The Total Estimated Cost Of Building A 4 Bedroom Duplex Apartment In Nigeria.

This article emphasizes the cost of building a duplex in Nigeria. The essence of the article is to give builders insights on costs associated with construction. Most times, the property owner hardly knows anything going on with his/her structure other than coming to inspect its progress

What are the benefits of building a duplex?

Well designed 4 bedroom duplex apartment

By the very nature of duplex house designs, they create an ambience that supports comfort, privacy and luxury.

Duplex accommodation in Nigeria have some common features which include:

1. Kitchen on the ground floor

2. Dining area on the ground floor

3. Guest room on the ground floor

4. Visitor’s toilet on the ground floor

5. Family bedrooms on the first floor

6. Laundry room on the first floor and

7. Family lounge on the first floor

From the list of the common features of duplex houses listed above, one thing is clear, everything that relates to the family happens on the upper floor where no visitors are allowed. This means that duplex home designs provides complete privacy.

Moving forward to the topic of discussion, it may cost you more or less when building your own duplex in Nigeria as a result of the various factors listed above. However, below is the estimated cost for a standard 4 bedroom duplex in Nigeria.

Cost of Building a Duplex in Nigeria

Before you start the foundation of the house, make sure you have all the required APPROVED documents for the construction process.

1. Architectural drawings.

2. Structural drawings.

3. Mechanical drawings.

4. Electrical drawings.

Don’t do anything about building without any of the aforementioned point above.

In calculating the cost of building a duplex in Nigeria, it is advisable to breakdown the construction process into stages. This is the norm and is actually helpful in planning your progress. For a duplex, the construction stages can be split into the following:

  • Foundation / Soak-away Stage.
  • DPC to lintel level/ground floor Stage.
  • First floor/decking stage.
  • Staircase Stage.
  • First-floor lintel stage.
  • Roofing Stage.
  • Plastering / Finishing Stage.

Cost of Foundation / Soak-away Stage.

This is the first stage of construction and it includes setting out, digging, concrete work, block laying, backfilling and flooring as the processes in this stage. Furthermore, the cost of this stage differs with respect to the soil condition.

Material Requirements for Setting-out with profiles

4 pieces of 1 x 12 plank @ NGN 1,200 each plus NGN 800 (for dividing each into 5 (@ NGN 200 each) = NGN 5,600

4 bundles of Pegs @ NGN 1,200 each = NGN 4,800

2″ and 3″ Nails = NGN 1,200 worth of nails

4 bundles of rope @ NGN 200 each = NGN 800

Labour = NGN 5,000

Estimated cost of the aforementioned materials = NGN 17,400.

Material Requirements for Digging / Excavation

Some diggers and shovels will be needed for the job. These tools can cost about NGN 2,000 to rent.

Labour = NGN 10,000

Estimated cost of digging = NGN 12,000.

Material Requirements for Concrete Columns

The duplex design affects the cost of this section as this cost is determined by the number of columns in the design. The structural drawing plays a key role in this section, as it indicates the number and design clearly. For the basis of this calculation, we have earlier said we are using a 4 bedroom duplex. Hence, the number of columns in this design amounts to twenty-two (22) nos.

The standard column dimension is 350mm by 350mm by 3000mm (height).

For constructing one column (standard mix ratio 1: 3: 6 comprising cement, sand, aggregate), you need the following materials below for 22 nos concrete column:

35 bags of cement @ NGN 2,600 each = NGN 91,000

5 tonnes of sand = NGN 10,750

20 tonnes of granite = NGN 100,000

1 tonne 12mm steel Reinforcements = NGN 170,000

Some diggers, pans, and shovels will be needed for the job. These tools can cost about NGN 5,000 to rent.

Labour = NGN 90,000

Estimated cost of concrete columns = NGN 466,750.

