12 Deadly House Construction Mistakes in Nepal: Earthquake-Resistant Guide

Building a house in Nepal is a big dream for many, but house construction mistakes are extremely common here – and they often put people’s life savings at serious risk.

Scene: A small tea shop in Pokhara Time: 10:15 AM (a short break before the next concrete pour)

Characters:

• • Contractor Kaka: Cigarette in hand, hot glass of tea in front, 26 years of experience written all over his confident face.

• • Engineer Babu: Holding tea and dry bread, laptop and drawings in his bag.

1. Starting with “Copying the Neighbor”

Kaka took a long drag from his cigarette and said, “Hey Babu, you were saying the steel in that foundation wasn’t enough. Don’t you think you’re overdoing it? Look at the neighbor’s house – they used only 9-inch pillars with four 12mm bars and they’ve already built three floors. Nothing has happened to them, right?”

Babu chewed his bread and replied, “Kaka, copying your neighbor’s design is one of the biggest and most expensive mistakes in house construction in Nepal. Around 70% of people do exactly this. Their house might have survived the 2015 earthquake, but who can guarantee it will survive the next one? The latest NBC 105:2025 has introduced many changes in pillar size and reinforcement requirements.”

Kaka laughed, “Babu, these ‘codes’ of yours just empty people’s pockets! In the old days, we built houses with 9×9 inch pillars. Now you people say even 12×12 is too small!”

2. The Soil Mystery: “Our Land is Perfect!”

Kaka sipped his tea and added, “And why waste 25,000 rupees on a soil test? We’ve been digging here for years – the soil is as strong as rock.”

Babu smiled, “Kaka, even if it looks solid from the outside, there could be a risk of liquefaction underneath. In many parts of Kathmandu, the ground turns into liquid mud during earthquakes and buildings sink. Pouring foundations without a proper soil test is like shooting in the dark.”

3. Cheap Contractor vs “Bookish” Engineer

Kaka: “Now we’re talking money. The owner is looking for a cheaper contractor. Someone quoted 2 lakh rupees less than me!”

Babu: “Kaka, a cheap contractor always cuts corners somewhere – either less steel, weaker concrete mix, or poor workmanship. In five years, the house starts leaking, and that ‘saved’ 2 lakh turns into 5 lakhs in repairs. When choosing a contractor, look at their previous projects and experience, not just the price.”

4. Map Approval: “Tricking the Municipality”

Kaka chuckled, “Map approval is just for show, Babu! One thing on paper, something else on site. When the municipality guy comes, we just offer him tea and he leaves.”

Babu: “That’s exactly the problem, Kaka. In 2083 (2026/27), the rules have become very strict. If you build without proper approval or violate the bylaws, you won’t get a Completion Certificate. Banks won’t give loans, and later you risk having the house demolished by a government bulldozer.”

5. The Steel Game: Fe 415 or Fe 500?

Kaka stubbed out his cigarette, “Steel is steel, Babu. Whatever you put, it should be fine!”

Babu: “No, Kaka! Fe 415 is now outdated. Today we need Fe 500 or Fe 550 TMT bars. They make the structure more flexible during earthquakes. And another thing – why are you bending the stirrup hooks at only 90 degrees? They must be bent at 135 degrees!”

Need to calculate rebar weight quickly?

Click here to use our free Rebar Length & Weight Calculator -specially made for house construction in Nepal.

6. Quick List of 12 Common House Construction Mistakes (from the Tea Shop Debate)

While drinking tea, Babu shared this list with Kaka:

1. 1. Starting without a proper design — “You can’t build a house just by taking photos of your neighbor’s home.”

1. 1. Skipping the soil test — “Only an engineer knows what’s really under the ground.”

1. 1. Falling for cheap rates — “A cheap contractor makes the project expensive later.”

1. 1. Violating the approved map — “Municipal fines will make you cry later.”

1. 1. Using fake or substandard materials — “Always check the brand of cement and steel, not just the price.”

1. 1. Wrong hook and lapping — “Bending stirrup hooks at only 90° instead of 135° is inviting disaster.”

1. 1. Poor waterproofing — “Once the roof leaks, the steel inside starts corroding.”

1. 1. Cutting pillars for pipes — “Stop breaking beams and columns to run plumbing pipes.”

1. 1. Soft story — “Keeping the ground floor completely open for parking while building heavy floors above is very risky.”

1. 1. Budget shortage — “Better to build a smaller but strong house than leave it half-finished.”

1. 1. No proper curing — “After pouring concrete, you have to ‘feed’ it water like a baby for at least 2 weeks.”

1. 1. Not planning for the future — “Building a foundation for only 2 floors and later adding 5 is suicidal.”

7. Curing: “The Lazy Mason Who Skips Watering”

Kaka said, “Babu, pouring water for just 2 days after casting is enough. Why 14 days? The mason is in a hurry to go to the next site.”

