How to calculate numbers of blocks from a building plan.
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Most asked question from a would be house owner is always how many blocks do I need to get my building completed. Hence this topic is written with illustrations to make it easy for you to do
the calculations yourself from the plan your architect gave you.
The plan above is for a 2 bedroom bungallow, so we are going to start from the basics having in
mind these factors-
i)The lenght of a block is 0.45m or 450mm or 18″
ii)The width of thickness varies -150mm or 6″ and 225mm or 9″ which are most common.
ii)Taking for a general or average purpose, the blocks laid from foundation to dpc(german or
oversite concrete) is 4 coaches/levels. From dpc to the base of window another 4 coaches,from
base of window to top of window another 5 coaches, then from top of window to base of roof
another 3 coaches, neglecting the lintel or concrete on top of window.
Now with these parameters let calculate the plan above which has a wall of 150mm or 6″ all
through.
Add the length and breadth of the blockwall for external and internal
Therefore (A)9,400mm +9,600mm(B)+9400(C)+9600(D)=38,000mm or 38m
Now add the internal walls too
(Follow the grid lines and check the corresponding dimensions on plan remember 150mm is the
block width)
(Grid 7)150+3600+150+150+3600+150=7,800mm or 7.8m
(Grid 6)1350+150+2250+150+825+675+150=5,550mm or 5.55m
(Grid 1b)800+2400+1300+900+100=5,500mm or 5.5m
(Grid 2)2600+900+100+150+100+900+500+150=5,400mm or 5.4m
(Grid 3)1800+150+650+900+250+900+1450=6,100mm or 6.1m
(Grid 3b-Kitchen)900+50+1200+50+150=2,350 or 2.35m
(Grid 7b toilet)1800 or 1.8m
Total internal walls=34,500mm or 34.5m
Therefore Total walls=38,000mm +34,500mm=72,500mm or 72.5m
Now for the first 4 coaches to dpc level the wall will run right through, i.e the spaces for
doors or windows are not left out (n/b- blocks are used in relatively strong and stable soil not
waterlogged area that requires concrete instead).
Divide the sum by 450mm to know the numbers needed for one level/layer/coach of blocks
72,500/450=161 blocks
From dpc level to roof lets take the numbers of coaches to be 4+5+3=12 coaches
then multiply the numbers of blocks for each coach above by 12
161 x 12=1932 blocks
Don’t forget we have windows and doors spaces which we need to remove,for each window of 1200mm
take numbers of the block to be 14 (i.e 1200/230=5.2 and 1200/450=2.6 ,5.3 x2.6=14 approx
Now count the numbers of 1200mm windows and multiply by 14
Total numbers of 1200mm windows as counted on plan is 12 (note 2400mm window was taken as two of
1200mm window)
i.e 11 x 14 =154 blocks + 7 blocks for 600mm window for toilet. Total=161 blocks
Now calculate for doors,Numbers of blocks for a door of 900mm is 18.
height of a door(2100/225=9)+width of a door (900mm/450mm=2). so 9 x2 =18 blocks for each door.
Multiply 18 by numbers of doors=18 x8=144 blocks
Add 144+161=305 blocks,then remove from total blocks of 644 (for dpc) + 1932
Total numbers of blocks reqd=2,271 blocks
For a quick calculation, having the entire length to be 72,500mm. Take for a bungallow total
lenght from foundation to roof to be 1,200mm +3000mm=4200mm
Then calculate the surface area which is 72,500 x 4200 and convert to meters
72.5m x 4.2m=304.5m2
Remove surface areas of windows and doors
For window, height is 1.2m and total is 11
i.e 1.2m x 1.2m x 11=15.84m2 +0.6 x0.6(toilet window)=16.2m2
For doors, height is 2.1m while width is 0.9m
i.e 0.9 x 2.1 x 8(nos of doors)=15.12
Total area for doors and windows=16.2m2 +15.12m2=31.32m2
Remove 31.32m2 from 304.5m2=273.18m2
Now divide this by surface area of a block which is 0.225 x 0.45=0.10125
The blocks reqd caculated by this method is 273.18m2/0.10125=2,698 blocks
Note a difference of about 400 blocks from the two calculations. Of course you can’t get exactly
the numbers you need but the first method is close to it. And calculations are not 100% true
because of these factors
1-The mortar space was not considered
2-Blocks that will be wasted due to breakages e.t.c
Tags: 2 bedroom bungalow, blocks, bricks, calculate numbers of blocks, dpc, estimate
October 24th, 2010 at 3:21 pm
man you a doing a wonderfull job but dont take out of the table for we engineers, but you a good keep it up
October 30th, 2010 at 6:07 pm
a chartered QS will calculate the same way. thank you for a job well done
December 30th, 2010 at 7:49 pm
Your works has being providing great information that are accurate. Thanks and God bless
January 17th, 2011 at 10:16 am
I really like this. Thanks a lot.
