Electrical Wiring Estimate for a 100 Gaj House

 For a 100 gaj house (approximately 900 sq. ft. or 83.6 m²),generally concealed copper wiring system using FRLS (Flame Retardant Low Smoke) insulated wires, separate circuits for air conditioners and heavy appliances, and an appropriately rated distribution board (DB) with modern electrical protection to be used.

The following is a preliminary quantity and cost estimate for a typical 2–3 BHK house with a kitchen, bathrooms, living room, bedrooms, and a small utility area.

Important: The wire sizes and quantities below are planning estimates. Final sizing depends on actual connected load, circuit length, installation method, voltage drop, ambient temperature, grouping, and the applicable electrical standards.

1. Assumptions for the Estimate

Particular	Assumption
Covered area	100 gaj (900 sq. ft.)
House configuration	2–3 BHK, single floor
Wiring method	Concealed conduit wiring
Conductor	99.9% copper, FRLS insulated
Supply	230 V single-phase, subject to sanctioned load
Air conditioners	3 split ACs
Lighting points	25
Ceiling fans	5
6A socket points	15
16A power points	8
Geysers	2
Kitchen heavy appliances	Microwave, refrigerator, washing machine and other appliances as applicable
Distribution board	Modular DB with MCBs, RCCB/RCBO protection and surge protection as appropriate

The estimate assumes that the house is already constructed or being fitted out and that the work includes wiring, conduits, accessories, and distribution-board installation. Major civil repairs, plastering, painting and premium decorative fixtures are excluded unless specified.

2. Recommended Wire Sizes for Different Appliances

Wire size should be selected according to the actual load, current-carrying capacity, voltage drop, installation conditions and protective-device rating. India's relevant reference standard is IS 732:2019 — Code of Practice for Electrical Wiring Installations. BIS

Sr. No.	Circuit / Appliance	Recommended copper wire size for preliminary planning	Suggested circuit protection*
1	LED lights	1.5 mm²	6A or 10A MCB
2	Ceiling fans	1.5 mm²	6A or 10A MCB
3	General 6A sockets	2.5 mm²	10A or 16A MCB
4	Refrigerator	2.5 mm²	Dedicated 16A circuit where appropriate
5	Television and computer	2.5 mm²	10A or 16A MCB
6	Washing machine	2.5 or 4 mm²	Dedicated circuit; rating based on appliance
7	Microwave oven	2.5 or 4 mm²	Dedicated circuit; rating based on appliance
8	1-ton split AC	2.5 or 4 mm²	Dedicated 16A/20A circuit, subject to load
9	1.5-ton split AC	4 mm² as a planning provision	Dedicated circuit; typically 16A/20A subject to manufacturer requirements
10	2-ton split AC	4 or 6 mm²	Dedicated circuit, sized by calculation
11	2 kW geyser	2.5 or 4 mm²	Dedicated circuit; typically 16A, subject to design
12	3 kW geyser	4 mm²	Dedicated circuit; protective rating based on design
13	Kitchen heavy appliances	2.5 or 4 mm²	Separate circuits according to appliance loads
14	DB to room sub-distribution board, if provided	6 or 10 mm²	Based on aggregate demand and route
15	Main incoming supply	10 or 16 mm² may be considered	Based on sanctioned load, demand and supply arrangement

*These are indicative selections, not final design ratings. The electrician must calculate the actual current, verify the wire's derated ampacity, coordinate MCBs with the cable and account for voltage drop and fault protection.

Buy House Wiring Kit by clicking at Image or Link

Special recommendations for AC wiring

For a typical house with three split ACs:

• Bedroom 1: Independent AC circuit.
• Bedroom 2: Independent AC circuit.
• Bedroom 3 / drawing room: Independent AC circuit.
• Provide a suitable isolator near each outdoor unit as required by the manufacturer's instructions and applicable standards.
• Do not connect multiple ACs to one general-purpose socket circuit.
• Keep an adequate earth conductor with each circuit.

Engineering recommendation: Do not select AC wire size solely on the basis of tonnage. Check the nameplate current, rated input, maximum operating current, cable length, installation conditions and manufacturer's instructions before finalising the wire size.

---

3. Detailed Electrical Wiring Quantity Estimate

The following quantities are budgetary estimates for a 900 sq. ft. house. Actual quantities can vary significantly depending on the room layout, location of the DB, number of switchboards and routing of concealed conduits.

A. Copper wire requirement

For estimating purposes, assume standard 90-metre wire coils. Quantities below represent the approximate combined length of conductors in all required colours, including phase, neutral and earth where applicable.

