Factors contemplated during price applications
Several factors, that directly or indirectly influence the final cost of the work, are taken into account to obtain the prices used to elaborate the budget. These can be grouped into the following categories:
Geographic factors
These are factors related to the geographical and climatic situation of the area, which are intrinsically linked to the socioeconomic factors that affect the prices and performance of the workforce. These include:
- The population density
Affects the supply and demand, and therefore, the market price.
- The tourist development of the zone
Increases the demand and purchasing power of the inhabitants of the zone.
- The state and development of the transport networks
Affects the distribution and transport cost of materials, goods and services.
Socioeconomic factors
These factors depend on the economic, political and social situation of each zone, which influence the price of the materials, labour and machinery prices. These include:
- The net monthly salary in the construction sector
Influences the price of labour.
- The minimum interprofessional salary
Influences the price of labour.
- The gross national income per capita with purchasing power parity
Influences prices in general.
- The inflation rate
Implies a continuous price increase.
- The unemployment rate
Reflects the labour availability, and therefore, the contracting price.
- The currency exchange rate
Especially affects the import of goods and services.
- The market conditions
Provides an indication of the supply and demand relationship in the acquisition of materials, hiring of labour and rental of equipment and machinery involved in the construction process. No reference is made to the supply or demand of the real estate market, only to the demand by the contractor and the supply of materials, as well as to the labour market.
- The import of goods and services
Influences imported material prices.
- The industrial production growth rate
Reflects the availability of auxiliary measures to aid in the execution of the work.
- The corruption perception index
Affects prices in general, the greater the corruption index, the greater the cost of the work.
- The human development index HDI
Is an indicator of the health, education and economic level, which reflects the degree of competitiveness and productivity of the inhabitants of the area, and so, directly affects the performance and final cost of the building.
The adjustment coefficients associated with each socioeconomic and geographical factor have been quantified through the study and analysis of data provided by statistical sources of recognized authority, such as: World Bank, Datos Macro Expansión, IndexMundi, Preciosmundi, XE Live Exchange Rates, European Commission.
Typological factors
- The built surface
Affect the prices and labour performance
- The use of the building
Implies specific construction solutions and installations, and therefore, affects the final cost of the building.
- The number of floors above ground level
Increased height of the building implies more burdensome structural and construction solutions, as well as increasing difficulty to displace elements vertically, which implies a loss of performance.
- The number of floors below ground level
Building a basement implies an added difficulty, which affects the execution cost of the project, especially the land movement and foundation chapters.
- Average free height between floors
Directly affects the construction volume, especially chapters concerning façades, partitions and cladding, and with increased height, increases the difficulty to displace elements vertically.
- The type of building
Affects the configuration of the floor and façades of the building, and therefore, its construction.
- The geometric complexity of the floor
Affects the cost of the building, as it implies a general performance loss.
- Percentage façade openings
Openings in the façade imply an increase in its cost.
- The degree of floor partitioning
Affects the cost of the partitions, carpentry and indoor cladding.
- Its accessibility
The accessibility to the worksite is considered as well as the storage options.
- The topography of the site
The difficulties that are brought about due to the presence of uneven ground in the worksite, which affects the performance of machinery and labour, are quantified.
- Level of quality
It is intrinsically linked to the amount of the work execution budget. In the program, the level of quality for the whole building, constructive solutions and installations can be selected indistinctly.
The level of qualityis defined according to the characteristics of the materials, equipment and construction processes used in the project, according to the following criteria:
- Basic
Strictly comply with the standards in force. Their cost lies below the 30% percentile of the set of market prices.
- Medium
They exceed the minimum requirements that are prescribed by current standards and provide increased quality to the whole building. Its cost lies within the range defined by the 30-70% percentiles of the set of market prices.
- High
They exceed the minimum requirements of the current standards and provide a significant quality bonus to the whole building. Its cost is above the 70% percentile of the set of market prices.
Construction factors
Depending on the selected use of the building, the program defines the project units that make up the chapters of the budget:
- Land conditioning
- Foundations
- Structure
- Façades
- Roof
- Partitions
- Installations
- Cladding
- Signs and equipment
- Environmental management, control, health and safety
Users can change the default options that the program offers for each use.
Climatic and seismic factors
The program also contemplates these other factors that affect the cost of the building:
- Thermal conditions
The outdoor temperature affects the design of the envelope and thermal installations of the building, particularly, regarding the cost of the insulation and exterior carpentry.
- Wind intensity
The dynamic pressure of the wind conditions the design and cost of the structure, and the exterior carpentry.
- Wind exposure degree
It has an impact on the cost of the structure and exterior carpentry, especially in buildings located near cliffs, seaside, unimpeded rural land, amongst others.
- Seismic risk
Seismic actions affect the design of the foundations and structure, therefore, the final cost of the building.
Details
- Program download, available languages...
- User license
The permits that must be included in the user license to be able to use Open BIM Cost Estimator depend on the value of the execution cost that is calculated by the program:
- Up to 1,000,000 €
Users can use the program for free.
- Up to 5,000,000 €
The user license must include the Open BIM Cost Estimator Pro permit.
- More that 5,000,000 €
The user license must include the Open BIM Cost Estimator Expert permit.
More information
More information on Open BIM Cost Estimator can be found by clicking on the following links: