Solar system for a 3 marla house in Lahore

Start with the roof, not the bill

Almost every solar quote starts from the electricity bill. For a 3 marla house that is the wrong end. The roof decides the system size long before the bill does, and pretending otherwise is how customers in Sanda, Gulshan Ravi and Harbanspura end up paying advance for panels that physically cannot be mounted.

A 3 marla plot is 75 square yards, roughly 675 square feet of ground. The roof is never 675 square feet of clean deck. Subtract the stair block, which on most Lahore 3 marla houses sits in one corner and eats 60 to 80 square feet including its shadow. Subtract the water tank, another 25 square feet plus a long afternoon shadow. Subtract a 1.5 foot margin along the parapet so the crew can actually walk and clean. Subtract whatever the family has already built up there, and on half the houses that is a small store room or a chaddar shed over the washing area.

What is left is usually 300 to 360 square feet. Call it 340 as a working average.

The panel math

A 585W panel measures about 2.28 by 1.13 metres, so 28 square feet of glass. Mounted in a tilted row with a walkway and enough gap that the front row does not shade the back row in December, the real footprint per panel is closer to 40 to 45 square feet. Divide 340 by 42 and you get eight panels on paper. In practice, because the usable area on a 3 marla roof is broken into two or three awkward strips rather than one rectangle, the crew fits four to six.

Usable roof area	Panels that actually fit	DC capacity	Typical monthly units
Under 250 sq ft	3 to 4	1.75 to 2.3 kW	230 to 300
300 to 360 sq ft	5 to 6	2.9 to 3.5 kW	380 to 470
400 sq ft plus (rare)	7 to 8	4.1 to 4.7 kW	530 to 620

So the honest answer to "what solar system for a 3 marla house" is 2 kW to 3 kW for most homes, and 4 kW only if the roof is bare and the stair block is on the north side. Anyone quoting 6 kW for a 3 marla house is either planning to build a steel canopy over the whole roof or has not visited the property. Read the full 3 kW solar system price breakdown if the numbers below need more detail.

What a 3 marla household actually runs

Typical load in these homes, measured off jobs done around Baghbanpura and Mughalpura near our own office on Mohni Road:

• Six to eight ceiling fans, roughly 75W each on a stabiliser
• Twelve to sixteen LED bulbs and tube lights
• One fridge, sometimes a second small one on the roof room
• One 1 or 1.5 ton AC in the main bedroom, run four to six hours a night in June and July
• Washing machine twice a week, water motor twice a day, one TV, phone chargers

That is 380 to 550 units a month in summer and 180 to 260 in winter. A 3 kW system generates around 400 to 440 units in April and May, dropping to 250 in December and further in the smog weeks when Lahore does not see clear sun for days. The winter dip is real and is covered in more detail in the winter solar output guide for Lahore.

Two builds that make sense at this size

Build A: 3 kW hybrid, no battery

Five 585W panels, a 3 kW hybrid inverter, standard mounting, full electrical kit. The inverter is hybrid rather than on-grid so a battery can be added in year two or three without replacing the main box. Daytime load runs off the panels, evening load comes off LESCO. Installed cost sits around PKR 310,000 to PKR 340,000.

Build B: 3 kW hybrid with a 2.5 kWh lithium battery

Same panels and inverter, plus one 2.5 kWh lithium module wired to a backup distribution board carrying fans, lights, the fridge and the TV. That is three to five hours of load shedding cover, not a whole night with the AC on. Installed cost is roughly PKR 450,000 to PKR 480,000.

Item	Detail	Cost (PKR)
Panels	5 × 585W tier-1 @ 19,500	97,500
Hybrid inverter	3 kW single phase	95,000
Lithium battery	2.5 kWh	138,000
Mounting structure	Standard, 3 kW @ 7,000/kW	21,000
Electrical items kit	Breakers, SPD, DC box, earthing	35,000
Wiring	DC 90m + AC 20m	25,000
Installation labour	2 day crew	20,000
Net metering paperwork	Optional at this size	15,000
Total with battery	Turnkey	446,500
Total without battery	Turnkey	308,500

Battery choice matters more than panel brand at this size, because the battery is a third of the bill. Current rates are listed on the lithium battery price page, and if the budget is genuinely tight the lithium versus tubular comparison is worth ten minutes.

