Materials
Phases of a Construction Project
Building construction involves a significant investment and a process that can take months or even years. During this time, various stages of the construction project unfold, their duration and success depending on the contractor’s management, the construction system employed, and the established timelines.
To understand the phases of a construction project, it is necessary to delve into each one in detail to unravel its complexity and grasp the associated risks. This approach allows us to evaluate the best execution option for a project, considering safety, cost control, and construction deadlines.
PHASES PRIOR TO BUILDING CONSTRUCTION
Before reaching the construction phase, we go through different stages that allow us to obtain a detailed architectural project, approved by the College of Architects, and with a building permit suitable for commencing construction.
PHASES OF AN ARCHITECTURAL PROJECT
The construction of a building constitutes one of the fundamental stages in an architectural project. It all begins with evaluating the project’s viability, moving through the definition of the complete project, to finally applying for a building permit and ultimately carrying out the execution of the building’s construction.
Let’s examine each of them in detail:
Project Feasibility Study
When undertaking a construction project, as with any other project, a preliminary study is necessary to evaluate the total investment and its amortization. This analysis is especially common in office building projects or residential developments. In the case of single-family home construction, viability can be assessed by comparing it with the acquisition of a second-hand home or by calculating mortgage amortization in relation to monthly rental investment.
Preliminary Project
The preliminary project is the essential starting point for construction development. It constitutes a creative phase where the environment is studied, and initial proposals are put forward through plans and models, which may be modified in later stages of the project.
The Basic Project
The basic project delves deeper than the preliminary project, defining the general characteristics of the work with greater precision by justifying specific solutions. This allows for a general conception of the building and the acquisition of the building permit.
The Executive Project
The executive project goes into greater detail and includes all the necessary documentation for the project’s construction. It is a detailed description covering all aspects of the building development: foundations, structure, and installations, all calculated and designed in compliance with current regulations, making precision crucial.
Endorsement and Building Permit Management
To initiate the building permit application process, both the basic project and the executive project must obtain the endorsement certificate from the College of Architects. Once the building permit is obtained, site management and its respective monitoring proceed to ensure correct execution.
Site Management
In this stage, the project is built in phases following the documentation presented. The role of the site manager will be necessary, who usually coincides with the architect responsible for the project’s design.
Site management, also known as facultative management, is the team of professionals responsible for supervising and ensuring the correct execution of the work. In Spain, according to the Building Planning Law (Ley de Ordenación de la Edificación), facultative management comprises the site manager (DO), the construction execution manager (DEO), and the health and safety coordinator (CSS).
The role of site manager can be performed by an architect or a technical architect, depending on who drafted the project. Both the site manager and the construction execution manager are responsible for ensuring proper project execution. However, their roles differ in their approaches: the site manager handles aesthetic, technical, urban planning, and environmental development, while the execution manager focuses on quality and quantity control. Thus, the DEO reviews the executive project, from foundations to finishes, and together with the architect, carries out the necessary setting-out in each phase of the work.
The Building Planning Law (LOE) includes specific rules that determine the responsibilities of these professionals. Accordingly, the risks that each agent assumes based on their activity are determined, as damages to the building or to third parties may arise during the construction process and must be covered by insurance.
Among the available insurances, the all-risk construction insurance stands out, covering all material damages to the building caused by accidental and unforeseen events. Likewise, it is important to have ten-year liability insurance, advance payment guarantee insurance, and civil liability insurance. [1]
AGENTS INVOLVED IN THE BUILDING CONSTRUCTION PHASE
Throughout the design process, several agents are involved in addition to the architect, due to the great complexity it entails. First, the developer is the one who commissions the project and provides all preliminary information to the architect, who will be primarily responsible for designing a building suitable for the client’s needs.
Subsequently, in the executive project stage, the role of the technical architect becomes relevant, as they will direct the ongoing construction work. Likewise, other specialized professionals participate, such as energy efficiency engineers, installation engineers, structural engineers, geologists, and surveyors, each contributing their expertise in the different phases of construction. Similarly, the construction company plays a fundamental role in undertaking the building’s construction.
In large-scale projects, it is vital to have a Project Manager, an individual who directs, coordinates, and manages the project from start to finish, ensuring efficient and orderly execution.
To carry out this process, it is essential to comply with the regulatory framework established by the Building Planning Law (LOE), which defines the basic requirements for building related to functionality, accessibility, safety, and habitability of buildings. [2] These requirements are developed in depth in the Technical Building Code (CTE). In addition to complying with these regulations, it is essential to obtain the endorsement from the College of Architects to carry out the project. [3]
PHASES OF THE CONSTRUCTION PROCESS
The construction process is divided into ten phases that are generally followed in any construction, although they may vary in complexity depending on the type of building or situation, and are as follows:
Phase 1. Site Preparation.
Phase 2. Earthworks.
Phase 3. Foundations and Earth Retention.
Phase 4. Structure.
Phase 5. Enclosures and Carpentry.
Phase 6. Insulation.
Phase 7. Installations.
Phase 8. Finishes.
Phase 9. Exterior Spaces.
During each of these phases, work proceeds according to the documentation provided in the executive project and in accordance with the criteria, systems, and materials specified therein.
PHASE 1. SITE PREPARATION
Before constructing a building, it must be verified that the land in question is suitable and possesses the necessary properties for its occupation. This requires carrying out various preliminary studies conducted by geologists and surveyors.
