Fellow Nairalanders,

I need your technical input as regards my twin duplex under construction! The calculated estimate was given as 18M-23M by a professional. I hv spent over 5M already on the foundation being adjudged to be water-logged, 100% above d estimate. I hv recently done the casting and the next stage is filling. I have been so turned off by the skyrocketting costs. The foundation is 5 boards in place of 3/4 boards with 10 tons of reinforcement! Does this change in foundation the previous estimates from the ground floor up to roofing?

See below a breakdown of future costs from the filling to roofing:

65 trips of filling sand of 20 tons + labour @25,000/trip=, 1,625,000
Concrete work(granite,sharp sand,cement,e.t.c)=, 1,500,000
Reinforcement 5 tons, N650,000
Hardcore 2 trailers, N200,000
DPC membrane(nylonlike material for stopping water from going up), N40,000
Renting of compacting machine (4days), N100,000
2 trips of sharp sand, N100,000

Soak away
Concrete for (2), N370,000
Reinforcements 2 tons, N260,000
Planks 120, 172,800
2 x3 & 2 x4, N22,500


GROUND & FIRST FLOOR
Blockwork to first floor, N1,814,400
First floor slab=1,500,000 +132,000, 1,632,000
Reinforcements 8 tons, N1,040,000
Columns concrete, N1,320,000
Reinforcements 3 tons for columns, N390,000
Lintels + Arc concrete, N184,800
Carpentary for lintels 132 planks +transport, 95,040
Carpentary for slab + beam 1005 planks, 723,600
Props (bamboo to carry first floor slab), 258,500
2 x 3 (240), 96,000
Labour for carpentary, N700,000
Nails + binding wire, N160,000

Blockwork to roof level same as g.f, N1,814,400

Roofing aluminium, 1,632,000
Carpentary for roof, 1,245,472

TOTAL=18,146,512!!!!!!! This means 23M+ already higher than estimated project cost!!

I am stunned, confused and speechless. Any encouragement and criticisms would be welcome. Thanks!!!

Advice please!!!!

the plot size is 37.7 by 18.4m. The building covers 27m by 12m. It is a 4-bedroom twin duplex with an attached BQ.

[b]Poor you, your contractor is having a field day.
A raft foundation for your kind of work shouldnt cost more than 4 million including the filling. The fillings was way overbloated.
And what does hardcore really mean? Its just some crap invented by contractors to milk the uninitiated clients. There are some special types of fillings, usually mixing the red with the light-pink ones together give you a solid stone like result after been touched by water.

This is the estimate I currently shared with a client who wanted something similar:

Foundation Explanation:
layout, rough carpentry for raft, welding and iron casting, concrete casting, filling, German floor, raft extension, and foundational plumbing and electrical work layout work.

Materials:
2 tonnes of 16mm, Cement, 20 dozens of Rings & Binding wires, 200 pieces of 10x12, 100 pieces of 12x12, 3 trucks of Granite, 2 trucks of Sharp Sand, 50 trucks of Fillings at #20,000 per 1, Water: (Digging a well), Geepee tank, Transportation of materials.

The complete total for the foundation = #3,490,000

And not a single dime would be included. The guy just messed you up with several meaningless technicalities he included in the estimate. Usually, its the kind of english home owners love to listen to but in most cases its professional ojoro. Pardon my english.
I wont get involve in this, but you call me, I can help you straighten him and tell you how to deal with him or simply get someone else:

@larimo
Just taking a cursory look at the prices given, I think you may be getting hit by your contractor.

Note that most times, prices of materials are usually not exaggerated or increased by contractors as they know you can quickly verify these prices +/-10%. The quantities are the figures which are manipulated as they know most people do not know the basis for the calculations.

Taking a look at the amount of laterite needed. Area of house is 27 X 12 = 324sqm
You stated the ground beams made use of 5 boards. Each board should be 12 inches = 0.3048m though a lot of softwood in the market used for formwork is hardly 12". I imagine some excavation must have been done also, so the 5 boards does not cover the entire volume needed to be filled. I will however discount all these and use the 0.3048m height for each board.
: Height = 0.3048 X 5 = 1.524m
Volume = 324 X 1.524 = 494 cubic meter
Add 10 or even 20% markup for wastage, shrinkage and the fact that most tippers are hardly the stated quantities. Also, some quantity will go towards filling the access route that the labourers will take to fill your building.
Required laterite volume = 494 X 1.2 = 593 cum

Each 5 ton tipper should have a volume of 3.81 cum.
20 ton = 15.24 cum

Total trips required = 593/15.24 = 39 trips as against 65 quoted.
While there might be changes based on soil conditions, I doubt if it will be almost a70% increase. Remeber also that we already added in a 20% markup.

