The dream of every man is to own his home. May the good Lord let us all achieve that. Amen

It is important for one to be able to control cost in whatever project one is undertaking. This is one of the underlying principles of project management. How effectively you can manage cost vs time, resources vs output will determine whether you will be able to meet that deadline with your scheduled price.

A construction team consist essentially of a

*Surveyor
*Architect
*Geotechnical Engineer
*Structural Engineer
*Quantity Surveyor
*Project Manager/Contractor
Each person has a well defined function and professional trespassing is a moral crime.

In summary, the surveyor is the one in charge of making site layout and installing beacons/corner piece, and performing setting out. The Architect is the one to design the building, bringing it out from emptiness..in all its beauty and grandeur. He will conclude with an architectural drawing showing the floor plan, elevations, sections, doors/window schedule, etc.

Next is the geotechnical Engineer. He will visit the site, make appropriate tests on the soil and conclude with a result on the type of soil, the bearing capacity, the recommended foundation and wether the soil can support the house intended.

Next, the structural engineer comes in, gallantly. Merging both the architectural drawing and the soil test result from the geotechnical don, he designs the building structurally. He analyses the building for loads combination, stability, flow of stress etc and decide the components for the building. He concludes with a working drawing showing Foundation plan, foundation details, column, beams, slab, walls, staircase etc.

Note that in many cases, either the architect/structural engineer is free to design for aestethitcal components eg...finishes, tiles, pop,, landscaping etc.
The mechanical/electrical engineers prepare their schedules of mechanical components/electrical fittings.

Next is me , the Quantity Surveyor. No one, I repeat, no one knows about estimating materials, quantities, price of a structure and it's materials better than a QS. The QS estimates, technically, step by step process in the construction process and concludes with the PRICE of the project.

The project manager is in charge of keeping everyone on track. He controls the spending of money and materials and has a perpetual vision of when the project should be completed.

Now that you have a brief overview, we can move on to the topic gangan.

Phases in a simple construction

The QS estimates cost of a building phase by phase. We shall be going through each of the following phase one after the other till we complete the project. NB: Every information you learn online is not a replacement to employing the service of an actual professional. It is for you to learn, and be guided. Let's go!

The following are phases of a building construction measured by a QS:

A. SUBSTRUCTURE
1. Site Clearance
2. Top Soil Excavation
3. Excavation of foundation trench (Strip)
4. Levelling/Compacting Base of Excavation
5. Excavation of column base pit (pad)
6. Concrete Blinding
7. Concrete in foundation
8. Column base: Concrete, Reinforcement, formwork
9. Block work in foundation
10. Backfilling and Disposal
11. Filling of laterite
12. Filling of Hardcore
13. Stone Chippings/River sand
14. DPM in oversite concrete/German floor
15. BRC mesh Reinforcement
16. Concrete in floor

*optional: piping to extract water, anti-termite treatment etc.

PHASE B. FRAMEWORK
1. Columns: Concrete, Steel, formwork
2. Attached Beams: Concrete, Steel, formwork
3. Slabs: Concrete, Steel formwork
4. Shear Walls: Concrete, Steel, formwork
5. Staircase: Concrete, Steel, formwork

C. BLOCKWORK
1. Block in walls
2. Lintel: Concrete, Steel, formwork
3. RoofBeam: Concrete: Steel, formwork

D. ROOFING
1. Concrete fascia: Concrete, Steel, formwork
2. Roof Gutter: Concrete, Steel, formwork
3. *Wall plate (not compulsory)
4. Tie Beam
5. KingPost
6. Rafter
7. Struts
8. Purlins
9. Noggins
10. Roofing sheet
11. Eave angle, Valley piece, Ridge Capping, Fascial Flashing, etc

E. Waterproofing Works in Roof

F. FINISHES
1. Floor Screeding
2. Rendering: slab, staircase, columns
3. Tiles
4. Skirting
5. Wall Plastering
6. Wall tiles
7. Door/Window Jambs
8. POP Screening
9. POP Cornices
10. Windowhood
11. Wall Skirting
12. Crack Tiles
13. Balustrades/Railings

G. DOORS/WINDOWS
1. Door/Window Quantities
2. Burglary
3. Accessories

H. MECHANICAL INSTALLATIONS
I. ELECTRICAL INSTALLATIONS
J. AC INSTALLATIONS

K. PAINTING
1. Internal walls
2. Externally walls
3. Doors/Windows
4. Door/Window Jambs

Cc: Lalasticlala, we are going on s long ride.