Material Requirements for Concrete work / Blinding

For a standard foundation of 150 mm base-thickness, assuming 0.45 m (breadth or height) and 85.5 m (entire length) = 5.77125 m3

bags of cement @ NGN 2,600 each = NGN 52,000

20 tonnes of sand x 2 = NGN 80,000

20 tonnes of Granite = NGN 100,000

We don’t need reinforcements (Iron bars) because the soil is good, firm and dry.

Liters of water as needed.

Labour = NGN 25,000

Estimated cost of concrete work = NGN 257,000.

Material Requirements for Laying Foundation Blocks

Using 9-inch blocks and laying 4 coaches, you will need

12 bags of cement @ NGN 2,600 each = NGN 31,200

644 pieces of 9-inch vibrated blocks (including 10 percent wastage) @ NGN 170 each = NGN 109,480

Plumbing work = NGN 25,000

The remaining sand from concrete work will be used here.

Labour = NGN 35,000

Estimated cost of laying foundation blocks = NGN 200,680.

Material Requirements for Filling

I suggest digging the soak-away and septic tank alongside making the foundation so that the soil dug-up from the soak-away pit, septic tank and well can be used for filling the foundation. This will save you the cost of buying some trips of sand for foundation filling, and also save you the cost of clearing the dug-up soil in a case where it is not used for filling.

After filling the foundation, water it for about 10 hours and leave it for days (or some weeks) before flooring for natural compaction. In the end, you might need to buy just a few trips of sand if the soil dug-up from the well and septic tank is not enough.

Lets Assume you buy:

3 trips of 20 tonnes laterite (fairly clayey) at NGN 18,000 = NGN 54,000

Labour = NGN 10,000

Estimated cost of filling foundation = NGN 64,000

Material Requirements for Foundation Casting / Flooring

25 bags of cement @ NGN 2,600 = NGN 65,000

Waterproof / nylon = NGN 15,000

Remaining granite and sand from concrete work will be used here.

Labour = NGN 18,000

Estimated cost of flooring = NGN 98,000

Material Requirements for Septic Tank, Soak-away pit and Well

The septic tank, soak-away pit, and well should be constructed first in order to have water for the work and sand for filling the foundation later.

700 pieces of 6-inch vibrated blocks @ NGN 150 / block (for a septic tank of 3m x 3m x 3m) = NGN 105,000.

22 bags of cement @ NGN 2,600 = NGN 57,200 (including plastering).

Number of well-rings as required.

Sand and granite from concrete work will be used here.

Labor for septic tank, soak-away pit and well = NGN 80,000

Estimated cost of constructing both the septic tank, soak-away and well = NGN 242,200.

Total Estimated Cost for this stage = NGN 1,272,030 (excluding the cost of well rings).

Cost of Construction From Damp Proof Course (D.P.C) To Lintel Level

This is the next stage in the construction process and begins where the German floor ends. It covers the main block work including wall partitions for the various spaces in the house. The materials listed below are just estimates of what you get in a modest 3-bedroom flat. Again, ensure you get a Bill of Quantities for your building plan as that’s the only way to know the exact material requirements for your house. This stage ends at the roof level.

Material Requirements and Labour for Block work

2100pcs of 6-inch stone dust vibrated blocks @ NGN 150 = NGN 315,000.

(The cost increases when you use 9-inch blocks)

15 tonnes of sharp sand = NGN 40,000

30 bags of cement @ NGN 2,600 = NGN 78,000

Labour = NGN 120,000

Estimated cost of block work = NGN 553,000. (This includes the two coaches of blocks after lintel)

Material Requirement for Lintel Casting

20 length of 12mm rod @ NGN 2,100 / length = NGN 42,000

10 length of stirrups @ NGN 500 / length = NGN 5,000

35 length of 1 x 12 x 18 wood @ NGN 1,700 / length = NGN 59,500

Nails plus wire for binding = NGN 13,000

8 bags of cement @ NGN 2,600 = NGN 20,800

Remaining sand will be used here.

Remaining granite from concrete work is used.

Labour plus carpenter = NGN 30,000

Estimated cost of the lintel level = NGN 170,300

Estimated Total Cost for this stage = NGN 723,300.