Also, while I may be wrong, I dont see why they need the compacting machine for 4 days for the space you've described. And I've seen much cheaper renting prices ,  less than 10k.

You can do slight calculations for concrete volumes etc and you can know if you're getting hit big time by your contractor. Note that the figures may not be exact but they give you a rough idea.

@battleaxe and chaircover, thanx so much for your input.

@battleaxe, do you see the other figures also as excessive? pls comment. I guess I have to also have to leatn how to calculate these volumes myself. Thanx again

@chaircover,

I was also given low prices in the range of 18 to 23M on different occasions, even 15M! It is well. One has to take it little by little while being wise. God is in control.

[b]Poor you, your contractor is having a field day.
A raft foundation for your kind of work shouldnt cost more than 4 million including the filling. The fillings was way overbloated.
And what does hardcore really mean? Its just some crap invented by contractors to milk the uninitiated clients. There are some special types of fillings, usually mixing the red with the light-pink ones together give you a solid stone like result after been touched by water.

This is the estimate I currently shared with a client who wanted something similar:

Foundation Explanation:
layout, rough carpentry for raft, welding and iron casting, concrete casting, filling, German floor, raft extension, and foundational plumbing and electrical work layout work.

Materials:
2 tonnes of 16mm, Cement, 20 dozens of Rings & Binding wires, 200 pieces of 10x12, 100 pieces of 12x12, 3 trucks of Granite, 2 trucks of Sharp Sand, 50 trucks of Fillings at #20,000 per 1, Water: (Digging a well), Geepee tank, Transportation of materials.

The complete total for the foundation = #3,490,000

And not a single dime would be included. The guy just messed you up with several meaningless technicalities he included in the estimate. Usually, its the kind of english home owners love to listen to but in most cases its professional ojoro. Pardon my english.
I wont get involve in this, but you call me, I can help you straighten him and tell you how to deal with him or simply get someone else:[/b]

Heres what I posted once more. I sincerely hope whoever it is wont delete it.

Your contractor is having a field day.
A raft foundation for your kind of work shouldnt cost more than 4 million including the filling. The fillings was way overbloated.
And what does hardcore really mean? Its just some crap invented by contractors to milk the uninitiated clients. There are some special types of fillings, usually mixing the red with the light-pink ones together give you a solid stone like result after been touched by water.

This is the estimate I currently shared with a client who wanted something similar:

Foundation Explanation:
layout, rough carpentry for raft, welding and iron casting, concrete casting, filling, German floor, raft extension, and foundational plumbing and electrical work layout work.

Materials:
2 tonnes of 16mm, Cement, 20 dozens of Rings & Binding wires, 200 pieces of 10x12, 100 pieces of 12x12, 3 trucks of Granite, 2 trucks of Sharp Sand, 50 trucks of Fillings at #20,000 per 1, Water: (Digging a well), Geepee tank, Transportation of materials.

The complete total for the foundation = #3,490,000

And not a single dime would be included. The guy just messed you up with several meaningless technicalities he included in the estimate. Usually, its the kind of english home owners love to listen to but in most cases its professional ojoro. Pardon my english.
I wont get involve in this, but you call me, I can help you straighten him and tell you how to deal with him or simply get someone else:

Mr Larimo, you problem like most Nigerian clients, is refusing to employ appropriate professionals who would have saved you tons of money for a small fee.

You should have gotten an independent quantity surveyor to prepare a bill of quantities from the working drawings and structural drawings.

You should have called two or more contractors to bid for the contract based on the bill of quantities.

You should have had your architect supervise critical stages of the construction process, to make sure the design is being built according to design and material specifications.

If you have done these you would have had some checks and balances on your contractor and any increase in cost or material would be accounted for.

Now no use crying over spilt milk, so i would look at your complaints and add mu 2 cents, just for academic purpose.

larimo:

Fellow Nairalanders,

I need your technical input as regards my twin duplex under construction!  The calculated estimate was given as 18M-23M by a professional. I hv spent over 5M already on the foundation being adjudged to be water-logged, 100% above d estimate. I hv recently done the casting and the next stage is filling. I have been so turned off by the skyrocketting costs. The foundation is 5 boards in place of 3/4 boards with 10 tons of reinforcement! Does this change in foundation the previous estimates from the ground floor up to roofing?

