Prefabricated houses, the solution of the future?
Although prefabricated houses are nothing new, the growing sophistication of industrialized systems and the lack of space in large cities make them topical again. But are they as ideal as they seem?
The densification and the increase in the price of land in large cities have caused many to consider acquiring land in the rural outskirts and building their own house. The demand for a tighter price, and the possibility of not having to suffer the usual setbacks of a traditional work, has brought back to the panorama the model of prefabricated construction that, although it has more than half a century, it seems that it is acquiring in Europe the vigor that it had never enjoyed before.
What is a prefabricated house
To begin with, it is convenient to differentiate between prefabricated houses and modular homes. A prefabricated house is one that is built entirely in an industrialwarehouse. Then it moves to its final location, where it is permanently located after a brief construction process.. . Unlike mobile homes (such as a roulotte, for example), prefabricated houses are real estate and must remain in place forever.
On the other hand, there are also modular homes,whose commissioning is done in situ, but they have the advantage that most of their pieces are already prefabricated in advance, so that the assembly is reduced to the assembly of modules, as if it were a giant Lego. This typology has the great attraction of being easily expandable in the future, since it is enough to acquire and assemble new modules.
Dismantling myths about prefabricated houses
There are numerous prejudices against prefabricated houses, as if by the fact of having been built in a workshop they are not “real” houses, or they have to necessarily accuse a worse quality. But the truth is that there is nothing further from reality, since in most cases it is impossible to distinguish between a prefabricated house and one that is not, having cases of prefabricated houses with finishes of absolute luxury.
There is also a certain trap behind the headline that prefabricated houses are cheaper: while it is true that their manufacturing system implies a reduction in cost, and that there are specific models at very affordable prices, a prefabricated home is not much cheaper from a certain range of quality. Its average price in Spain is between € 800 / m2 and € 1,700 / m2,quite similar to that of any traditional construction. However, the vast majority of brands continue to defend that opting for prefabrication means a saving of between 20% and 50% compared to conventional systems.
In most cases it is impossible to distinguish between a prefabricated house and one that is not, although it may seem that choosing a house by catalog greatly limits the choice, there are numerous companies that offer a high degree of customization to design a custom home, being able to choose the client among all kinds of materials, distributions and finishes. The final quality of the property depends on the budget, so before judging a possible saving it is advisable to read the fine print, since many offers that say “for a price from”, end up being much more expensive as complements are added.
Finally, we must bear in mind that no matter how much prefabrication is carried out, there will always be a small commissioning process,since in the vast majority of cases it is essential to build a foundation in situ, in addition toconnecting the house with the urban infrastructure: the sewerage, the electricity network, of telecommunications, etc.
Advantages and disadvantages of prefabricated houses
Speed of execution
The indisputable attraction of a prefabricated house is the speed of its execution. The fact that the companies that manufacture them are so specialized facilitates their mass production,which considerably reduces their delivery time.
Most manufacturers guarantee a delivery time of five months, a figure much lower than that of a house built in the traditional way. This is due both to the optimization of industrial resources and the fact that there is total independence from meteorological factors (which often delay works outdoors), being built in controlled spaces.
Meeting deadlines and budget
Another of the great advantages of prefabricated houses is the dramatic reduction of unforeseen events during their manufacture. Being produced through a system that has already been refined and tested in a suitable environment, the surprises are the minimum and there is a practically total guarantee that the buyer will receive the keys to his home in the agreed term and without spending a cent beyond what was agreed.
Regarding its series production, calibrated to the millimeter, the prefabricated construction enjoys a very efficient optimization of resources,whichconsiderably reduces its ecological footprint. A system of this type generates much less waste and also less emissions, requiring much less transport of material to the site. If we also add that it also facilitates that the resulting houses obtain more efficient energy classifications, it can be said that, at least in theory, producing prefabricated homes constitutes a more sustainable model.
Conditioners of the terrain
While prefabricated houses enjoy many advantages, they also suffer from some drawbacks, the main of which is that they are only viable on very flat land.
At a time when a considerable volume of excavations and earth containments have to be carried out, the very concept of prefabrication becomes absurd. Therefore, this type of construction can not have basements,nor do they include any operation that has to do with the land they occupy, especially if it is steep. This does not mean that you can not opt for a hybrid solution, building the house in a prefabricated way and carrying out traditional works on the site, but in this case we would not be talking strictly about prefabrication.
By its nature, the planning of a prefabricated house must be done beforehand and in a very rigorous way; once closed, the layout does not support last-minute changes. Therefore, all decisions have to be very clear and taken in advance. In addition, there is a risk: prefabricated dwellings do not have an organic period of settlement.
In traditional construction, the weight of a building is progressively transmitted to the ground as the work progresses, making it possible to rectify it on the fly. However, a prefabricated house is placed on the ground at once, so any error in geotechnical forecasting can result in surprise settlements that lead to undesirable breaks or cracks.
Prefabricated concrete house of Homm
We must not lose sight of the fact that one thing is the speed of construction and quite another, the pace of legal procedures. At the end of the day, prefabricated or not, a house must comply with all existing regulations. Although the house may be ready in record time for industrial reasons, obtaining a building permit can still take even years, depending on the effectiveness of each Administration.
As a positive point, it should be added that most manufacturers already offer a team that is responsible for managing all these procedures as part of the order.
Should I buy a prefabricated house?
I analyze its details, it is recommended in the case in which the construction time is a determining factor.
Another possibility is that the customer is willing to give up a certain quality in favor of a critical decrease in price.
An attractive option is the plots away from civilization, due to the savings it entails in terms of transport of materials and maintenance of operators on the site. But be careful, because it is essential that it has good accessibility for road traffic; otherwise, the truck transporting the construction will not be able to deliver its goods.
On the contrary, there are cases in which it is not convenient to choose this option:
- On very sloping and uneven land or on plots of very low occupancy, which make it necessary to build underground plants. If we are looking for a house very adapted to the land and its vegetation,it is also preferable toopt for the traditional construction model.
- The price of land in urban environments is much more expensive, counteracting the possible savings derived from manufacturing. And urban planning regulations can excessively condition their personalization.