January 17th, 2011 at 10:07 pm
Thank you.
January 19th, 2011 at 7:45 pm
what an emperical formaula. thank u
March 10th, 2011 at 9:36 am
How many 6inches block and 9inches block can i use to raise two flats each with 3 bedroom from german floor level?
May 11th, 2011 at 8:03 pm
thank u for revealing this method of calculations, now i know what to plan and budget for my building.
July 4th, 2011 at 4:05 pm
can u train a layman briclayer
July 5th, 2011 at 12:56 am
No I can’t but I have bricklayers such person can learn from.
Thanks
July 8th, 2011 at 12:42 pm
you dnt want the contractors to earn 4m thetr fruit.
July 18th, 2011 at 9:47 am
Thanks, I have applied it and worked 97%.
July 19th, 2011 at 12:47 pm
Is great having people like you in this our part of the world.
Keep the flag flying.
Thank you.
July 19th, 2011 at 5:51 pm
This is simply brilliant! I am amazed! Thank you
July 19th, 2011 at 10:10 pm
Thanks
July 19th, 2011 at 10:15 pm
This site is not to disenfranchise builders but is to encourage more Nigerians and Africa in general to build their own houses.
Thanks
July 27th, 2011 at 7:54 am
Knowledge is power and information a weapon when in the hands of the wise. Having the quality of information you are supplying on your site will definitely keep us ahead of fraudulent building contractors. But I dare to say that supervision can also go a long way in ensuring getting the right kind and quality of building services we require.
August 8th, 2011 at 6:29 pm
I prefer method 1 plus 10% to make up for differences and breakages. This would give us 2271*227=2498. Lets say 2500 blocks which is fair and much more realistic than method 2. I’ll write an excel prog to do this calculations for me for every plan. I will find a way to share when I do.
September 19th, 2011 at 2:13 pm
Man, you are doing a wonderful job. I wonder if there is any nigerian that can do this without asking for money. God will continue to bless you.
Please tell me, how many blocks can I use to put up a 4-bedroom flat.
Regds.
Martins
October 12th, 2011 at 8:27 am
Man, dis is a free Engineering course online, u ar gud, keep d gud wk up
October 15th, 2011 at 12:18 pm
I appreciate what you have done and want to be informed well be the actual name of the levels of blocks laid i.e ‘coaches’ or courses? As a teacher I will assume all you said to be true and I do not see the interchanging of the above words to be okay for fear of misinformation. Keep up with the good work
October 15th, 2011 at 12:19 pm
I appreciate what you have done and want to be informed well about the actual name of the levels of blocks laid i.e ‘coaches’ or courses? As a teacher I will assume all you said to be true and I do not see the interchanging of the above words to be okay for fear of misinformation. Keep up with the good work,
November 3rd, 2011 at 10:28 pm
I’m short of words, don’t know what to say to you, God Bless you for posting this but pls don’t remove anything from here as we engineers will always need it.
November 7th, 2011 at 9:34 am
U doing a gud job.
December 1st, 2011 at 9:46 am
THANKS FOR WELL DONE JOB.
December 17th, 2011 at 12:03 am
Thank you for your practical knowledge inculcate in me.
December 29th, 2011 at 5:03 pm
This is very good!u have real orientation about building.thanks, u ar a blessing
January 9th, 2012 at 5:03 am
I really enjoyed this online,thanks you ve really help me.
January 10th, 2012 at 3:09 pm
I credit you by all ur calculations and explanations. Even a novice will grab all your steps.you are really helpful to those outside there. Thanks for ur efforts.
January 31st, 2012 at 12:56 am
hello guyz am Dan,a quantity surveyor in making.i must confess dis is brilliant its my job buh ur doin it so perfectly i learnt new tins 4rm u.kip it up.
February 10th, 2012 at 11:17 am
An ideal builder dose’nt cheat. Please know that we calculate for un-avoidable waste thanks.
February 10th, 2012 at 11:19 am
An ideal builder dose’nt cheat. Please know that we calculate for un-avoidable waste thanks. N.B. You did a nice job here
February 16th, 2012 at 12:50 pm
y dnt u teach every Nigerian hw to design building too
February 16th, 2012 at 12:57 pm
my point is stop making it too simple,let it be more technical so that its the real professionals or construction students it wil appeal to and boring/confusing to those who don’t have any business there. Let them get the service of professional!