The shading problem nobody mentions

3 marla plots in Lahore sit on streets 20 to 25 feet wide, and the neighbours have been building upward for a decade. A house on a 25 foot street with a four storey building to its west loses direct sun from about 3:30 pm in winter. That is not a small loss. It can cut annual generation by 15 to 20 percent, and no inverter setting fixes it.

Two things help. Panels can be moved to the strip that clears the neighbouring parapet, even if that means an odd layout. Or the array goes on an elevated structure at PKR 12,000 per kW instead of PKR 7,000, lifting the panels above the stair block and the neighbour's wall. On a 3 kW system that is PKR 15,000 extra, which is usually worth it if it recovers a fifth of the output. The installation service page explains how the elevated frames are built.

Should a 3 marla house bother with net metering

Honest answer: often no. LESCO net metering paperwork costs around PKR 15,000 through us, plus the meter and the wait, and a 3 kW system in a house consuming 450 units a month exports very little surplus. Under the 2026 rules the export rate is far below the retail tariff, which sits between PKR 48 and PKR 65 per unit depending on the slab, so the recovery on that PKR 15,000 is slow.

Where it does make sense: a house that is empty during the day because everyone works, so most of the generation would otherwise be wasted. In that case apply, and read what changed in net metering in 2026 first. Otherwise skip it and go the solar without net metering route, which is what most of our 3 marla customers now choose. Either way the net metering service page lists the documents needed.

The honest downside of solar on 3 marla

Payback is slower than on a bigger house. A 10 marla owner spends more but saves proportionally more, because their consumption is high enough that every unit generated displaces an expensive slab unit. A 3 marla home on a protected tariff may be paying PKR 48 per unit, and a PKR 310,000 system saving 350 units a month recovers about PKR 17,000 monthly. That is a payback near 18 months on paper, but only if the whole generation is consumed, which it rarely is.

The second issue is roof access. Families use these roofs. Charpais come up in summer, laundry dries there year round, and once panels take 340 square feet the roof is gone as living space. Several customers have asked to shift the array to an elevated frame after installation specifically to get the floor back, and that rework costs more than doing it right the first time.

Third, dust. Small roofs near Ravi Road, Shad Bagh and the Mughalpura railway side collect a heavy grey film. Output drops 12 to 18 percent within six weeks in the dry months. Panels need washing every three to four weeks in summer, which the family can do with a soft brush, or through our cleaning service. Rates are on the solar cleaning cost page.

When to skip 3 kW and just buy a battery

Some 3 marla owners come to us wanting solar when what they really want is load shedding cover. If the bill is under PKR 8,000 a month and the complaint is power cuts, a hybrid inverter with a battery and no panels at all is the cheaper answer, and panels can be added later. That is a legitimate build, covered on the hybrid and battery page and in the IPS versus solar battery comparison.

Neighbours in Johar Town and Model Town with larger plots take a different path entirely, and the sizing logic there is not the same as here.

What happens on survey day

The survey fee is PKR 3,000 and it is deducted from the final installation bill. On a 3 marla house the visit takes about 45 minutes. The engineer measures the clear deck, checks the stair block and tank shadows against the sun path, opens the main DB to see the existing wiring and earthing, checks the sanctioned load on the LESCO bill, and photographs the neighbouring buildings on the south and west. The written layout that follows shows exactly where each panel sits.

To get a rough figure before booking, put the monthly units into the solar calculator, or send the last bill through the contact page. If the panels themselves are the question, the 585 watt panel page covers current rates and what to check on delivery.