Babu: “That’s exactly why cracks appear! Concrete needs water to gain strength. Without proper curing for 14 days, it can lose 30–40% of its final strength.”

8. Plumbing & Electrical: Breaking Pillars or Using Sleeves?

Kaka: “We always chisel the walls and pillars after casting to run electrical and plumbing pipes. Why complicate it now?”

Babu: “This is one of the top 90% mistakes in Nepal! Cutting into columns and beams after casting reduces their strength by up to 40%. NBC 105 clearly says you should never make holes in the middle of beams. We must install sleeves or pipes before pouring concrete so we don’t need to hammer later.”

9. Soft Story: “Open Ground Floor, Heavy Floors Above”

Kaka: “Everyone wants parking space these days, Babu. What’s wrong with keeping the ground floor completely open?”

Babu: “That’s actually very dangerous! Engineers call it a Soft Story. During the 2015 earthquake, many new buildings in Kathmandu collapsed like a ‘jackknife’ because of this. If you keep the ground floor open, you must add shear walls or stronger columns — otherwise the house behaves like a house of cards.”

10. Careless Budgeting: “Half House, Half Loan”

Kaka: “The owner says he has 70 lakh. Let’s build three floors — it should be enough, right?”

Babu: “It won’t be, Kaka! Many people make this mistake. They start construction, run out of money midway, and then compromise on steel and cement. According to current 2083 market rates, a good 3-storey house usually costs more than 80 lakh. That’s why we created the Cost Estimator on Nirman Sutra. Always prepare a proper Bill of Quantities (BOQ) before starting.”

11. Waterproofing: “When the Roof Leaks, the Steel Starts Rusting”

Babu explained how tiny capillaries in concrete allow water to reach the steel, causing oxidation (rust). Rust makes the steel expand, which cracks the concrete from inside (called spalling). Once rusting starts, the steel can lose up to 50% of its strength.

Babu’s 5 Waterproofing Tips (Kaka listened carefully):

1. 1. Slope is King — Give the roof at least a 1:100 slope so water flows naturally to the pipes.

1. 1. Don’t rely only on cement slurry — Use proper chemical membranes or bitumen sheets instead.

1. 1. Coving in bathrooms — Make rounded corners where floor meets wall to prevent leaks.

1. 1. Use Non-shrink Grout where pipes meet the slab.

1. 1. Do it during construction — It’s cheaper and far more effective than fixing leaks later.

12. Future Expansion: “Foundation for 2 Floors, Planning for 5”

Kaka: “The owner wants to get approval for 2 floors now and add more later when he has money.”

Babu: “That’s even more dangerous! If the foundation and pillars are designed only for 2 floors, adding 3–4 extra floors later can cause the whole building to sink. If you plan to expand in the future, you must calculate the extra load from the beginning and make the foundation and columns stronger. It’s wiser to invest a little more now than regret later.”

Conclusion: The Final Sip of Tea

As the tea finished, Kaka stood up and said, “Babu, some of what you say makes sense. But it’s hard to explain all this to the owner — he just wants to save money.”

Babu replied while picking up his bag, “Kaka, you might save money today, but during an earthquake, that saved money won’t save lives. That’s why we built tools.nirmansutra.com. Tell the owner to check it — it has everything: material quantities, cost estimates, and guidance on how to build strong.”

Kaka smiled, “Alright, let’s go back to the site. Today I’ll make sure the mason bends those hooks at 135 degrees!”

What’s happening at your construction site? Is your contractor saying “Kehi hudaina” (Nothing will happen) like Kaka, or are you following Engineer Babu’s advice for a safer home?

Comment below:

1. 1. What size are the pillars in your house?

1. 1. Did you get a soil test done?

If you’re confused or in the middle of planning, take advantage of NirmanSutra’s BOQ service (only Rs. 999) and build with confidence under proper engineering guidance.

If you haven’t read the first part of this series, start here: “ Is it safe to build a 3-storey house on 9-inch pillars? ”

Is a 9-inch pillar safe for a 3-storey house?

According to the current NBC 105 standards, the minimum recommended column size for residential buildings is 12” x 12” (300mm x 300mm). 9-inch pillars are generally considered unsafe for earthquake resistance.

Why is a soil test mandatory before building?

Soil that looks strong on the surface can be weak underneath. Without knowing the bearing capacity, there’s a high risk of settlement or cracks later.

Why must stirrup hooks be bent at 135 degrees?

During an earthquake, columns try to burst outward. A 90-degree hook can open easily, but a 135-degree hook holds the steel tightly and prevents collapse.

What to check before adding extra floors to an old house?

Get a Structural Audit done by an engineer first. Adding floors without checking the existing foundation and columns can be extremely dangerous.

When is the best time for waterproofing?

During or right after concrete pouring – not after the house starts leaking.

Did you read Series-1 if not read this