When preparing to build a house that all homeowners and investors are concerned about is the cost of construction. The article “How to calculate the price of house construction” will divide the calculation of the cost of construction of houses into two specific steps: Calculating the value of construction and Calculating detailed estimates.
Calculate and estimate construction value
The calculation of construction value is based on statistics and experience of construction contractors. After a lot of works and a detailed final review, the experienced contractor will find statistical functions that correlate the cost and a certain variable. The most common and most common is the correlation between the construction area and the price per unit area. For example, we often hear that the current price of housing construction is … (eg VND 5.0 million / m2).
As mentioned above, the calculation based on unit price / m2 is based on statistics, so there will certainly be many errors and the reliability depends greatly on the number and quality of statistical samples. Specifically, the contractor must have many works on shape, quality of structural, geological, and similar stratigraphy to get a reliable statistical result. This is difficult in the present conditions, because when the Construction Association, the Association of Architects are unable to collect and analyze this data, it is very difficult for single contractors to have reliable data. Typically, the deviation of the estimated value calculated on the current unit price / m2 is quite high, may be more than 3% and in some cases up to 7%.
In consultation with the current construction contractors in Ho Chi Minh City, Binh Duong and neighboring provinces, the unit price of raw construction / m2 is calculated on average from 4.8 to 5.2 million dong per m2 building area (note not including fence, garden and interior). This construction area is understood as the area of the ground floor, the floors including the balcony. If the house is roof tile, the construction contractors usually add 30% – 50% of the unit price for the roof, which means adding from 1,440,000 – 1,560,000 VND for one m2 of roof tile. In addition, if building a foundation, the foundation will count 50% of the total floor area.
You need to learn about how to calculate the cost of building a house
For example: Building a house with a ground floor area of 100m2, building a 3-storey house and tile roof, the construction value is calculated as follows:
· 100 x 3 x 5,000,000 (3 floors: ground floor, first floor, 2nd floor) = 1,500,000,000 VND
· 100 x 5,000,000 x 1/3 (Tile roof) = 150,000,000 VND
· 100 x 5,000,000 x 1/2 (Foundation) = 250,000,000 VND
· Estimated total unit price: 1,500,000.00 + 150,000,000 + 250,000,0000 = 1,900,000,000 VND
Note: The above unit price is only applied for construction works with good geological structure, weak geological structure areas, the construction unit price must increase, specifically increasing from 10% – 15% of the price. Construction treatment for foundation reinforcement. According to the above example, if a 100m2 house was built in Nha Be, the estimated value would be VND 2,090,000,000 (ie an increase of VND 190,000,000).
Calculate detailed estimates
This is the most accurate method to calculate the cost of construction. In order to prepare an estimate for the house to be built, it is prerequisite that the expected construction work must be completed in complete detailed design documents, including geological survey records, architectural design records. architecture, structural design records, design documents of water supply and drainage systems, design records of electrical systems, phones, computers, security cameras, etc.
Based on these design drawings, the estimates will calculate the detailed estimate of the construction work. The calculation results of the estimates will give us three important calculation tables:
Estimated estimates:
In this table is the exact volume of all works and items to be performed from the start of the construction to the completion of the project. For example: How many m2 of brick wall thickness of 100cm must be built in the building, how many concrete blocks of floors, columns …
Summary of material expenditure:
This table lists the exact quantity and market price of all types of supplies to be used. For example: How many tons of cement, steel, how many bricks, card bricks and how much are they used to pay …
Summary of cost estimates:
In this table, the cost estimates will specify the costs of materials, labor and other costs when constructing the work. This is the final estimation result with high accuracy, the error is less than 1% for the valuation of a project.
Thus, depending on the importance of the work, depending on the level of accepting risks and errors, investors can choose a plan with high errors but quickly, simply (method of calculation (estimation) or choose a method for determining reliability (detailed estimation).