The average person does not know all the parameters and technicalities used in architecture and construction. One of those unclear points is related to surfaces. Built surface versus useful surface, what are they if they are not the same. What does one refer to, what does the other refer to. In our daily life with clients who trust us Modular Home, we talk about built surface and useful surface, parameters that we use in the designs of our modular homes. Today we explain what each of them is.
Surfaces in Architecture
The truth is that in Architecture and in the real estate branch you can find references to various types of surfaces. They will tell you about built surface, useful surface. But also available surface, computable surface... This being the case, we may sometimes have doubts as to whether or not a house with ninety square meters of useful surface is smaller than one with one hundred and ten square meters of constructed surface. And in this case, for example, everything will depend on the layout of the house. But to understand this question we must know what each surface is and how it is calculated.
How many surfaces are there in a building?
Although we are dedicated to the construction of modular prefabricated homes, in this explanation we are going to be more global. This is because the explanation is valid for any type of building. Let's get to it, in a building there are two types of surfaces. This is the useful surface and the constructed surface. As the end user of that building, those are the two surfaces that we must understand and take into account.
Builded surface
The constructed area is calculated by measuring the polygon that delimits the covered space of the building. This surface includes the building enclosures. Also the surface occupied by the interior partitions, the structure and facilities of the building. And of course the spaces that will be used by the end user of the building. To have a global idea, this surface includes the one that will be used (walkable) and the one needed to execute the building (container).
Built surface with proportional part of common areas
In buildings subject to the horizontal property regime there is another parameter to take into account. The common areas are, for example, the floor distribution hallways, the stairs that connect each of the floors of the building. The elevator core or the portal. Facilities rooms, garbage room, the elevator box on the deck, etc. All those areas likely to be used by the entire community. Thus, in these cases, the concept of built surface with a proportional part of common areas is widely used.
Returning to the example used in the surfaces in Architecture, it would be necessary to know whether or not the one hundred and ten square meters were with their share of common areas. Well, in addition, each property that makes up the building community, registration units, has a participation coefficient. This coefficient is established in the statutes of the community of owners. There are cases in which it has a different coefficient. Well, this coefficient is used to allocate to each registry unit its corresponding proportional share of common areas.
Useful surface
To explain the useful surface we could say that it is the result of subtracting from the built surface, all the surface occupied by enclosures, interior partitions, structure and facilities. In short, you have the walkable surface that we talked about previously. A more technical explanation would be that it would be the result of measuring the interior polygon of the space we measured. The useful surface is therefore that which we are going to enjoy as users of the building.
Other questions about surfaces in Architecture
When they overwhelm you with concepts of available, or usable, or covered, computable, effective or official surface, know that they are tricks to say something and say nothing. Wow, they are trying to hide the data that is interesting. That is, the constructed area and the useful area, always demand these two data. For the purposes of purchasing a home, these are the two surfaces that interest the user of the home.
These two surfaces, built and useful, refer to covered surfaces. The surfaces of roofs, patios, or porches are computed individually. They must be recorded separately. That is, for example, a house of one hundred useful meters and twenty-five of porch or terrace. A very common trick is to inflate one of the two surfaces with these uncovered elements.
When we have rooms on the lower deck with sloping ceilings, we must know that in terms of constructed and useful surface area, only that which has a minimum height of one and a half meters or more should be measured. In other words, anything that leaves a free height of less than one and a half meters is not considered useful surface. It is evident that we can put these spaces to some use, but for the purposes of calculating surfaces they should not be measured.
