Project phase: why you shouldn’t start building a house based solely on a pretty visualisation

Once a plot has been chosen, one of the key stages is project preparation. It is the project that transforms the idea of a future home into a clear technical plan: what we are building, how we are building it, what materials we are using, in what order, and within what budget.

Attractive renderings help you visualise your future home, but they are not enough for the construction process. You need drawings, structural solutions, engineering sections, specifications and an understanding of how the project will be implemented on the actual plot.

1. A design is not just about architecture

Many people think of a design as simply the floor plan, façades and visualisations. In practice, a design must answer not only the question ‘what will the house look like?’, but also ‘how should it be built?’.

Key building regulations in Spain.

It is important to check:

1. Whether the design is suitable for the plot.
2. Whether it takes into account the topography and orientation of the house.
3. Whether the dimensions, levels and elevations are clear.
4. Whether the load-bearing elements have been properly considered.
5. Is the layout of the building services logical?
6. Can a precise cost estimate be calculated from the design?
7. Are there any solutions that look attractive but are difficult or expensive to implement?

A point that is not immediately obvious: the fewer technical details in the design, the more decisions will have to be made on site. And this almost always affects the timeline and budget.

2. The design must comply with regulations

In Spain, a design must take into account not only the client’s wishes but also the applicable building regulations. One of the key documents is the Código Técnico de la Edificación, which sets out the basic requirements for safety, habitability, energy efficiency, noise protection and other building parameters.

Legislation and regulations governing construction processes.

This is important not merely as a formality, but in practical terms. The regulations affect:

1. The structure of the house.
2. Energy efficiency.
3. Ventilation.
4. Thermal insulation.
5. Acoustics.
6. Safety of use.
7. Fire safety requirements.
8. Engineering solutions.

If these issues are not properly considered at the design stage, this may lead to alterations, delays or additional costs later on.

3. The architectural concept must be aligned with the cost estimate

One common mistake is to create an attractive design first, only to discover later that its implementation exceeds the budget.

A useful section for procedures relating to the Colegio de Arquitectos de Málaga.

At the design stage, it is important to understand straight away:

1. What materials are envisaged.
2. How complex the structure is.
3. Whether there are any non-standard elements.
4. How much the foundations will cost.
5. How much the windows, façades, terraces and swimming pool will cost.
6. What engineering systems are included.
7. Whether there are solutions that can be simplified without compromising on quality.

One point that is not immediately obvious: two houses of the same floor area can vary significantly in cost. The budget is influenced not only by the number of square metres, but also by the shape of the building, changes in level, large spans, panoramic glazing, retaining walls, the type of roof and the building services.

4. The structural design must be clear before work begins

The design must address questions regarding the building’s structure in advance: foundations, columns, walls, floor slabs, staircases, reinforcement, concrete and loads.

Before construction begins, it is important to understand:

1. What type of foundation has been chosen and why.
2. How the structure relates to the ground and the terrain.
3. Where the load-bearing elements are located.
4. Which areas require special attention.
5. Whether there are any complex joints.
6. How the services will be routed.
7. Whether the architecture and structural design conflict with one another.

A point that is not immediately obvious: if structural solutions have not been thoroughly thought through, problems often only become apparent on site – when machinery, workers and materials are already in place.

5. Engineering must be planned in advance

Engineering systems must not be left ‘until later’. Electrical systems, water supply, drainage, ventilation, air conditioning, heating, solar panels and smart home systems – all of these must be integrated with the architecture and structural design.

It is important to check:

1. Where the main service runs are located.
2. Where the service rooms will be.
3. Whether there is sufficient space for equipment.
4. How drainage will be organised.
5. Where the air conditioning units and ventilation will be located.
6. Whether the engineering systems interfere with load-bearing elements.
7. Whether there is access for maintenance.

A point that is not immediately obvious: if the services are not planned in advance, you will later have to cut into walls, relocate systems, alter ceiling heights or find compromises during the construction process.

6. The project is required for permits and approvals

When undertaking construction work, it is important to understand exactly which set of documents is required for submission and approval. Depending on the type of work and the local authority, a licence, a ‘declaración responsable’ or another approval procedure may be required. For example, the Málaga City Council has separate procedures for town planning and building works.

The Ley de Ordenación de la Edificación also plays an important role in Spain, as it defines the parties involved in the construction process and their responsibilities. For the construction of residential buildings, the design phase usually involves the work of a qualified architect and technical specialists.

Municipal procedures for construction works.

It is important to understand the following in advance:

1. Who prepares the design.
2. Which specialists are involved.
3. What documents are required for submission.
4. Which sections are mandatory.
5. What the local authority checks.
6. What the timeframes for approvals might be.
7. What work cannot be started without the necessary authorisation procedures.

7. Visado and review of project documentation

In some cases, the project is reviewed by the Colegio de Arquitectos. For example, the Colegio de Arquitectos de Málaga states that the visado involves checking the formal integrity, consistency of documentation and town planning parameters of the project, whilst technical responsibility remains with the architect who designed the project.

Electronic procedures relating to town planning and building applications/permits.

Project visado, verification of formal integrity, consistency of documentation and town planning parameters of the project.

This is important for the client because the project must not be a collection of disparate files, but a coherent set of documents.

The following must be checked:

1. Whether all sheets and sections are included in the project.
2. Whether there are any inconsistencies between the plans, elevations and sections.
3. Whether the dimensions match.
4. Whether the project complies with town planning conditions.
5. Whether it is clear which drawings to use for construction.
6. Whether an accurate cost estimate can be drawn up based on the project.

8. Common mistakes during the design phase

In practice, problems often arise not because of a bad idea, but because of insufficient planning.

Common mistakes:

1. The project is drawn up without taking the actual budget into account.
2. The site is not inspected before design work begins.
3. Structural engineers and other engineers are brought in too late.
4. The visualisations do not match the technical capabilities.
5. The site’s gradient is not taken into account.
6. Access for machinery is not properly planned.
7. Space for equipment is not allocated.
8. Materials are not agreed upon before the cost estimate is drawn up.
9. Many decisions are left to be made ‘on site’.
10. The design is not reviewed together with the construction team.

The most costly mistake is to start construction with an incomplete design. In such cases, the project turns into a constant process of making decisions on the spot.

9. What to check before moving on to the cost estimate and construction

Before calculating the final cost estimate and planning the work, you need to ensure that the project has been sufficiently developed.

Minimum checklist:

1. The site has been assessed from a technical and town-planning perspective.
2. The architecture is suited to the site conditions.
3. The structural design is clear.
4. The engineering systems have been planned in advance.
5. Materials have been specified, at least at a basic level.
6. There is a clear understanding of complex components.
7. The scope of work can be calculated.
8. There are no obvious conflicts between the various disciplines.
9. The design can be used for scheduling.
10. The construction team understands how to implement the solutions on site.

At STRUCTONIX, we view a design not merely as an architectural concept, but as the foundation for the future construction project.

The STRUCTONIX Approach

Our aim is to identify in advance any technical issues that may affect the cost estimate, timetable, design and quality of execution. The better a project is prepared before work begins on site, the fewer reworks and unexpected costs arise during the process.

A well-thought-out project helps us to build not ‘on the fly’, but according to a clear system: the plot, architecture, structure, engineering, cost estimate and sequence of works.

In the following articles, we will examine the cost estimate approval stage, groundworks, the foundations and the construction of the building’s structure.

Stay tuned and keep an eye on updates to the STRUCTONIX blog.