Sr. No.	Wire size	Estimated total length	Equivalent 90 m coils	Main application
1	1.5 mm² copper FRLS	900 m	10 coils	Lighting and fans
2	2.5 mm² copper FRLS	900 m	10 coils	General sockets and selected appliance circuits
3	4 mm² copper FRLS	360 m	4 coils	ACs, geysers and heavy appliances
4	6 mm² copper FRLS	180 m	2 coils	Selected higher-load circuits/submain
5	10 mm² copper FRLS	90 m	1 coil	Main/submain wiring, if required
6	4 mm² green/yellow earth conductor	90 m	1 coil	Supplementary earthing and circuit earths, as designed
	Total	2,520 m	28 coils	Preliminary provision

Important quantity note: The 2,520-metre total is the sum of the conductor lengths, not the length of the physical cable route. For example, a 20-metre route may require separate phase, neutral and earth conductors. Earth conductors should be included in the actual circuit take-off, and the additional 4 mm² earth provision above should not be treated as a substitute for them.

The final purchase should be based on a room-wise wiring layout and an actual site measurement. Do not order all coils solely on the basis of this preliminary table.

B. Conduit, boxes and accessories

Sr. No.	Material	Estimated quantity	Unit
1	Heavy-duty PVC concealed conduit, 20 mm	250	Metres
2	Heavy-duty PVC concealed conduit, 25 mm	75	Metres
3	PVC junction boxes	25	Nos.
4	Modular switch boxes of various sizes	20	Nos.
5	Modular switchboards and plates	20	Nos.
6	6A switches	40	Nos.
7	16A switches and socket outlets	8 sets	Sets
8	6A socket outlets	15	Nos.
9	Fan regulators	5	Nos.
10	Ceiling fan hook boxes	5	Nos.
11	Light/fan outlet boxes	25	Nos.
12	AC isolators/suitable local disconnectors	3	Nos.
13	Conduit bends, couplers, saddles and accessories	1	Lot
14	Insulation tape, connectors, screws and consumables	1	Lot

These quantities assume concealed conduit installation. If the house has already been plastered, chasing, plaster repair and repainting may add substantially to the cost.

---

4. Distribution Board (DB) and Protection System

For a house with three ACs, two geysers, kitchen appliances and normal lighting loads, a properly designed distribution board is essential.

Recommended DB specification

Sr. No.	Component	Preliminary specification	Quantity
1	Main distribution board	18-way or 24-way modular DB, subject to circuit schedule	1
2	Main incomer	DP main isolator, typically 40A/63A as determined by load	1
3	RCCB	30 mA residual-current protection, with suitable type and rating	As designed
4	RCBOs	Individual overcurrent and residual-current protection for selected circuits	As designed
5	MCBs	Suitable ratings and breaking capacity for each circuit	As required
6	Type 2 SPD	Surge protection device, if required by the installation's risk assessment and design	1 set
7	Neutral and earth bars	Correctly rated and arranged	1 set
8	Earthing system	Suitable electrodes/connections and protective earth conductors	As required

Important: An 18-way or 24-way DB is a starting point, not a confirmed requirement. Finalise its size after preparing the circuit schedule. The main MCB rating must not be selected merely because the house has three ACs.

A 30 mA RCCB/RCBO provides additional protection against electric shock; it does not replace earthing or overcurrent protection. Neutral conductors must be arranged correctly, and circuits protected by separate RCBOs must not have their neutrals improperly interconnected.

For Indian installations, refer to the applicable requirements of the Bureau of Indian Standards (IS 732:2019) and the Central Electricity Authority's safety regulations.

5. Electrical Load Estimate

The connected load of a typical 100 gaj house may be estimated as follows. These are illustrative loads, not measured appliance ratings.

Sr. No.	Appliance	Quantity	Assumed load per unit	Total connected load
1	LED lights	25	12 W	0.30 kW
2	Ceiling fans	5	70 W	0.35 kW
3	Television	2	100 W	0.20 kW
4	Refrigerator	1	250 W	0.25 kW
5	Washing machine	1	1,000 W	1.00 kW
6	Microwave oven	1	1,500 W	1.50 kW
7	Geysers	2	2,000 W	4.00 kW
8	Split ACs	3	1,500 W	4.50 kW
9	Kitchen appliances and other sockets	—	Allowance	2.00 kW
	Total illustrative connected load			14.10 kW

The actual connected load may be higher or lower depending on the appliance ratings.

What does this mean for the electrical supply?

At 230 V, a 14.1 kW connected load would draw approximately 61.3 A if all the loads operated simultaneously at unity power factor. Actual current depends on the appliance characteristics.

For this reason:

• The sanctioned load and supply arrangement must be verified with the electricity distribution company.
• A three-phase supply may be appropriate if required by the calculated demand and applicable supply conditions.
• If three-phase supply is provided, the circuits must be distributed across phases to balance the load.
• The main cable and protection devices must be selected using a proper demand and fault-current calculation.

