Energy Saving in Rental Buildings: Lower Bills, Happier Tenants

Electricity, water and gas are among the biggest running costs of a rental building in Bangladesh, and most of that cost is invisible until the bill arrives. Common-area lights that stay on all day, a lift that runs half empty, a water pump that cycles every few minutes because of a leaking tank valve, a generator burning diesel during load-shedding: each one quietly eats into the landlord's income or inflates the service charge tenants pay. Energy saving in rental buildings is therefore not a green slogan. It is one of the most practical ways to protect your margins and keep tenants happy at the same time.

This guide is written for Bangladeshi landlords, building managers and flat-owner associations. It explains where energy is usually wasted in a typical Dhaka or Chattogram building, which fixes pay back quickly, how to split the savings fairly between landlord and tenants, and how to talk to tenants about it without sounding like you are policing their fans. Examples are illustrative; your own tariffs and usage will differ, so always work from your actual DESCO, DPDC, Palli Bidyut, WASA and Titas bills.

Why Energy Costs Matter More in Rental Buildings

In an owner-occupied home, the person who wastes electricity also pays for it. In a rental building, costs are split in ways that blunt that signal.

• Common areas are "nobody's" cost. Stair lights, the lift, the water pump, gate lights, the guard room fan and the CCTV system are usually paid by the landlord or shared through a service charge. No individual tenant feels the waste.
• Shared meters hide individual use. Where several flats or shops share a meter and split the bill, heavy users are subsidised by careful ones, which creates resentment.
• Tariff slabs punish bulk use. Residential electricity tariffs in Bangladesh are generally stepped, so the more a single meter consumes, the higher the rate on the extra units. A shared common meter can easily land in higher slabs.
• Service charges get questioned. When tenants see the service charge rising every year, the first question is "what are we paying for?". A building with visibly lower common-area costs is easier to justify.

If you are still working out how to divide utility costs between flats, read our guide on utility bills in a rented flat in Bangladesh first. Energy saving works best when everyone can see what they use.

Step 1: Find Out Where Your Energy Goes

You cannot save what you do not measure. Before buying anything, spend one month collecting information.

1. List every meter in the building: each flat or shop meter, the common meter, any separate pump or lift meter, and gas and water connections.
2. Collect 12 months of bills for the common meter at least. Look for seasonal peaks (summer cooling, winter water heating) and sudden jumps.
3. Walk the building at different times. At noon, are stair lights on? At 2 a.m., is the pump running? Is the lift lobby fan spinning in an empty corridor?
4. Count the loads. Write down every common-area appliance with its wattage and rough hours of use per day.
5. Ask the caretaker and guard. They know which motor overheats, which tank overflows and which light never goes off.

A simple common-area load sheet

Figures above are illustrative. The formula is what matters: watts × hours per day × 30 ÷ 1000 = monthly units. Once you have a sheet like this, the big items become obvious.

Lighting: The Fastest Win

Lighting is usually the easiest and cheapest place to start, because the equipment is cheap, installation is simple and the savings begin on day one.

• Replace old tube lights and CFLs with LED. An LED batten of similar brightness typically uses a fraction of the power of an old 40-watt fluorescent tube with a magnetic ballast.
• Add motion sensors or timers on staircases and corridors so lights only come on when someone is there, or only during evening hours.
• Use photocell (dusk-to-dawn) switches for gate and boundary lights so they are never left on in daylight.
• Use daylight. Clean stairwell windows and paint stairwells in light colours. It sounds trivial, but a bright stairwell needs fewer lights in the day.

For example (illustrative): LED payback on the stairwell

Take the 20 stair tubes from the table above, each drawing about 40 watts for 14 hours a day, using 336 units a month. Replacing them with 18-watt LED battens gives 20 × 18 × 14 × 30 ÷ 1000 = 151 units a month. Saving = 336 − 151 = 185 units a month.

If we assume, purely for illustration, an average cost of Tk 10 per unit on the common meter, the saving is 185 × 10 = Tk 1,850 a month, or about Tk 22,200 a year. If 20 LED battens cost roughly Tk 450 each installed, the outlay is 20 × 450 = Tk 9,000, which pays back in about 9,000 ÷ 1,850 ≈ 5 months. Add motion sensors so lights are on only 6 hours a day instead of 14, and usage falls further to 20 × 18 × 6 × 30 ÷ 1000 = 65 units. Check actual tariffs and prices before you plan, but the direction of the result is usually the same.

Water Pumps and Tanks

In most Bangladeshi buildings, water is pumped from an underground reservoir to a rooftop tank. The pump is one of the largest common loads, and water waste directly becomes electricity waste.

• Fix overflow first. A rooftop tank that overflows for twenty minutes every fill wastes both water and pump electricity. A float switch or automatic water-level controller stops the pump when the tank is full.
• Check for leaks. Dripping taps, running cisterns and hidden pipe leaks make the pump run more often. A simple test: note the tank level at night when nobody is using water, then check again in the morning.
• Right-size the pump. An oversized or ageing motor draws more power. When replacing, ask a qualified electrician or plumber to size it for your building height and demand.
• Clean tanks regularly. Sediment reduces flow and may cause dry-running damage to pumps.
• Schedule pumping in fixed slots rather than on demand all day, where water supply from WASA allows.

Lifts, Generators and IPS

Lifts

Lifts consume power both when moving and on standby. Regular servicing keeps motors and brakes efficient. Ask your lift maintenance company whether the lift's cabin lights and fan can switch off automatically when idle. Encourage tenants on the first and second floors to use the stairs where they are able, but never lock the lift or make it inconvenient for elderly or disabled residents.