A.1 Site Clearance

This is the first item you measure. From the architectural drawing, get the square metre of your land and multiply with the current rate in your locality.

Rates vary from place to place, and varies by nature of the land. Rate of clearance for a grassy land will be different from that of a bushy one, and even one that contains rocks that need to be blasted. So get the length (longer side) and multiply by width ..from the (foundation plan in structural drawing - 1st choice) or from the floor plan in the architectural drawings - 2nd choice. This is easy, right?

2. Top soil excavation.
Usually nowadays, people rent tractors for clearing the land which also removes top soil at the same time. Top soil is the vegetable layer on top . it is usually removed to a depth of around150mm - 175mm normal scenario. The rate is between 15000 - 50000 depending on your location per plot.

Keep it coming

3. Excavation of Trench

After you have must have removed the top soil. The next thing is for the surveyors to come in and do the setting out. Usually in billing, we allocate a lump sum to that. As it is not measurable. The price of setting out varies from area to area and depends on how big or complex your building is. Most surveyors charge by plot. I would not want to mention a specific rate.

The next measurable phase is excavation of trench. How do you calculate for this?
It is a volume measurement billed in cubic metre (l*w*d)

Now the depth of excavation is gotten from the structural drawing (specifically foundation details). Sometimes the depth includes column base depth, sometimes it doesn't. You have to read that from the drawing. It is usually 0.6m - 1.5m for simple strip.

The width of your trench depends on the size of block you want to use. Is it 9" or 6"? If the drawing specifies 9" then the width is 675mm otherwise it is 450mm.

Then the length of trench. This is where you need to get your main girth (total length of all walls). Now getting this is a bit tricky and if you are not well trained you may read an excess of about 10-20m. You have to take the structural drawing showing the foundation plan...and read the length of all walls. Both Internal and external walls.

Most people erroneously use the ground floor plan in the architectural drawings to read the girth. This is a big mistake as not all wals in a building is founded from the trench eg some toilet and partition walls.

Also be careful when reading length, a trick of the trade is to measure horizontal in-in, vertical out-out.

If your whole length is say 98m, your depth is say 0.6m and your width is say 0.675m then total volume of excavation is 98 * 0.6 * 0.68. Whatever it gives you multiplied by the current rate per m3 is the amount you will set aside for trench excavation.

Excavation of column base pit

Most often than not, buildings are supported by columns. And these columns are founded in a pit in the foundation. From the foundation details, you will see the drawing of column bases usually titled as base type 1 (BT1), base type 2 (BT2) etc. The plan and elevation are shown together.

So you will read the length and width from the plan and read the depth from the elevation. You will multiply the three together and multiply by the number of that particular base type to get the volume of soil that will be excavated for column base. This will be repeated for all the base types. Then you will add all together and multiply by the rate (same with trench excavation rate).

One thing to note here is that in some drawings, the level of the column base and that of the trench are the same, while in others, they are not the same. So be careful not to increase your money unnecessarily.


Levelling and compacting bottom of excavation

While calculating for trench excavation, you got a value for total length of all walls. Keep that value safe, we will make refence to it. And I'll refer to it as the Main Girth.

Now after the trench is excavated, the next logical step is to prepare the base of the trench to receive Blinding. This is measured separately. You multiply the main girth by the width of trench and add it to the multiplication of length and width of all column base. This value is in square metre.

You then multiply by the rate to get the amount.

Good Job

phemmy88:
Good Job

Thanks Sir..

Concrete Blinding

Now that you have prepared the base of your trench, the next step in any foundation is to do the Blinding. This Blinding is usually around 50mm thickness. So rule of thumb, concrete work less than 10cm thickness is calculated and measured in square meter (as against cubic meter, for standard volume).

So multiply the value of your main girth by the width of your trench and add to to the area of all column base. Whatever your answer is, multiply by the rate (presently around N300 - N1000) to get the amount you will set aside for Blinding work.

Column Base Calculations

Now that Blinding is ready, we can proceed to placing of our column bases. But how much do we set aside for Reinforcement, formwork and concrete? How do we know our contractor is honest with us?