See below a breakdown of future costs from the filling to roofing:  

65 trips of filling sand of 20 tons + labour @25,000/trip=, 1,625,000
Concrete work(granite,sharp sand,cement,e.t.c)=, 1,500,000
Reinforcement 5 tons, N650,000
Hardcore 2 trailers, N200,000
DPC membrane(nylonlike material for stopping water from going up), N40,000
Renting of compacting machine (4days),  N100,000
2 trips of sharp sand, N100,000

Soak away
Concrete for (2), N370,000
Reinforcements 2 tons, N260,000
Planks 120, 172,800
2 x3 & 2 x4, N22,500


GROUND & FIRST FLOOR
Blockwork to first floor, N1,814,400
First floor slab=1,500,000 +132,000, 1,632,000
Reinforcements 8 tons, N1,040,000
Columns concrete, N1,320,000
Reinforcements 3 tons for columns, N390,000
Lintels + Arc concrete, N184,800
Carpentary for lintels  132 planks +transport, 95,040
Carpentary for slab + beam 1005 planks, 723,600
Props (bamboo to carry first floor slab), 258,500
2 x 3 (240), 96,000
Labour for carpentary, N700,000
Nails + binding wire, N160,000

Blockwork to roof level same as g.f, N1,814,400

Roofing aluminium, 1,632,000
Carpentary for roof, 1,245,472

TOTAL=18,146,512!!!!!!! This means 23M+ already higher than estimated project cost!!

I am stunned, confused and speechless. Any encouragement and criticisms would be welcome. Thanks!!!

Like battle axe mentions your laterite looks way over exaggerated.

It is very difficult to comment on the concrete work without knowing the exact volume of concrete required and the concrete mix used by your contractor. You have so many confusing figures for concrete;

Concrete work(granite,sharp sand,cement,e.t.c)=, 1,500,000
First floor slab=1,500,000 +132,000, 1,632,000
Columns concrete, N1,320,000

Explain these figures, also the columns concrete looks way off.

The 1005 planks for the slab is obviously exaggerated for a 27 x 12 slab you would not require more than 450 planks. So also the bamboo it is exaggerated.


If you have spent over N18million for your "structural carcass" expect to spend a similar amount for your finishes and and landscaping.

I also want you to get in touch with me for advice with your finishes at wirinet @ yahoo.com

.

Ytechconst:

@Larimo

Please can you show us the architectural drawings and the structural drawings of the said twin duplex, if we know the quantities after taking off the drawings then we can judge what is going on may be you are being cheated or not, because i have seen cases of so many client who does not consider the cost of constructing a particular design during the design stage, all they are after is "i cherish this design and i want it" without remembering that structural members consumes concrete and reinforcements which are the most costly materials.

Could you give me your email addy?

paragonpro:

Mr Larimo, you problem like most Nigerian clients, is refusing to employ appropriate professionals who would have saved you tons of money for a small fee.

You should have gotten an independent quantity surveyor to prepare a bill of quantities from the working drawings and structural drawings.

You should have called two or more contractors to bid for the contract based on the bill of quantities.

You should have had your architect supervise critical stages of the construction process, to make sure the design is being built according to design and material specifications.

If you have done these you would have had some checks and balances on your contractor and any increase in cost or material would be accounted for.

Now no use crying over spilt milk, so i would look at your complaints and add mu 2 cents, just for academic purpose.

Like battle axe mentions your laterite looks way over exaggerated.

It is very difficult to comment on the concrete work without knowing the exact volume of concrete required and the concrete mix used by your contractor. You have so many confusing figures for concrete;

Concrete work(granite,sharp sand,cement,e.t.c)=, 1,500,000
First floor slab=1,500,000 +132,000, 1,632,000
Columns concrete, N1,320,000

Explain these figures, also the columns concrete looks way off.

The 1005 planks for the slab is obviously exaggerated for a 27 x 12 slab you would not require more than 450 planks. So also the bamboo it is exaggerated.


If you have spent over N18million for your "structural carcass" expect to spend a similar amount for your finishes and and landscaping.

I also want you to get in touch with me for advice with your finishes at wirinet @ yahoo.com

I did a BOQ and I have extensively sought a lot of 'professionals' for their input. The highest estimate I got was 28M. My architect is supervising this project along with a building engineer he brought. Though I have trusted him (d architect), these unimaginable costs have put me in a tense doubting mode. Its worrying for our real estate sector.

