behind smart HVAC controls: the controls are the efficiency leg, and they are what let a building electrify sensibly later.

Efficiency Is the First Fuel

If the three legs are one system, why lead with efficiency? Because it is the only leg that is pure gain. Every other option adds capacity or swaps one fuel for another. Efficiency removes the need in the first place. The cheapest, cleanest, most secure unit of energy is the one you never use.

It is also the leg with the fastest payback and the lowest upfront cost, which is exactly why it belongs first. In the EU modelling, efficiency does roughly a third of the heavy lifting on gas demand reduction on its own, and it shrinks the job that electrification and renewables then have to finish. In a building, the sequence looks like this.

See it first

You cannot cut what you cannot see. Most buildings run on a decade of accumulated assumptions: a heating schedule set by a contractor years ago, equipment nobody switches off, a bill nobody reads line by line. The starting point is visibility.

A commercial energy audit gives you a one-off diagnostic: where the energy goes, benchmarked against similar buildings, with a prioritised list of what to fix and in what order. Continuous monitoring gives you the ongoing picture, your overnight baseload, your weekend consumption, and how each system actually behaves hour by hour. That “29% you don’t pay for” always starts with knowing where the waste is. Guessing keeps it in place.

Control it

Once you can see the waste, most of the early savings come from control, not replacement. The single most common finding in a building audit is heat and light being delivered to empty space: an office warmed to 21°C over a weekend nobody works, corridors lit through daylight hours, a plant running long after everyone has gone home.

This is where a building energy management system earns its keep. Optim EOS, our BEMS, connects sensors, controllers and gateways into one platform and turns that data into automatic control: heating and cooling scheduled to real occupancy, setpoints held sensibly, zones treated separately so you stop heating rooms nobody is in. None of this replaces the heating plant. It just stops the plant running when it should not. It is the cheapest efficiency you can buy, and it is the layer that everything else builds on.

Fix the fabric

Where the numbers justify it, the fabric of the building comes next: insulation, draught-proofing and glazing that reduce how much heat you need to put in at all. Fabric work is more capital-intensive and slower to pay back than controls, which is why it comes after the quick wins, not before them. But it compounds with everything else: a better-insulated building needs a smaller heat source, so it makes the final step cheaper.

Then electrify

Electrification is where most buildings are heading, and it is the right destination. But it lands far better on a building that is already efficient and already monitored. Right-size a heat pump for a leaky building and you oversize it, overspend, and shift a large bill from gas to electricity. Right-size it for a building whose demand you have already cut and whose controls already work, and the switch is smaller, cheaper and quicker to pay back.

To be clear about where we sit: our starting point is always the efficiency and monitoring layer, the audit, the BEMS, the controls that cut waste and make the later steps pay. Electrification, solar and storage are the direction of travel that this layer sets up, and the efficiency work is what makes them worth the investment. The point is the sequence. Efficiency first is not a delay on electrification. It is what makes electrification worth doing.

The Same Logic, Sharper in Ireland

The EU picture is the backdrop. The Irish picture is more urgent. According to SEAI’s Energy in Ireland 2025, around 81% of the country’s primary energy still comes from fossil fuels and roughly 80% of all energy is imported. That makes Ireland one of the most energy-dependent countries in Europe, so global price shocks land here harder and faster than almost anywhere else.

That dependence shows up directly on business bills. Irish commercial electricity prices are consistently among the highest in the EU, typically 20% to 30% above the EU average, a product of an island grid, limited interconnection, and heavy reliance on imported gas for generation. On top of that sits a carbon tax legislated to rise to €100 per tonne of CO2 by 2030, which pushes up the cost of gas and oil year after year regardless of what wholesale markets do.

Put those together and the “first fuel” argument stops being abstract. In a market this exposed and this expensive, every unit of energy you stop wasting is worth more than it would be almost anywhere else in Europe. Efficiency is not the environmental option here. It is the cost-control option, and it happens to be the security option too. It is also increasingly the compliance option: the EPBD is bringing minimum energy performance standards to Irish commercial buildings, and the worst performers face requirements first.

What This Costs, and What Doing Nothing Costs

The technologies are mature and the case is well evidenced. Across a full efficiency programme, from audit through monitoring and controls to the deeper measures, modelled savings run up to around 30%, with the fastest measures paying back inside one to three years. The exact figure depends on your building, how it is used today, and, crucially, whether anyone keeps watching the data after the work is done. Savings drift away within a couple of years if the controls get overridden and nobody notices.

The upfront cost is lower than most owners expect, because the first steps are cheap and grant-supported. SEAI supports the audit through the Energy Audit Voucher and funds upgrades such as heating controls and building energy management systems through the Business Energy Upgrades Scheme, where eligible, and qualifying equipment can attract the Accelerated Capital Allowance. Amounts and eligibility change, so we link the official SEAI sources rather than quote figures that date, and we handle the application as part of the work.

Rosenow frames the alternative neatly. The cost of trading away efficiency for short-term convenience is the mirror image of the 29% Europe has already banked. It is the cost of inefficiency, and it grows the longer the waste goes unaddressed. At the level of a single Irish business, that is exactly the choice on the table: keep paying to heat empty rooms on imported gas at some of Europe’s highest prices, or find the waste and cut it. The first move is the same as it is for the whole continent. See it first, then fix it.

Frequently Asked Questions

What does “efficiency first” mean for a small business?

It means the cheapest unit of energy is the one you never use, so the first move is not new kit but cutting waste. In practice that is an energy audit and monitoring to see where your building loses energy, then controls to stop heating and lighting empty space. These steps are low-cost or grant-funded, they pay back fastest, and they make every later upgrade work harder. You cut the bill before you spend a cent on generation.

Do I need to electrify to cut my energy bill?

No. Electrification is where most buildings are heading, but it lands far better in a building that is already efficient and monitored. If you electrify a leaky, badly controlled building you just move a big bill from gas to electricity. Fix the waste first, and the eventual switch to electric heat is smaller, cheaper and pays back sooner.

Where does energy security come into a single building?

Every unit of gas or oil you stop burning is a unit you no longer buy from an imported, price-volatile market. Ireland imports around 80% of its energy, so a building that wastes less is directly less exposed to the next price shock, whatever its cause. Efficiency is the one lever that protects you at every price level, because it works regardless of what happens to wholesale markets.

Are efficiency upgrades grant-eligible in Ireland?

Many are, where eligible. SEAI supports energy audits through the Energy Audit Voucher and funds upgrades such as heating controls, building energy management systems and lighting through the Business Energy Upgrades Scheme, and qualifying equipment can attract the Accelerated Capital Allowance. Amounts and eligibility change, so we point you to the official SEAI sources and handle the application as part of the work.

How do I know where my building actually wastes energy?

You measure it. A commercial energy audit gives you a one-off diagnostic and a prioritised action plan, and continuous monitoring through a BEMS shows you the ongoing picture: baseload overnight, weekend consumption, and how each system behaves hour by hour. Without that visibility you are guessing, and guessing is what keeps the waste in place.

Europe keeps relearning the same lesson: the fastest way to reduce exposure to volatile fossil fuel prices is to stop wasting energy in the first place. The same is true of your building. Electrification and clean power are where it is all heading, but efficiency is the leg you pull first, because it is the cheapest, it pays back fastest, and it makes everything after it work harder.