Here we go..logically... Reinforcement (basket), Reinforcement (starter bars), formwork, concrete.

Basket.
From your foundation details , you will see the plan of each base type showing the different steel in the base. And the length and width of each base type.

Now for the length side, check the steel provided. Eg if it is 9Y1601-200c/c btm, that means you have 9 numbers of 16diameter Reinforcement with bar mark 1, laid with spacing of 200mm each one. So you will check the length, say 1.3m. Allow for concrete cover, say 50mm each end. Then length of each Y16 will be 1.3m - 0.1m = 1.2m then multiply by 9 = 10.8m this is the amount needed for length side. Do the same for width side.

Say you got around 22m for the basket, then do for all base type and add all, then save your answer somewhere.

[B]starter bars [/b]

Now check the section drawing of your foundation detail for starter bar calculation. You will see the length of the starter bar in each one. For the bend, you can allow 300mm or 16*bar diameter, whichever is larger. Multiply by the number of bars you have. Let's say you have 4y16. And length of each starter bar is 1.2m. Allow 300mm for bend, that gives 1.5m

Multiply by 4.. Equals 6m. Now do for all the base types and add together.

If the starter bars and the bars in the base are of the same type, you can add together to get a value. If not you can't. Let's say they are both y16. For our example then we have 22m + 6m = 28m. Let's say we have 6 column bases = 168m.

So for billing, it is preferably to Bill by weight, so you convert the metre to kg by using the unit weight of each steel type. Let's say that value for y16 is 1.579kg/m.

Therefore 168m = 265.27kg. Multiply by the rate (say N275) and you have the amount for your Reinforcement.

Links in starter bars

Our calculation for Reinforcement is not complete. The standing starter bars will not just stand Na. They will be joined by stirrups (links) and we have to calculate the amount needed for the links too.

Where can you see the links? They are also shown in the foundation details. In the same drawing you saw the starter bars... Links are usually Y10. When you check the section of your stub column, you will see something like 22Y1003-150c/c pointing to a vertical line spanning from the top of the base to the top of the column.

The same procedure we used in calculating the previous steel but with a little twist. How do we know the length of each link?

Let's say the stub column dimension is 225mm * 225mm
That's is 0.23m by 0.23m. Let's allow 25mm for cover in all beams and columns.
That means length of one side equals 0.23 - (2* 0.025) = 0.18m. Multiply by the four sides to get 0.18*4 = 0.72m.

Now allow 150mm or so for hook...that is 0.72 + 0.15 = 0.87m so this is the length for one link.

Multiy by 22 to get the length of all links...that is equal to 19.14m.

To weight, multiply by unit weight. (Let's assume 0.616 for Y10). Therefore 19.14m = 11.79kg. Now check for all the stub columns and get your final value.

Multiply by rate to get your amount....!

After the Reinforcement is fixed, then formwork should be fixed before casting. Calculating amount of formwork is easy.

Get the perimeter of your column base. Perimeter, not Area. That's 2(length + width). Then multiply by the depth as seen in the section drawing. That will give you the area of the formwork. Now get for each base and add all values together. Whatever your final value is, multiply by the current rate (say N300) to get the amount needed for all formwork.

Concrete in Foundation
A. Concrete in pad.
For each base type, multiply the length * width * depth to get the volume of concrete needed. Do this for all bas types to get total amount of concrete needed in pad base.

The multiply the length of the column starter by the width by the specified height (as seen in drawing) and get the values for all column starters.

B. Concrete base in strip.
Usually, most structural engineers specify having a strip of concrete in the trench before starting blockwork. This is usually 225mm thickness.

To know if your building needs this, check your structural drawings (foundation details). If indicated, then you know you have to set money aside for this too.
So multiply your main girth by width of your trench by thickness of concrete to get the cubic meter of your concrete.
Add this value to the one you got for concrete in pad; this is the total amount of concrete you need exactly in your foundation.
You can do well to allow 5-10% for wastage.
After getting final value, then multiply by the current rate of concrete work (say N26000 -N29000) to get the amount needed for all concrete in foundation.

Blockwork

Moving on. After you've cast your column bases, columns and concrete base in strip, you are set for blockwork in foundation. But how do we know the amount of block needed in foundation?

