Electrical, plumbing and air-conditioning basics

General guidance, not professional design. Wiring, plumbing and air-conditioning should be designed and installed by qualified people who can see your building. Utility rules change, so check with your local Nepal Electricity Authority (NEA) office and water provider.

Wiring, pipes and air-conditioning disappear inside walls and ceilings, so mistakes are expensive to fix later and can be dangerous. You do not need to be an expert, but knowing what to ask helps you hire well and check the work before it is plastered over.

Plan early, on paper

Decide where things go before the walls are built, while changes are still cheap.

• List the appliances you expect now and in the next few years: induction cooker, water heater (geyser), air-conditioners or heat pumps, washing machine, water pump, inverter, electric vehicle charger, rooftop solar.
• Mark sockets, switches, lights, fans, AC units, taps, drains and the water tank on a copy of your floor plan.
• Ask your designer for electrical and plumbing drawings. The National Building Code includes NBC 207 (electrical design requirements for public buildings) and NBC 208 (sanitary and plumbing design requirements); your engineer will know which apply to your building.

Electrical: what to ask your electrician

1. What load do we need? Add up the main appliances. This decides the size of the connection and meter you apply for from NEA, and whether a three-phase supply makes sense. Ask your NEA office which connection options are available.
2. How many circuits? Lights, ordinary sockets and each heavy appliance (geyser, AC, induction cooker, pump) should be on separate circuits, each with its own breaker (MCB) in the distribution board.
3. What wire sizes and which brand? Wire size must suit the load and the length of each run. Use copper wire from a reputable brand, with the size and brand printed on the insulation, run inside conduit pipes. Avoid joints buried in walls: joints belong in accessible junction boxes.
4. Is there earth-leakage protection? Ask for an RCCB or RCBO in the board. It cuts power quickly if current leaks to earth, for example through a person, and is especially useful for bathrooms, kitchens and outdoor sockets.
5. How will the house be earthed? Every socket should be three-pin with a working earth wire, and metal bodies (geysers, pumps, washing machines, steel water tanks) should be earthed. Ask how the earth pit will be made, and ask the electrician to measure earth resistance with a tester and show you the reading.
6. Do we need lightning protection? For tall buildings, exposed hilltop sites or rooftop solar arrays, ask your engineer.

Other good practice:

• Keep sockets and switches well away from showers, sinks and taps; use splash-proof fittings in bathrooms and outdoors.
• Label every breaker in the board so anyone can switch off the right circuit.
• Ask for a final as-built wiring sketch showing where cables run, so nobody drills into them later.

Getting connected to NEA

NEA's new customer application page lists the documents to submit with the application: citizenship certificate, land ownership certificate (Lalpurja), the building approval certificate, a ward recommendation and a photograph. NEA states that the wiring and materials in the house must meet its standards and that supply starts only after its inspection; the contractor who did the wiring must be present at the inspection, and the first inspection is free while a re-inspection may be charged. Extending the wiring later needs NEA's prior notice and approval. Never tamper with the meter or service line.

Plumbing: what to ask your plumber

1. Which pipes, and why? Different pipes suit different jobs: plastic pipes made for hot water inside the house, cold-water plastic pipes, polyethylene for buried supply lines, and separate drainage pipes. Ask the plumber to name the type and brand for each, and whether it is rated for hot water and your water pressure. Older galvanised iron (GI) pipes rust over time.
2. Will you pressure-test before we plaster or tile? Supply pipes should be filled, pressurised and left for a period to show there are no leaks. Be there when it is done.
3. Are drains sloped and trapped? Every sink, shower and toilet needs a trap (water seal) to keep sewer smells out, drains need a steady fall, and the system needs vent pipes and inspection chambers so blockages can be cleared.
4. Where does waste go? If there is a municipal sewer, ask about the connection permission. If not, the septic tank and soak pit should be designed by your engineer and kept away from wells and water tanks.
5. How is the bathroom waterproofed? Floors and the lower walls of showers should be waterproofed and tested (for example by flooding the floor for a day) before tiles go on. Do the same for flat roofs and terraces.
6. What about water storage? Ask about tank sizes, the pump, a non-return valve, an overflow, and easy access for cleaning the tank.

For water heaters, make sure a pressure relief valve is fitted and that the drain from it goes somewhere safe. Solar water heaters need a strong, well-anchored base on the roof.

Air-conditioning, heating and ventilation

• Size the unit for the room. A good installer asks about room size, sun exposure, number of people and insulation, rather than guessing. Inverter models usually use less electricity for the same comfort.
• Use an authorised installer. Many brands require installation by their authorised service network for the warranty to be valid. Ask before you buy.
• Plan the outdoor unit: a strong bracket or base, enough air around it, a safe way to reach it for servicing, and a proper drain for condensate water so it does not drip on neighbours or walls.
• Give each AC its own circuit and earth connection.
• Ventilate kitchens and bathrooms with exhaust fans or a chimney hood. Damp, unventilated rooms grow mould.
• Never burn charcoal or use gas heaters in a closed room. They produce carbon monoxide, which has no smell and can kill. Keep a window open and choose electric heating for bedrooms.

Simple maintenance

• Press the test button on the RCCB regularly; if it does not trip, call an electrician.
• Check the earth pit and its connections every year, especially before the monsoon, and re-test earth resistance if anything changes.
• Clean AC filters often during heavy use and get the unit serviced by a qualified technician.
• Clean water tanks regularly and check for leaks under sinks and around toilets.
• Watch for warning signs: warm switches or sockets, burning smells, breakers that trip often, damp patches on walls or ceilings, and slow drains. Fix them early.

Quick checklist

• Appliance list and marked-up floor plan before walls go up
• Separate circuits, MCBs and an RCCB/RCBO in a labelled board
• Branded copper wire in conduit; three-pin earthed sockets; earth resistance measured
• NEA documents ready; wiring contractor present at NEA inspection
• Pipe types named for each use; pressure test witnessed before plaster or tiles
• Traps, vents, slopes and inspection chambers on drains; bathrooms and roofs waterproofed and tested
• AC sized properly, installed by an authorised installer, on its own circuit
• No charcoal or gas heaters in closed rooms