By Viktor Malovs, Principal Consultant
Having spent many years analysing energy-intensive buildings including leisure centres, sports complexes, and office buildings that have exactly the same characteristics in terms of heat loads and energy use as hotels, we found a number of problems recurring almost in all analysed buildings. These problems have nothing to do with anything exceptional or extraordinary. They are quite common.
Here are the seven we encounter most often, roughly ordered by how much they typically cost.
1. Running a single large boiler for baseload and peak
Most hotels have one or two large gas boilers, sized for the coldest day at full occupancy. For 90% of the year, those boilers cycle on and off at a fraction of their rated output, wasting energy on every cycle. Standing losses, flue losses at part-load, and the inefficiency of constant modulation add up to 15–25% more gas consumption than a properly staged system.
What to do instead: A lead-lag configuration with a smaller condensing boiler handling baseload (or a heat pump, where feasible) and the larger boiler covering peak demand only. In the properties we’ve assessed, this single change typically saves £8,000–£25,000 per year depending on property size.
2. Heating corridors, conference rooms, and back-of-house areas to guest room temperature
Guest rooms need to be comfortable. Corridors, stairwells, storage areas, and unoccupied conference rooms do not need to be 21°C. In many hotels, the heating system makes no distinction — the entire building is treated as a single thermal zone with one setpoint.
What to do instead: Zone your heating system. Corridors and circulation spaces can be maintained at 16–18°C without any guest impact (people are passing through, not sitting still). Back-of-house and storage areas can be lower. Conference rooms should only reach guest comfort temperature when booked. This reduces heating demand by 10–15% with minimal capital cost — often it requires only controls adjustments and TRV installation.
3. Ventilating at the same rate regardless of occupancy
Building regulations specify minimum ventilation rates for occupied spaces. Many hotel ventilation systems run at these rates (or higher) regardless of whether the space is occupied or empty. A restaurant with 3 tables occupied at 3pm receives the same fresh air volume as it does with 60 covers at 7pm.
What to do instead: Demand-controlled ventilation using CO2 sensors in occupied spaces. When CO2 levels are low (indicating low occupancy), ventilation rates reduce automatically. When the restaurant fills up, rates increase. The technology is mature, the sensors are inexpensive, and the savings on fan energy and the heating or cooling of incoming air are significant — typically 15–25% reduction in ventilation-related energy costs.
4. Generating all hot water by gas boiler with no pre-heating
Hotels use large quantities of hot water — showers, baths, basins, kitchen, laundry. In most properties, the incoming cold mains water (at roughly 10°C in winter) is heated entirely by the gas boiler to 60°C. That’s a 50-degree temperature lift, all delivered by burning gas.
What to do instead: Pre-heat the incoming cold water before it reaches the boiler. Two straightforward technologies: drain water heat recovery (a passive heat exchanger on the shower/bath wastewater pipes, capturing 10–15°C from the outgoing greywater) and ventilation heat recovery (extracting heat from the warm, humid air being vented from bathrooms and kitchens). If the incoming water arrives at the boiler at 20°C instead of 10°C, the boiler does 20% less work. Neither system has moving parts, and both have 15-20 year lifespans.
5. Lighting that hasn’t been reviewed since the last refurbishment
This one is obvious, and yet we still find properties running metal halide fittings in car parks, T8 fluorescent tubes in corridors, and halogen downlights in guest rooms. The economics of LED conversion have been compelling for years — paybacks under 2 years are common, and the reduction in heat output from LED fittings also reduces the cooling load in summer.
What to do instead: Audit every fitting. Focus first on areas with the longest operating hours (corridors, reception, car parks, external lighting — these run 12–24 hours per day). Guest rooms are lower priority because operating hours per room are shorter. Add occupancy sensing in back-of-house, corridors, and toilets. The combined lighting and controls upgrade typically reduces lighting energy by 50–70%.
6. No sub-metering — so no visibility on where energy goes
If your energy bill shows total gas and total electricity, you have no way of knowing which systems are consuming what. Is your kitchen using more electricity than it should? Is the swimming pool’s heating cost reasonable? Is the HVAC running efficiently or struggling? Without sub-metering, every efficiency conversation starts with guesswork.
What to do instead: Install sub-meters on the major energy consumers: heating plant, hot water, HVAC (ideally per air handling unit), kitchen, laundry, swimming pool (if applicable), and lighting. The hardware cost is modest — typically £3,000–£8,000 depending on the number of meters. What it gives you is visibility: month-by-month consumption by system, the ability to detect anomalies early (a chiller running 24/7 when it should be seasonal), and a baseline against which to measure any improvements you make.
7. Treating maintenance and efficiency as the same thing
Many hotel operators assume that if the FM team keeps the boilers serviced, the HVAC filters changed, and the systems running, energy efficiency is being handled. It isn’t. Maintenance keeps equipment operational. Efficiency requires asking whether the equipment is the right equipment, whether it’s sized correctly, whether it’s controlled properly, and whether it’s working in conjunction with other systems or against them.
A well-maintained 20-year-old boiler that’s oversized for its current load and running without weather compensation is still wasting energy, even though it passes every maintenance check. The FM team’s job is to keep it running. Nobody’s job is to question whether it should be running the way it is. That’s the gap an energy assessment fills.
What to do instead: Commission an independent energy review at least once. Not from your maintenance provider (they have an inherent interest in the status quo), and not from an equipment supplier (they have an inherent interest in selling you their product). An independent assessment asks the questions that operational teams are not resourced or incentivised to ask.
The common thread
All seven of these mistakes persist because they’re invisible in the normal course of running a hotel. The bills get paid, the guests are comfortable, the boilers are serviced, and nobody has a reason to look deeper. The waste is real but silent.
An independent energy assessment makes it visible. We typically find that hotels with 50+ rooms can identify £15,000–£50,000 in annual savings from a combination of these measures, often with a blended payback of under 4 years.
If you’re curious about where your property sits, our free benchmarking tool compares your hotel’s energy performance against industry averages in under two minutes.
Or book a conversation with us to discuss your property directly.
ENEREKA is an independent energy consultancy. We have delivered decarbonisation strategies and energy retrofits across over 200 sites in the UK. A senior engineer is involved in every project.
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