February 25th, 2012 at 9:29 am
Though, you’ve tried but want to remind building clients that they should avoid quack contractors, because they’ve no sound jobs to provide rather than waste products. For me I make sure I charge my various client what will due for my work expertise and render my best service to them. Honestly, all my client all over the globe love me and my artistic hand work. It is GOD’S doing. Cheers.
March 2nd, 2012 at 5:19 pm
Infact i am very greatfull keep it up, because as a Building Student u have to know this.
March 9th, 2012 at 5:35 pm
Truely you are good and i love you
March 18th, 2012 at 5:25 pm
Thanks man. But I think there is a little mistake in the first calculation that changed the result of second calculation. You added the dpc blocks twice. Because if the total girth is 72500mm/450=161blocks per coach, multiply by 12coaches=1932.then diduct the openings which is 305=1627blocks. Then add 5% waste.
March 22nd, 2012 at 6:31 pm
What a gr8 job well done, i am thrilled about this calculation, most esp. We in Building Technology, and also a Teacher of Brick, Blocklaying and concrete at GTC in Enugu, it has created a tremendious value to breake down my lession plan when it comes to calc. Of blocks, and i prefer mtd1. Kp d gud wrk.
March 24th, 2012 at 8:22 pm
pls i need answer to this question,how block should be lay into foundation before dpc.in your write up you put 4 coaches/levels but from my research i observe that 3 coaches of block is put into the foundation before dpc.pls any reaction to this
March 24th, 2012 at 11:02 pm
There is no standard on the numbers of block it depends on the design, topography or level of ground and what you can afford. You noticed this in your area because is highland.
March 24th, 2012 at 11:03 pm
Thanks.
March 30th, 2012 at 8:13 am
Thanks very much Emma, for what you have describe on how to calculate a number of blocks in a plan, most of time i use to ask my friend to do it for me but now i thank you i will start to calculate my self.
keep it up
i love it.
April 1st, 2012 at 10:41 pm
Tanks i love ur article God bles u o
April 1st, 2012 at 10:45 pm
Pls sir, i want u 2 explain 2 me how to convert metre cubic to tones. eg 3.8m3 to tones how ll i go abt it sir….
April 10th, 2012 at 1:08 pm
Tankz 4 dis wonderfull work i am really impressd 2 see dat we hav compitent engineers like u. Keep up d civil engr. Flag flaying.
April 15th, 2012 at 6:54 pm
Sir,I am in need of suitable plan drawing for a land of 30ft by 120ft such that the frontage or half of the land is needed to be used for a four bedroom flat while the remaining half is needed for mini flat of room and parlour,kitchen toilet and bath en suite.And the cost for the accomplishment of the project.
May 13th, 2012 at 10:40 pm
Weldone a very good submission you have and highly educating , the only observation though is the layer of block is “course” and not “coach” as you kept repeating believe it must be a typo .
May 19th, 2012 at 9:10 am
You save a society if not a world for this highlights. More than a job well done. Thank you so much man.
May 20th, 2012 at 7:17 pm
Its good for every 1 to learn d basics, howeva, I must caution here dat drwns r not always tis simple and a Civil Engr. must be consulted when d need arises.
June 7th, 2012 at 9:38 pm
Thats great of you. Its very helpfull to some of us who are practicing as quantity surveyors. Bravo
June 16th, 2012 at 10:32 am
Hi Emma,
I av bn receiving ur e-mails, thanks so much. I av a worry that your site posts are too simple, please be more tecnical, you are rather strenghtening the arm of quacks. There are professionals in the field, thanks.
July 14th, 2012 at 1:17 am
Thanks for this work.
July 23rd, 2012 at 1:23 pm
I must commend u, u did a nice job and calculations here, but u did not deduct the Lintels(concrete work) because they are not block work. If u do thatu will get the acurate number of blocks required. Thanks
July 30th, 2012 at 11:58 am
I really appreciate your calculations and don’t even bordered to pay attention to some people’s crazy comment you did this because you wanted many people success in life only GOD can pay you back all your effort of generocity,may GOD bless you,your family and your unborne generations thank you sooooo much.
August 2nd, 2012 at 5:23 pm
thanks 4 d good job
August 6th, 2012 at 9:08 pm
An excellent task, very simple and understandable
August 15th, 2012 at 7:07 pm
U did a very wonderful job. God will continue to guide u.s.