Cost of First Floor Decking Stage

For this stage, we would require the total floor area in cubic meters since there is a depth to it. The floor is 6 inches (150mm) thick. The total cubic meter for the used floor plan is 39.6 cubic meters. Hence, the cost of the reinforced concrete floor slab with ratio 1:2:4 is as follows:

Here you would need the following:

  • Bamboo
  • Cement
  • Sand
  • Granite
  • Reinforcements
  • wood

It is a long process of calculating so I have broken this down to arrive at the cost below.

NGN 25,000 per cubic meter for 39.6 cubic meters = NGN 990,000.

Estimated Total Cost for this stage = NGN 990,000.

Cost of Staircase Stage

For this stage, we would require the total floor area in cubic meters since there is a depth to it. The floor is 6 inches (150mm) thick. The total cubic meter for the staircase is 3 cubic meters. Hence, the cost of the reinforced concrete floor slab with ratio 1:2:4 is as follows:

Here you would need the following:

  • Cement
  • Sand
  • Granite
  • Reinforcements
  • wood

It is a long process of calculating so I have broken this down to arrive at the cost below.

NGN 25,000 per cubic meter for 3 cubic meters = NGN 75,000.

Estimated Total Cost for this stage = NGN 75,000.

Cost of Construction From First Floor To Lintel Level

This stage covers the main block work including wall partitions for the various spaces in the house. The materials listed below are just estimates of what you get in a modest 4-bedroom duplex. Again, ensure you get a Bill of Quantities for your building plan as that’s the only way to know the exact material requirements for your house. This stage ends at the roof level.

Material Requirements and Labour for Block work

2100pcs of 6-inch stone dust vibrated blocks @ NGN 150 = NGN 315,000.

(The cost increases when you use 9-inch blocks)

15 tonnes of sharp sand = NGN 40,000

30 bags of cement @ NGN 2,600 = NGN 78,000

Labour = NGN 120,000

Estimated cost of block work = NGN 553,000. (This includes the two coaches of blocks after lintel)

Material Requirement for Lintel Casting

20 length of 12mm rod @ NGN 2,100 / length = NGN 42,000

10 length of stirrups @ NGN 500 / length = NGN 5,000

35 length of 1 x 12 x 18 wood @ NGN 1,700 / length = NGN 59,500

Nails plus wire for binding = NGN 13,000

8 bags of cement @ NGN 2,600 = NGN 20,800

Remaining sand will be used here.

Remaining granite from concrete work is used.

Labour plus carpenter = NGN 30,000

Estimated cost of the lintel level = NGN 170,300

Estimated Total Cost for this stage = NGN 723,300.

Cost of Roofing Duplex Stage

The cost of roofing varies greatly with the type of roofing materials and design you choose to use. The cost given below represents 0.45 mm thick aluminum roofing sheets. The true cost of all stages still remains that shown on the bill of quantity document.

Material Requirements for Roofing

320 length of 2 x 3 x 12 wood @ NGN 450 = NGN 144,000

45 length of 2 x 6 x 12 @ NGN 840 = NGN 38,250

25 length of 1 x 12 x 12 wood @ NGN 1,400 = NGN 35,000

1/2 bag of 2-inch nails @ NGN 5,800 = NGN 2,900

11/2 bags of 3-inch nails @ NGN 6,000 = NGN 9,000

1/2 bag of 4-inch nails @ NGN 6,500 = NGN 3,250

Aluminium (0.45mm thick) roofing, transportation and Labour = NGN 685,900

Total Estimated Cost for the roofing stage = NGN 918,300.

Cost of Finishing Stage

This stage includes plastering, wiring, plumbing, fixing of windows, doors, tiles, and other essentials. The cost here varies with respect to the quality of materials you use. Below is an estimate for a very modest finishing.

