Construction Cost Estimating

      

How Much Does It Cost to Build a 10?x10? Room?

Estimating the cost of construction is a big matter and everyone must do it before starting any project. With construction companies there are dedicated cost estimators to do it, but what if you are just looking to know how much does it cost to build a 10?x10? room? There you have to do it yourself and guess the entire building cost based on that. We can help here.

You would need to know an approximate cost of construction for quite a few good reasons. These include knowing the total cost of the construction, to understand the impact on budget, to figure out your maximum or minimum budget, to understand loan requirements, to compare quotes from contractors and to realize how much they are off from the actual rates.

Room Measurements: To know the costs to build a particular room, you have to figure out the exact dimensions of the room and also the dimensions of the objects within the room. For a typical 10?x10? room, the dimensions are as follows:

Room length: 10 feet
Room width: 10 feet
Wall thickness: 9 inches
Room outer length and width: 11 feet 6 inches
Columns: 4
Column dimensions: 9? by 9?
Beam dimensions: 9? by 12?

Armed with this data, let us go and see how much would it cost to build this room from ground up.

Calculations: To know the total cost, we will have to figure out the following five aspects. We will have to figure out their quantities and their respective costs.

1. Brick work
2. Concrete work
3. Reinforcements
4. Flooring
5. Labor

Now let us estimate each aspect of building one by one.

A. Brick Work: The brick work of a building consists of a number of bricks needed to construct the walls, and the mortar work that holds the bricks together. Mortar will be quantified in terms of cement and sand required. Brick work can be full-brick (9?, outer walls) or half-brick (4.5?, inner walls) - we have taken full-brick work in this model. We will also consider a parapet wall above the room.

Brickwork in room
Here, Length of wall
= 10 ft (3.05 m), (10 ft / 3.28)
= 3.05 m

Similarly, Width of wall
= 9 inch (0.23 m), (9/0.0254)
= 0.23 m

There are 4 walls having same length 10 ft.

Therefore, quantity of Brick work in room = 7.65 m3

Brick Work in Parapet: There are two wall having different length, so we name them as short wall and long wall.

Short wall length
= 11' 6? (11(6/12) / 3.28)
= 3.50 m

Long wall length
= 13' (13' / 3.28)
= 3.96 m.

Height of parapet is same for both
= 3' (3 ft / 3.28)
= 0.90 m.

Parapet wall Estimate - Total Brick Work

= Brick work in superstructure + Brick work in parapet wall
= 7.65 m3 + 0.71 m3
= 8.99 m3

Deduction of Doors and Window Quantity: The door and window space volume will need to be subtracted from the total brickwork volume when we are calculating the net brick work volume for the superstructure. This goes as follows.

Deduction for door (3?x7?): 0.43 m3
Deduction for window (4?x4?): 0.33 m3

So, net brickwork volume
= Total brickwork - (deduction for door + deduction for window)
= 8.99 - (0.43 + 0.33)
= 8.23 m3

Brick and mortar work estimate: Here we will figure out the cost of the bricks, and the amount of cement and sand required for mortaring.

1 m3 = 500 no.
Cement Sand ratio = 1:3
Cement = 2.15 bags
Sand = 0.225 m3
Brick: For 8.23 m3: 500 x 8.23 = 4114.16 Nos.

Cost of Brick (5 Rs/Brick) = 4114.2 x 5 = 20,571 Rs. Cement: For 8.23 m3: 2.15 x 8.23 x 17.69 Bags Cost of cement (Rs. 300/ Bags) = 17.69 x 300 = 5,307 Rs. Sand: For 8.23 m3: 0.225 x 8.23 = 1.85 m3 Cost of sand (Rs. 1250/m3): 1.85 x 1250 = 2,314 Rs.

Total Cost of brickwork = 28,192 Rs.

B. Concrete work: Here, we will first find out the total quantity used in all the beams, columns and slabs in the 10?x10? room.

Column Size = 9? x 9? (0.23 m x 0.23 m)
Beam Size = 9? x 12? (0.23 m x 0.30 m)
Slab Length
= 11?6? (11(6/12) / 3.28)
= 3.50 m

Width
= 13' (13/3.28)
= 3.86 m

4 pcs RCC Column = 0.65 m3
4 pcs RCC beam = 0.84 m3
1 pc RCC slab (10?x13?) = 1.39 m3
So, total RCC volume: column + beam + slab
= 0.65 + 0.84 + 1.39
= 2.87 m3

Total concrete work cost @3500/m3 = Rs. 10,045

C. Steel reinforcement cost: The steel amount in concrete columns and beams are generally 1-2% of the volume of concrete used in the concrete work.

Volume of Reinforcement (Steel) = 1% of Volume of Concrete
Volume of Steel
= 0.01 x 2.87
= 0.029 m3

We know the density of steel = 7850 kg / m3
From density and volume of steel, we can calculate weight of steel in kilograms.
Weight of steel
= 0.029 m3 x 7850 kg/m3
= 225.54 kg

Normal rate of construction steel is about 45 to 60 Rs. per Kg in market.
So, if we take 50 Rs. / kg rate, then
Cost of Steel = Weight of Steel x Rate of Steel
= 225.54 x 50
= Rs. 11,277

D. Flooring cost: Let?s say we are making the floor of standard vitrified tiles @25 Rs. Per square feet.

Area of room floor
= 10?x10?
= 100 sq.ft.

Therefore, tile flooring cost = floor area x tile rate
= 100 x 25
= Rs. 2500

E. Labor Charges: In the market, there are many variants of labor charges. Depending upon the nature of the building, the costs can vary from Rs. 170/sq.ft. To Rs. 500/sq.ft. - Let?s say we have taken @200/sq.ft. Labors.

Total Construction area in this room
= 11?6? x 11?6? (11.5 ft x 11.5 ft)
= 132.25 sq. ft.

Cost of Labor
= 132.25 x 200
= Rs. 26,450

Total construction costs of 10?x10? room - The segmented costs of the construction:

Brick work = Rs. 28,192
Concrete work = Rs. 10,045
Reinforcements = Rs. 11,277
Flooring = Rs. 2,500
Labor = Rs. 26,450

Therefore, the total cost of constructing a 10?x10? room is the sum of the above = Rs. 78,465.

How Much Does It Cost to Build a 10?x10? Room

Image Courtesy and Article Source: civiconcepts.com