August 17th, 2012 at 2:45 am
sir,you are amazing pouring your beautiful mind out without a kobo.
God is watching you don`t worry
August 17th, 2012 at 12:15 pm
Thanks. An easier way is just to keep in mind that ‘for every 10 feet, 6 blocks are required. Hence cal the total length of the wall, multiply by 6 and divide by 10. Example for the length of 72500mm equals to 238feet. Now no of bloks =237*6/10 =143(each coache) now for 16 coache =143*16=2288. This has taken kia of d space for mortar. Just subtract the no of bloks for doors and windows. Hope this will be helpful
September 2nd, 2012 at 4:18 pm
nice job.i hv learnt alot.kip it up
September 9th, 2012 at 4:48 pm
If we have 1/10 of you kind of person then this world will be a better place, you are really “EMMANUEL”. May GOD bless you.
September 19th, 2012 at 8:03 am
I really appreciate dis wounderful informatns giving By U my Honorable Emma Do. Thanks keep it up.
October 8th, 2012 at 2:09 pm
My dear, I appreciate your good wood. Your information is helping lay men to have rudimentary knowledge about building so that they will not be cheated out completely. God bless you mightily.
October 15th, 2012 at 10:13 am
it helps a lot to have people like you thank you very much.
October 31st, 2012 at 1:42 pm
I pray God 4 his gr8t wisdom on u. Pls forward dis page 2 my e-mail box. Tnks
October 31st, 2012 at 9:36 pm
your enlightment on this simple small building plan would definately encouraged sincere and honest building contractors.
November 8th, 2012 at 9:43 am
gud job! u did well keep it up an God will improve u an ur tarlent
November 29th, 2012 at 2:03 pm
Man you are doing a great job here, never look or mind your critics they are cowards, keep it up.
December 8th, 2012 at 10:45 am
good job….well done
December 13th, 2012 at 1:22 pm
i need a q.s to train me so that i can become an expert on estimating, kindly hook me up with one.
December 13th, 2012 at 1:24 pm
wel done
December 15th, 2012 at 6:13 pm
U’v done a gud job of educating us.bt wat is dpc and oversite concrete,how can one achieve d foundations 2 oversite concrete,is hard core important.
December 15th, 2012 at 10:48 pm
thanks this is a study material, God bless u.
December 16th, 2012 at 3:53 am
D great Qty-Syr, dats what you are. Keep it up
December 20th, 2012 at 2:23 pm
Quite encouraging. I am glad i looked this up, really educative, God would widen your knowledge more.Thank you
December 22nd, 2012 at 9:32 am
Its nice. Am a Qs undergraduate. I love what u are doing. God bless u. Pls enlighten us on celin and noggings
December 26th, 2012 at 3:49 am
I must confess you are my God sent, have been battled with this for a year. This is a good job.you are the first person to give analysis or details of what have been willing to know thanKs so much you are the best by God grace.
December 26th, 2012 at 3:53 am
Thanks Sadiq, I am happy you find the information useful.
December 26th, 2012 at 3:54 am
@Ife you can call this man Q.S Olayode-08023127251
January 26th, 2013 at 8:42 pm
Well, am really fulfilled for this calculations .this would help me out for all my proposed plan of putting up some structures.
February 10th, 2013 at 9:40 am
Well done and may God reward u aboundantly
March 6th, 2013 at 1:42 am
This gives me great encouragement to build. Never mind Nigerians who are overwhelmed by the cheating culture will not like this but keep it up. God will amazingly reward you and many genuine people will come paying you for this services you give out free. Imagine how many building students appreciate this. Keep it up.
March 7th, 2013 at 7:50 pm
Very educative for prospective house owners. Thanks
March 31st, 2013 at 10:05 am
You have done a great job keep it up
April 2nd, 2013 at 5:54 am
What a good job you have done here, but please let me know how many blocks will be needed for a 3-bedroom flat
April 7th, 2013 at 12:58 am
Realy amazing explainations here. As a building student,I must confess that it help me in my exams work and still is. ChEers!
April 8th, 2013 at 7:57 am
i really loved this, thank u.
May 8th, 2013 at 8:05 pm
I wld want 2knw if u entertain calls c0s I’ve sent a number 0f unreplied messages 2u b0rdering 0n hw I culd be abs0rb in ur firm as an Intern 0r link 2 an0ther pr0fessi0nal, still an Undergraduate 0f Building wt d zeal 0f acquiring kn0wledge!