Your main girth comes in again.
First, we need to get the area of the place where block is needed. Now add the LENGTH of all columns together and deduct from the main girth. Then multiply this value by (height of trench - height of concrete strip).

Eg. If your original trench depth is 1m. And the height of your column strip is 0.23m, then the net height of block work is 0.77m

If your main girth is say 97m. And you have 6nunbers of 225mm by 225mm columns, then the net length of your blockwork is 97 - 6(0.23) is 95.62m

Net area of block work is 95.62 *0.77 = 73.63m2.

Now 1 square meter = 10 blocks.
Therefore 73.63m2 = 736.3 blocks.

Allow 5% for breakage , 736 + 5% = 773 blocks needed.

Although in billing, we actually use the square meter.
So if a square meter of block work equals say (3600naira), you multiply by 74 square meter to get the amount needed for block work.

Backfilling and Disposal

So after completing blockork and waiting for it to set, next now is to call labourers to fill the remaining spaces in the trench and level it up. But how do you know the amount everything costs?

We need length, widht, depth.

Length is your main girth as calculated.

Width - you subtract the width of your block from the width of the trench. Say your trench is 450mm wide and you are using 6" block...then the remaining width is 450mm - 150mm = 0.3m

Depth, you subtract the depth of the concrete work in trench from the depth of the trench.

Now length * width * depth = volume of soil to be backfilled. Multiply this cubic metre by the current rate of labourers' work to know the amount needed.

Disposal

The volume of soil excavated less the volume of soil backfilled, theoretically, will give you the volume of soil to be disposed off site.

Now depending on the nature of your site, you might not need to dispose excess Soil from your site if the soil is good. Contact your engineer for clarification.

Laterite filling /Hardcore filling

From the same drawing we have been referencing to, structural drawings/foundation details... Check the foundation detail very well..you will see something like

"250mm of imported well compacted laterite...."250mm of well compacted harccore

So how do you know the volume you need?

Open back to your foundation plan in structural drawings...then get the area of your plan. If the shape is irregular, you might need to break it down to squares, rectangles and triangles. Then use the basic formulate to get individual area and add together. Now that is the square area of your foundation.

For laterite and Hardcore respectively, multiply this square area by each depth to get the volume needed.

Convert the volume in cubic metres to Tons to get number of trips needed.

Now multiply each ton by the current rate to get the amount.

As quantity surveyors, we bill using the cubic metre directly. The rate we use will include the price for compacting, labour, offloading etc.

After these, you are now set for oversite concrete/german floor.

Keep it coming, very informative

Expose (Expozay) on construction costs.

KolaShangOne:
Expose (Expozay) on construction costs.

1Engr:
Keep it coming, very informative

endtimesblog:
Nice one op

Thank you very much sirs

Oversite Concrete/German floor

Good morning. The next and final step for substructure (foundation) is the oversite concrete. So we are ready for casting now but we need to know the amount of materials we need. First, the DPM, then the BRC mesh (usually A142), the formwork to the edge of the slab, then the concrete itself.

Note that it is not always for all building that the whole floor is cast once. In some drawing, it might be specified that an expansion joint be used (usually when the floor area is very big, or the structural engineer is trying to...I dunno sef. Not my field).
But whenever you come across an expansion joint, know that the floor will be cast according to the number of sections indicated.

1. DPM.
This is the damp proof membrane. It is used to protect the building from upsurge of water from the soil below. From your foundation plan, multiply the length by the width to get the square metre. You can add a certain percentage, say 5% to cater for tearing. So your final value multiplied by the current rate at which it is sold per square metre is the amount you will set aside.

2. BRC Mesh
Same calculation as for DPM.

3. Formwork for edge of slab.
Here we need the perimeter of our floor. So that is 2(length + width). So your value in linear metre multiplied by the rate of wood per metre is the amount needed.

4. Concrete work.
Concrete work is measured in volume (cubic metre) as you must have noticed by now. Let's assume from you foundation details (in structural drawing), it is stated that 150mm mass concrete on well compacted Hardcore, then you know the thickness of your concrete is 0.15m.

So get the area of your floor (like we did during Hardcore/laterite filling) and multiply by 0.15m to get volume of concrete needed. You can add 5% to cater for wastage. Then multiply this value by the current rate of concrete work per cubic metre (say N25000-N28500) to get amount needed for concrete work.