Concrete work(granite,sharp sand,cement,e.t.c)=, 1,500,000. this is for the german floor
First floor slab=1,500,000 +132,000, 1,632,000. first floor slab
Columns concrete, N1,320,000. columns (4 in number)

Thanks all for your criticisms and advice. More please!

@larimo

Again, a little calculation for the german floor.

Area = 27 X 12 = 324sqm
Not sure how thick your oversite bed will be but lets assume 200mm(8", though I have a feeling it may not be this thick. Just insert the thickness you're told here. (200mm = 0.2m)

Volume = 324 X 0.2m = 64.8cum (this is actual volume to be casted)
Add about 40% for wastage, shrinkage etc,
Volume = 64.8 X 1.4 = 91cum (this volume is useful for good estimation of materials)

Now, to your mixing ratio. I will use a 1:2:4 mix ratio here though I'm not sure what your structural engineer requested. I am also sure that if you're using the 3/4 inch granite, the sand quantity gets tweaked a bit upwards so might end up as 1:3:4 and this will mean less cement and granite. Also, unless the labourers are very wasteful, you rarely have up to 40% overages. Please ensure proper supervision during your casting to make sure the quoted mix is used. For thisc alculation though, I have also ignored all these variables and will assume a straight 1:2:4 mix.

Usiing a 1:2:4 ratio (cement:sand:granite)

Cement = 1/7 X91 = 13cum of cement
1 bag cement = 0.035cum. Bags needed = 371bags = 18.5tons of cement

Sand = 2/7 X 91 = 26cum
I tipper = 3.81cum. No of trips required = 7 trips of 5 ton sharp sand

Granite = 4/7 X 91 = 52cum
No of trips required = 14 trips of 5 tons granite

Cost :
Cement: 18.5 tons X 32000/ton = 592000
Sand: 7 trips X 10000/trip = 70000
Granite: 14 trips X 23000= 322000
Labour : I'm sure you should find a caster that will collect abt 150k or less(including mixer, vibrator) but lets use 200k.
Total = 592 + 70 + 322 +200 = 1,184,000

Please note that I have used the prorated rates for buying bigger tippers of materials. So instead of buying 7 individual trips of 5 ton sand, why not buy 20 ton trailers instead?

You decide if your contractor is cheating you. If you have figures, just play around and see what you come up with.

@battleaxe, God bless you for your insightful response . I have been enlightened.

@battleaxe, yemtechconst, aasog,

now the foundation has been changed from 3 boards to 5 board. Does this also change the previous estimates for the rest of the building, that is, the german floor, the blockwork, first floor slab, upwards, etc Should the rest of the structure change too? Is the fortification on the foundation not meant to keep the planned designs intact?

Your sincere thots please,

Input please!!!

any more bright ideas?!?!

@ battleaxe, and any other professional

your brake down and calculations just shed some light on how things work. If I may ask, are you in the Lagos area? I would like to get in touch with you as I am thinking of embarking on a similar project in Lekki-Ajah, Lagos. The difference between that of "larimo" is that instead of a twin duplex, mine is a 5 bedroom duplex and 2 flats-all connected (one flat at the top and one at the bottom) each flat has 3 bedrooms. I would like a quote for just the raft foundation. let me add that i would also appreciate in put from any other professional. Please let me have your estimated quote and contact.

Can sum1 pls giv me a quotation of a 4 bedroom twin duplex in ajah(dry land) from foundation to finishing.I will await your urgent reply

@DCGUY & tonjon. You can contact us @ abidoyventures@gmail.com or 08023142108.

@Battleaxe,yemtechconst and aasog contact me at jimtexx@yahoo.com. Thanks

Some contractors here are already quick to condemning the posters contractor without actually knowing the true nature of the project

.

battleaxe has done a good job, fried rice judgment sounds professional supported by ytechconst, but i will like to politely say disagree with assog projection, cos in my recent experience with raft foundation in lekki Ajah axis your figure will just be good for detached 5 bed rm detached duplex. Well that is not to say Larimo contractor is having a field day or not. But it is ideal to have a basis for judgement just like battle axe and others has ssuggested. It is advisable you have a bill of quantities either i format that you will be able to administer urself or the consultant will administer it for you. i can assure u you will save a lot at the end.