Do not assume that a 40A single-phase supply is sufficient merely because the property is 100 gaj.

---

6. Approximate Electrical Wiring Cost Estimate

The following is an indicative budgeting estimate for Delhi/NCR. Prices are approximate allowances, not verified quotations from electrical contractors or manufacturers.

Sr. No.	Description	Estimated amount
1	Copper FRLS wires of various sizes	₹65,000–₹90,000
2	PVC conduits, junction boxes and accessories	₹12,000–₹20,000
3	Modular switches, sockets and switch plates	₹20,000–₹40,000
4	Distribution board, MCBs, RCCB/RCBOs, isolators and SPD	₹15,000–₹30,000
5	Earthing system and protective earth wiring	₹8,000–₹18,000
6	Fan boxes, connectors, lugs and miscellaneous accessories	₹5,000–₹10,000
7	Electrical installation and wiring labour	₹35,000–₹55,000
8	Chasing, conduit laying and basic plaster repairs	₹10,000–₹20,000
	Estimated total	₹1,70,000–₹2,83,000

Recommended budget

For preliminary financial planning, keep a budget of approximately ₹2.25 lakh for the complete basic electrical wiring installation.

The estimate assumes ordinary modular accessories and standard-quality materials. Premium switchgear, additional AC circuits, concealed ceiling work, extensive civil repairs, decorative lighting and other special requirements may increase the cost.

Items not included

The above estimate excludes:

• Purchase of air conditioners, geysers, fans and other appliances.
• Decorative lights, chandeliers and premium LED fixtures.
• Inverter, battery and solar installation.
• Smart-home automation.
• Electrical meter and utility connection charges.
• Major plastering, painting and structural repairs.
• Additional floors, external landscaping or garden lighting.
• GST where applicable to the contractor's quotation.

Before approving a contractor's estimate, obtain a detailed bill of quantities with make, model, wire length, accessories, labour rates and GST clearly identified.

---

7. Recommended Circuit Schedule

For better reliability and easier fault finding, avoid putting all appliances on a few common circuits.

Circuit	Description	Wiring provision
C1	Living room and bedroom lights	1.5 mm² copper
C2	Remaining lights and fans	1.5 mm² copper
C3	General sockets in bedrooms	2.5 mm² copper
C4	Living room and TV sockets	2.5 mm² copper
C5	Kitchen general sockets	2.5 mm² copper, subject to load
C6	Refrigerator	Dedicated circuit, where appropriate
C7	Washing machine	Dedicated circuit
C8	Microwave and heavy kitchen appliances	Separate circuits as required
C9	AC in bedroom 1	Dedicated circuit
C10	AC in bedroom 2	Dedicated circuit
C11	AC in bedroom 3/living room	Dedicated circuit
C12	Geyser in bathroom 1	Dedicated circuit
C13	Geyser in bathroom 2	Dedicated circuit
C14	Spare circuit	Provision for future requirements

The final circuit arrangement may be revised to suit the room layout, connected load and the applicable installation standards.

8. Engineering Checks Before Handover

Before the installation is energised, ensure that the contractor carries out and documents the following checks:

1. Insulation resistance test: Verify insulation integrity of the installed circuits.
2. Continuity test: Verify continuity of protective conductors and other required conductors.
3. Polarity test: Confirm correct phase and neutral connections at outlets and switches.
4. Earthing verification: Check protective earthing continuity and the earthing system's effectiveness.
5. RCCB/RCBO testing: Verify operation using suitable test equipment.
6. Load and voltage-drop verification: Confirm that conductors and protective devices are suitable for actual loads and circuit lengths.
7. DB labelling: Label each circuit clearly for future maintenance.
8. As-built drawing: Obtain the final wiring layout and circuit schedule from the contractor.

The applicable verification requirements should be followed under IS 732 and the relevant electrical safety regulations. BIS

---

9. Disclaimer

This estimate is prepared for preliminary budgeting and planning purposes only. The quantities, wire sizes, circuit arrangements, equipment ratings and costs are indicative and are based on assumed requirements for a typical 100 gaj residential house.

The final design and estimate must be prepared or verified by a competent electrical engineer after inspecting the property, confirming the actual floor plan, appliance nameplate ratings, sanctioned load, supply type, cable routing, installation conditions and applicable statutory requirements.

All electrical work must be carried out by an appropriately licensed electrical contractor, with suitable testing and verification before energisation. Wire sizes and protective-device ratings must not be finalised solely on the basis of this estimate. The actual cost will depend on prevailing material prices, brands, site conditions, labour rates, taxes and the final scope of work.

This document is not a substitute for a site-specific electrical design, approved drawings or a certified electrical safety inspection.