So congratulations, we just finished phase 1 of your building. You can now estimate amount needed to complete your substructure.

Note that these explanations is for academic purpose only. They do not replace the services of an actual professional.

Superstructure (Frame)

Engineers recommend that any building above a storey (ground floor, first floor) or any building on a Soil whose bearing capacity is less than 200KN/m2 must be supported by frames as against load bearing walls. In some scenario, a storey building on a very good Soil might still be supported by frame after thorough load analysis. Engineers strive for a balance between safe and economic. And the best decisions on structures lie with the structural engineer. Not the architect, not the Quantity survey neither the project manager nor the contractor.

So how do you know your building is supported by frame?

Open to the structural drawing and if you see columns and beams drawing. Then you have frame in your structure. So we will estimate their quantity one after the other: Column, beam, slab.

Columns

1. Reinforcement.
This is the steel in the column. Open to your structural drawing/column details. You will see the drawing of plan and section of the columns, usually labelled as col C1, col C2, col C3 etc.

Now to the first column type, C1.

Remember during foundation class, in the stub columns, we have two steel type, Y16 and Y10. Sometimes we may also have Y12 in the column.
So check your column section for all the y16 labelled. Eg 4Y1602, 4Y1603. That means we have 8 numbers of Y16 in the column. For the first one, check the length of the steel. This is usually equal to the height of that floor plus the lap length (I.e., the length of the extension above that floor where you will tie the upper steel to, usually 600mm - 1000mm).

Check the second Y16 bars length too. This is equal to that storey height. Then multiply each one by the number indicated. And add both first and second one together.

E.g. let's say in a storey column (ground floor, first floor). The height of each storey is 3150mm. And we have 4Y16 in each storey with a lap of 600mm, then the total number of Y16 needed for that column is (4* (3.15+0.6) + (4*3.15).
Equals 15 + 12.6m = 27.6m. Then multiply by the number of that column occurring and do for all column types.

Add together to get a final value and multiply by the unit weight to get the weight needed. (as steel is billed by weight).

Let's say the total length is 91m and the unit weight of Y16 is say 1.579kg/m... Then the weight needed is 91*1.579 = 142.69kg.

So if a kg of steel is say N270, then the amount needed for Y16 in columns is 270 * 142.69 = N38,526.30

For the links, we use the same procedure we use for the links in the stub column.

Formwork
To calculate formwork, we need the dimensions of the column as seen in the column section. If the dimension of the column is say 225mm * 225mm, then for the ground floor, height of column = (height of storey - thickness of beam).
So, say the thickness of beam is 450mm as seen in the column elevation (structural drawing, remember). Therefore for our example, height of column will be (3.15 - 0.45) * 2 = 5.4m.

And then area of formwork equals (0.225 *4) * 5.4m = 4.86 square metre of formwork. Then multiply for all the columns in the foundation plan and further Multiply by current rate of formwork per metre and you have the amount needed for formwork.

concrete in column

We need length, width, hheight.

Length is seen in the column section. Say 0.225m

Width is also seen as above say 0.225m

Then height is the same height as for formwork. Height of storey - thickness of beam.
For our example say (3.15 - 0.45) * 2 = 5.4m

Therefore volume of concrete needed for one column is 0.23 * 0.23 *5.4 =0.29 cubic metres.

Then multiply by all columns of the same type to get a final value. Say we have 6 numbers of 225mm * 225mm columns, final volume of concrete is 0.29 * 6 = 1.72 cubic metres.

So multiply this value by the current rate of concrete per cubic metre and you know the amount needed for concrete in columns.

I honestly loved your work and simplification, but I just think you need to attach a couple of pictures for each stage to explain to the lay man what a column or girth or DPM or formwork or slab is... that way its easier for a lay man to get the message

Very detailed and explicit tho

Ok

Typical Nigerian Will Just Ask


How Much Is Every?

Excellent but what about the use of Building and Engineering standard method of measurement known as BESMM for QS is this still allowed

Note taken

Building services engineer nko M $ E drawings as well as Bill of Engineering Measurements and Evaluation (BEME) preparation.