Generators

A diesel generator during load-shedding is expensive per unit. You can reduce the cost by limiting which circuits run on generator: typically the lift, the pump, stair lights and one or two points per flat, rather than every air conditioner in the building. Keep the generator serviced; a poorly tuned engine burns more fuel. Keep a log of running hours and fuel purchases so you can split the cost fairly.

IPS and inverters

Many flats use IPS units. Old batteries that no longer hold charge draw power constantly while giving little backup. Encourage tenants to maintain their own units, and for common-area IPS, replace dead batteries rather than letting the charger work endlessly. Our article on load-shedding, generators and IPS for tenants covers cost-sharing in detail.

Sub-Meters: Letting Each Tenant Pay for What They Use

The single strongest energy-saving measure in many rental buildings is not a device but a billing change: giving each unit its own meter or sub-meter. When tenants pay for their own consumption, they naturally switch off fans, set AC temperatures sensibly and report faults quickly.

• Where possible, get separate meters from the distribution company (DESCO, DPDC, BPDB or Palli Bidyut) for each unit. Many utilities now install prepaid meters.
• Where that is not practical, install sub-meters and bill tenants on actual readings at the same effective rate the building pays.
• Read sub-meters on a fixed date each month, photograph the readings and share them with tenants.

Our step-by-step electricity sub-meter billing guide shows how to calculate each unit's share without overcharging.

Cooling: Fans, ACs and Building Heat

In Bangladesh's climate, cooling drives most summer peaks. Landlords can influence cooling demand even when tenants control their own appliances.

• Roof heat. Top-floor flats bake under an exposed concrete roof. Reflective roof paint, roof gardens or simple shading can reduce heat gain and make top floors easier to rent.
• Windows and shading. Sunshades (chhajja), curtains and light-coloured external walls reduce heat entering west-facing rooms.
• AC placement and maintenance. If you provide ACs in furnished flats, choose efficient inverter models where budget allows, service them before summer and clean filters regularly.
• Ceiling fans. When replacing fans in furnished units, energy-efficient fans (including BLDC types) use noticeably less power than older models.
• Cross-ventilation. Keep common windows and ventilation shafts open and clear so hot air can escape.

Gas and Cooking

Many older buildings have a Titas (or other distribution company) piped gas connection with a fixed monthly charge per burner, while others rely on LPG cylinders. With fixed-rate burners there is little financial incentive for tenants to save gas, and some people leave burners on to dry clothes or warm rooms. You cannot control every kitchen, but you can:

• Put clear safety rules in your house rules and agreement: no burners left on unattended, no use of burners for heating rooms.
• Check pipes, regulators and connections for leaks, which are a safety risk as well as a waste.
• For LPG, encourage proper cylinder storage and regulator checks.

Solar: Is It Worth It for a Rental Building?

Rooftop solar can reduce daytime common-area costs, especially for pumps, lifts and stair lights. Bangladesh has had a net-metering framework allowing some grid-connected rooftop systems to export surplus power, but eligibility and procedures depend on your utility and the current guidelines, so check directly before investing. Consider solar when:

• Your roof is structurally sound, reasonably unshaded and not already committed to a tower or billboard.
• Your common-area daytime load is significant.
• You plan to own the building for many years.

Our guide to rooftop solar for landlords in Bangladesh goes into costs, space and approvals.

Sharing the Savings Fairly

Energy upgrades raise a fair question: who pays, and who benefits? A simple framework keeps it fair:

Talking to Tenants About Energy Saving

Tenants respond far better to information than to rules. A short, friendly notice works better than a list of prohibitions.

Sample notice: Dear residents, we have replaced all stair and corridor lights with LED lights and added motion sensors, and fixed the tank overflow. These changes should reduce the common electricity bill. Please switch off lights and fans in the common rooms when not in use, and report any leaking tap or running cistern to the caretaker. Thank you for helping keep service charges stable. – Building Management

• Share the before-and-after common bill in the monthly notice. Visible results build trust.
• Give a quick way to report problems, such as a WhatsApp number or maintenance request form.
• Thank tenants who report leaks or faults quickly.

Common Mistakes Landlords Make

• Buying the cheapest LED lights. Very cheap fittings often fail within months, wiping out the savings.
• Ignoring the pump. Landlords change lights but leave a tank overflowing every day.
• Overcharging on sub-meters. Adding a markup to tenants' electricity is unfair, damages trust, and may create legal issues. Bill at the actual effective rate.
• Running every circuit on generator. Backup for every AC is extremely expensive and usually unnecessary.
• Not tracking results. Without comparing bills before and after, you never know what worked.
• Cutting safety to save money. Never switch off fire-exit lighting, emergency lights or fire pumps to save electricity.

A 90-Day Energy Saving Plan

1. Days 1–30: Collect bills, walk the building, build the load sheet, fix obvious leaks and overflows.
2. Days 31–60: Replace common lighting with LED, add sensors and photocells, service pump, lift and generator.
3. Days 61–90: Review sub-metering, compare the new common bill with the same month last year, share the results with tenants and decide on bigger investments such as solar or roof insulation.

Final Thoughts

Energy saving in rental buildings is mostly about attention: measuring what you use, fixing the obvious waste, and making sure each tenant pays for their own consumption. Start with lights and the water pump, then look at sub-meters, generator circuits and cooling. Track your bills month by month and share good results with tenants; they will notice.

If you already bill tenants through sub-meters, Bariwala ERP (বাড়িওয়ালা ERP) can record meter readings, calculate each unit's electricity bill and add it to the monthly invoice, while its expense reports let you compare common-area costs over time. Whether you use software or a notebook, the principle is the same: what gets measured gets managed.