Material Requirements for Electrical works

Wires, Pipes, Conduit Boxes, etc = NGN 400,000

Material Requirements for Mechanical and Plumbing Works

Kitchen sink, Pipes, WC, Washing Hand Basin, Overhead Tank, Shower, etc = NGN 500,000

Material Requirements for Ceiling

Woods for nogging, P.O.P Sheets, External wood finishing, P.V.C Boards, Tank nails, etc plus labor = NGN 450,000

Material Requirements for Windows and Doors

Windows, doors, burglary proof, and fixtures plus labor = NGN 1,500,000

Material Requirements for Wall Rendering and Painting

Plastering and painting plus labor = NGN 1,500,000

Material Requirements for Floor Finishes

Tiles and others plus labor = NGN 1,000,000

Estimated Total Cost for this stage = NGN 5,350,000.

Grand Total = NGN 1,272,030 + NGN 723,300 + NGN 990,000 + NGN 75,000 + NGN 723,300 + NGN 918,300 + NGN 4,350,000 = NGN 10,051,930

The Total Cost Of Building 4bedroom Duplex

As you can see from the calculations, we arrived at a total cost of building a 4 bedroom duplex which is a little above NGN 10,000,000. To Build a standard duplex in Nigeria one is expected to have between N10 million to 20 million Naira.

Conclusion

The design is a very simple one with an aesthetically conscious approach. For more complicated designs, the cost could exceed what we have calculated above. As for the furniture fittings, you have a variety of options you can choose from.

Thanks for your time, incase of any mistakes don’t hesitate to correct us on the comment section and you can educate others by sharing this on.

Building A House: 14 Stages of Building a House in Nigeria

Building A House: 14 Stages of Building a House in Nigeria

Building a house in Nigeria is a very big challenge and big achievement, that is the reason even the low class and the jobless will always wish to have one, however, it is good to know that having a house is a very good thing.

In this post we are going to teach or rather un-vail the various stages of building a house once you have a landed property. This is to encourage our readers to know what to do and how to start the journey of having their own house.

So many people want to know the stages of building a house in Nigeria. Some professionals argue over time that this information doesn’t concern non-professionals but I disagree. As a buildee, you also need to know the stages of building a house in Nigeria.

This informs some decisions you get to take as regards your project. Especially in the aspect of finance and also, choice of vendors. However, a program of works is usually prepared by the contractor showing you these details. When to start the tiling works, how long it would take, etc.

In this article, we have taken out time to elaborate on the stages of building a house in Nigeria. This is a step-by-step guide just so you, the owner, also know what precedes each stage of the construction.

1. Paperwork

Stages of Building a house in Nigeria Before you start your construction project, you need to have the right papers. Not just the right papers, but the right APPROVED papers. This includes drawings from all the professionals involved in the design of your structure. The paperwork includes the following listed below, but not limited to:Architectural Drawings, Structural Drawings and Bills of Quantities (Includes material and labor cost, contingencies, etc)

2. Setting Out


Stages of Building a House in Nigeria
The next step is to mark the boundaries of the property on the ground. We term this setting-out. We do this to define accurately, the outline and width of excavation. It also aids in the centerline determination of the building walls as proposed. The major aim of this process is to transfer the working drawings on paper to the ground.

3. Trench Excavation


Stages of Building a House in Nigeria
Excavation is carried out as the next step. This involves digging trenches to receive the foundation of the structure. Regarding the drawing’s defined lengths and widths, excavation should be carried out. Depending on the depth and composition of the subsurface, suitable machines are used to excavate the earth. For regularly smaller structures, we use manual digging tools.