The terrain has a significant impact on the building, as there are different types of soil, such as rocky, granular, cohesive, and deficient soils, which influence the foundation and structure of the project. It is essential that the project design adapts and conforms to the type of soil to ensure its proper functioning and durability.
SOIL TYPES ACCORDING TO THEIR RESISTANCE
Rocky soils are characterized by high resistance and low deformation. According to current CTE regulations, they must be explored to a depth of 2m + 0.3m multiplied by the number of floors to be founded, as they may present discontinuities, fissures, or other irregularities detrimental to the building.
On the other hand, soils differ from rocks in that they are composed of particles that can disaggregate. There are two main types: granular soils, composed of sands and gravels, and cohesive soils, composed of silts and clays. They differ in the size of their constituent particles, being larger in granular soils than in cohesive ones. This means granular soils have higher density and less compressibility, leading to rapid settlements. Cohesive soils, conversely, exhibit greater plasticity, resulting in slower settlements.
In any of the three cases, the soil can be founded and, therefore, be suitable for building. However, this is not the case when the soil is deficient, as its name implies. Deficient soils, including organic soils, natural or artificial fills, and inorganic muds, do not meet the necessary requirements for building.
GEOTECHNICAL AND TOPOGRAPHICAL STUDY
To determine the type of terrain and optimize construction, two fundamental studies are carried out: geotechnical and topographical.
The geotechnical study collects quantified information on the characteristics of the terrain, allowing for its recognition and classification. This information, along with data provided by the architect about the building, allows for a more appropriate resizing or replanning of the projected foundations and retaining walls. [5]
For this purpose, a reconnaissance campaign is carried out at various points on the plot, varying the depth according to the planned foundation in the project. Field tests are conducted, and samples are extracted for subsequent laboratory testing.
On the other hand, the topographical study precisely defines certain terrain characteristics such as elevation and levels through plans and graphic representations of the land. This topographical survey is accompanied by measurements of distances, elevations, or directions that allow the project to be located and construction errors to be avoided.
The information gathered through the geotechnical study and topographical profiles provides the necessary terrain values to adapt the project to the site and includes a report on recommended foundations. It also offers other complementary construction recommendations and work indications.
Both studies are carried out before the start of the technical project, but it is necessary to have them available when starting the work to share and evaluate the best execution solution. The steps followed in this first phase are the clearing of the area where the construction will be located and the leveling of the ground.
CLEARING AND BRUSH REMOVAL
Site clearing aims to remove any undesirable material or elements from the designated work area.
To do this, first, any debris or remnants of previous constructions, as well as the vegetation layer formed by weeds or shrubs, must be removed. In some cases, tree felling and root extraction will even be necessary. However, whenever possible, it is preferable to select trees that can be saved or relocated on the site.
Currently, there is a growing trend towards projects that respect the natural environment, opting for constructions that rest on few points, preserving existing trees or replanting them in different locations. Regenerative architecture, integrated into the landscape, seeks to minimize impact on the land and the natural environment, demonstrating a commitment to biosphere preservation.
LEVELING
Establishing the construction level is a crucial task that must be performed at the beginning of the project to set the ground floor level. To avoid potential flooding problems on the ground floor or the appearance of dampness in the walls, the marked level must be above the ground level. Additionally, if the plot is adjacent to the street, the ground floor level must also be situated above the sidewalk level.
From the ground floor level, which is taken as elevation 0.00, the other construction levels will be determined, and a setting-out approved by the Site Management will be carried out. This step is essential to ensure the correct execution of the project and prevent future problems related to the building’s elevation relative to the surrounding terrain.
PHASE 2. EARTHWORKS
This phase covers all activities related to earth movement, including excavations and backfills, material loading, transport, unloading, distribution, and compaction of earth. In small-scale projects, excavation can be done manually with shovels, which implies a lower environmental impact by avoiding the use of heavy machinery.
However, in most cases, due to the magnitude and complexity of projects, heavy machinery such as backhoes, hydraulic excavators, tractors, front loaders, rollers, or motor graders is used.
The characteristics of the excavation depend on the type of project, the terrain, and the planned foundations. The preliminary geotechnical study allows for estimating the magnitude and complexity of the excavation by providing information about the terrain.
There are two main types of excavations: for leveling and for foundations. Leveling excavations aim to standardize and level the starting ground for the building and include earth movements such as cut, excavation, and embankment.
– Cut: movement of earth located above the starting grade of the building.
– Excavation: removal of earth when the starting grade is below ground level.
– Embankment: filling of earth to bring the ground below the starting grade of the building to the same level.
Soil moisture can affect excavation. Depending on the presence of water, excavations can be classified as: dry when the soil has no moisture, saturated material when the soil has been directly exposed to water, and presence of water when the water table affects the excavation. If the excavation reaches the water table, it is necessary to pump the water out of the excavation.
On the other hand, this phase can generate a lot of waste and a significant impact due to earth movement. However, it is possible to reuse the excavated earth on the same site to minimize waste.
– Foundation Excavations
Foundation excavations are carried out using trenches, which are linear excavations where the foundation will later be placed. To perform these excavations, the earth is loosened and extracted following the marked guides that define the shape and dimensions of the trench needed for the planned foundation. These two steps are repeated until firm ground is reached, which will prevent unwanted settlements.
It is crucial that the bottom of the excavation is clean and level to ensure a solid base for the foundation. For this purpose, a lean concrete or fill is immediately poured after excavation, with a thickness of at least 10 cm. This helps maintain adequate ground conditions and provides a suitable base for the building’s foundation. [5]