In some cases you will require an Environmental Engineer also. Sewage design layouts, wastewater treatment design, Cold water supply layout, etc

Head of Technicians

NLresidentQS:
The dream of every man is to own his home. May the good Lord let us all achieve that. Amen

It is important for one to be able to control cost in whatever project one is undertaking. This is one of the underlying principles of project management. How effectively you can manage cost vs time, resources vs output will determine whether you will be able to meet that deadline with your scheduled price.

A construction team consist essentially of a

*Surveyor
*Architect
*Geotechnical Engineer
*Structural Engineer
*Quantity Surveyor
*Project Manager/Contractor
Each person has a well defined function and professional trespassing is a moral crime.

In summary, the surveyor is the one in charge of making site layout and installing beacons/corner piece, and performing setting out. The Architect is the one to design the building, bringing it out from emptiness..in all its beauty and grandeur. He will conclude with an architectural drawing showing the floor plan, elevations, sections, doors/window schedule, etc.

Next is the geotechnical Engineer. He will visit the site, make appropriate tests on the soil and conclude with a result on the type of soil, the bearing capacity, the recommended foundation and wether the soil can support the house intended.

Next, the structural engineer comes in, gallantly. Merging both the architectural drawing and the soil test result from the geotechnical don, he designs the building structurally. He analyses the building for loads combination, stability, flow of stress etc and decide the components for the building. He concludes with a working drawing showing Foundation plan, foundation details, column, beams, slab, walls, staircase etc.

Note that in many cases, either the architect/structural engineer is free to design for aestethitcal components eg...finishes, tiles, pop,, landscaping etc.
The mechanical/electrical engineers prepare their schedules of mechanical components/electrical fittings.

Next is me , the Quantity Surveyor. No one, I repeat, no one knows about estimating materials, quantities, price of a structure and it's materials better than a QS. The QS estimates, technically, step by step process in the construction process and concludes with the PRICE of the project.

The project manager is in charge of keeping everyone on track. He controls the spending of money and materials and has a perpetual vision of when the project should be completed.

Now that you have a brief overview, we can move on to the topic gangan.

That construction team you highlighted up there is incomplete without a PLANNER!!!.....(which i am proud to be one)

I agree with you in everything except only QS carry out cost estimation. I put it to you that ur cost estimation is limited and more at cases just on buildings. You can never cost eatimate bridges and so on that's why it pays to be a civil (structural engineer) you can do all this I repeat all this. Morning all

NLresidentQS:
The dream of every man is to own his home. May the good Lord let us all achieve that. Amen

It is important for one to be able to control cost in whatever project one is undertaking. This is one of the underlying principles of project management. How effectively you can manage cost vs time, resources vs output will determine whether you will be able to meet that deadline with your scheduled price.

A construction team consist essentially of a

*Surveyor
*Architect
*Geotechnical Engineer
*Structural Engineer
*Quantity Surveyor
*Project Manager/Contractor
Each person has a well defined function and professional trespassing is a moral crime.

In summary, the surveyor is the one in charge of making site layout and installing beacons/corner piece, and performing setting out. The Architect is the one to design the building, bringing it out from emptiness..in all its beauty and grandeur. He will conclude with an architectural drawing showing the floor plan, elevations, sections, doors/window schedule, etc.

Next is the geotechnical Engineer. He will visit the site, make appropriate tests on the soil and conclude with a result on the type of soil, the bearing capacity, the recommended foundation and wether the soil can support the house intended.

Next, the structural engineer comes in, gallantly. Merging both the architectural drawing and the soil test result from the geotechnical don, he designs the building structurally. He analyses the building for loads combination, stability, flow of stress etc and decide the components for the building. He concludes with a working drawing showing Foundation plan, foundation details, column, beams, slab, walls, staircase etc.

Note that in many cases, either the architect/structural engineer is free to design for aestethitcal components eg...finishes, tiles, pop,, landscaping etc.
The mechanical/electrical engineers prepare their schedules of mechanical components/electrical fittings.

Next is me , the Quantity Surveyor. No one, I repeat, no one knows about estimating materials, quantities, price of a structure and it's materials better than a QS. The QS estimates, technically, step by step process in the construction process and concludes with the PRICE of the project.

The project manager is in charge of keeping everyone on track. He controls the spending of money and materials and has a perpetual vision of when the project should be completed.

Now that you have a brief overview, we can move on to the topic gangan.