4 Foundation Work

Foundation work comprises many sub works which include:

i. Compacting the ground
The excavation pits are trimmed and dressed as per the structural Engineer’s given details. Hand compactors are used to compact the soil base.

ii. PCC
PCC stands for plain cement concrete, which is sometimes called “Blinding”. This is done to have a level surface, thus forming a solid base on which reinforcements can be tied. This enables the placement of a concrete footing. Plain cement concrete of the mix 1:4:8 cement, sand, and aggregates. It could also be a ratio 1:3:6 and laid on the compacted soil in varying depth as required.

iii. Footing Reinforcement
Reinforcement steel bars are tied together and placed on the PCC to form a skeleton in which concrete is poured and the column rods are taken from them.

iv. Shuttering
To achieve a properly shaped concrete, shuttering is done as per section details in the drawing. It is also done so that the concrete doesn’t come in contact with the soil.

v. Footing Concrete
It is very necessary to check the levels of foundation before concrete work. There are patches where excavated depth slightly exceeds and vice versa. Concrete is poured as per structural drawing specifications.

5 Column Casting

Regardless of the structure being constructed, columns are advised to be used. In this modern-day, framed structures are springing up, with columns, beams, and slabs offering designers the room to play with walls. This doesn’t negate the role of load-bearing walls though, except for lack of flexibility. Column casting is next and is made by pouring concrete into frameworks already fixed and shuttered. Columns are ready after curing takes place over a 24hr period.

6 Floor Casting

Some people cast their floors before columns sometimes. However, this is usually for a single floor structure. When dealing with multiple floors, it is right to cast the columns first.

7 Laying of Block Walls

Block walls are next on the process list. These walls could be constructed using materials such as bricks, wood, precast concrete, solid/hollow blocks, glass. The use of some of these materials is greatly affected by the construction method. The height of the walls depends on the floor height. Necessary openings are created for doors, windows, and ventilators.

8 Lintel Casting

This is not really a stage per se, as it is done during the laying of block walls. A lintel is a horizontal support across an opening. It could be a door or window opening. Openings for windows & doors are left during masonry works. Lintel could be made of reinforced cement concrete, timber, or steel, and is design dependent. The lintel is created to carry loads above the opening.

9 Roofing

Roof members (king post, tie beam, purlins, etc) are set up to receive the roof covering. The roof members also depend on the roof covering material. Some roof members could be made of steel sometimes. When you talk about the stages of building a house in Nigeria, this is a milestone stage.

10 Plastering Work

Plasterwork begins after taking off the formwork, over a 14-day period. Mortar for plasterwork is of the mix ratio 1:3 or 1:4 cement and sand. The thickness of the plaster layer should not be over 0.75 inches. Curing takes about 7 days to make the plaster gain proper strength.

11 Fixing of Doors and Windows

At this stage, you can fix doors of various materials depending on the specifications given. Wooden doors are the most preferred type but sometimes, doors made from aluminum and steel are used. All doors should have sufficient fire ratings. This is the standard. For the windows, you could have wooden windows, aluminum casement/sliding windows, projected windows, etc. It is safer to fix doors after the first coat of painting works.

12 Fixing of Electrical and Plumbing Works

The necessary electrical and plumbing works are carried out before the final finishing works. These electrical works do not start here, especially when conduit wiring is preferred. All of the conduit pipes would have been laid during the casting of the floor. Finishing works such as painting and laying of tiles are done after fixing these components to reduce the damage.

13 fixing of Tiles
Stages of Building a House in Nigeria
Here, tiles are laid in specific areas as shown in the specification drawings. Areas such as bedrooms, bathrooms, kitchen, are usually tiled even though it is at the request of the client. First, the wall tiles are fixed after which the floor tiles come next. For flooring works, some materials used also include granite, marble, epoxy.

14 Painting
Stages of Building a House in Nigeria
Painting comprises different sequences depending upon the finish required. It could be 1 coat of primer and 2 coats of water-based paint done. Also, could be 2 coats of putty and 2 coats of paint, done for a smooth finish. It defers for outside and inside works.

Note: After all this steps there must be a miscellaneous Works which includes terrace waterproofing
landscaping works
False Ceiling
Installation of Furniture
At various intervals, miscellaneous works take place. Some of them could be an after-thought which will require the undoing of some previous work. This causes a lag in delivery time. It is pertinent to plan out all that is required for a project. This is to make sure you do not lose valuable time and money.

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