Design Process
How to find a plot of land to build a house?
Clients often come to our studio while they are still searching for a plot of land to build a house, with many questions and sometimes without really knowing how to assess the different options.
We always try to provide clear guidance and, in most cases, we get actively involved in the process.
Finding a plot of land to build a house is one of the most important first steps in any home-building project. Choosing where we are going to build a house is one of the most essential ancestral human needs, and making the right choice will be decisive for our quality of life.
To begin with, we always recommend considering three basic criteria that any plot must meet. Once these requirements are met, we can assess in more detail the characteristics and conditions of the plot to build on. These are requirements that cannot be solved in any way through construction, and they will determine both the environmental and ecological quality of our home and the construction cost.
So, let’s look at what is essential to assess before buying a plot of land:
1. Sun
For us, it is the essential and primary element to consider. The sun is the main driver of passive architecture: an eco-friendly home is oriented to maximise solar gains during the day and thus achieve natural warmth. But the sun is also a source of health; a sunny home will have fewer damp issues and can operate for most of the day with natural light.
What is the best orientation?
In the Northern Hemisphere, the best orientation is south. This means that most of the home should be able to open towards the south, and therefore it will be important to visit the site and check that this is indeed possible.
As for east and west orientations, these will also be important. An east-facing façade will receive early-morning sun—an interesting feature for bedrooms—and a west-facing façade will receive afternoon sun, which may be desirable in winter when the sun is lower and can therefore penetrate the home, making use of the warmth until the last hours of the afternoon.
Another important check related to orientation is ensuring there are no obstacles that prevent sunlight from reaching the plot, such as trees, nearby buildings, differences in slope, etc.
CASE
A few weeks ago, we went to visit a plot with a client who was weighing up the purchase decision.
On the plan, the plot had an excellent, fully south-facing orientation; however, when we visited it on site, it turned out that the plot was on the eastern slope of the mountain and, despite being perfectly oriented to the south, the mountain itself, along with tall trees and nearby buildings, prevented it from receiving sun beyond midday.
For this reason, it is so important to visit the plot with a compass and understand how the sun falls throughout the day, to know whether it will be possible to take advantage of it to heat our home.
Building a house today cannot be understood without the free and unlimited energy the sun provides. Therefore, this is the indispensable premise to consider before buying a plot of land.
Once we have confirmed that we do indeed have sun, let’s look at the other factors we must consider, which will define the construction cost of the home.
2. slope
If you have already been researching plots, you will have noticed that flat plots are more expensive than sloping plots. This is not only due to convenience, but also because building on a sloping plot significantly increases the cost of our home.
A sloping plot will require major earthworks and probably the construction of a retaining wall before starting to build the house.
Earthworks and the construction of a retaining wall represent an additional cost to take into account.
3. SOIL BEARING CAPACITY
Finally, perhaps the least well-known factor—and one that is not usually considered when assessing the decision to buy a plot—is its bearing capacity.
We need to know what type of subsoil we have beneath our future home, as the cost of building on rock is not the same as building on soft ground.
In general, the criterion is: the harder, the better, because the more resistant the ground is, the less substantial the foundations of our house will need to be. But be careful: if we need to build a basement under our home, it may be advantageous for the ground to be soft, because excavation will be more economical. In any case, it is best to consult a professional before making the purchase decision.
How can I find out my soil’s bearing capacity?
We always recommend that all our clients who are about to buy a plot invest in a geotechnical study.
A geotechnical study is carried out by a geologist and will provide information about the type of ground beneath our feet. The geologist comes with drilling equipment and performs tests at different points, determining the depth of the load-bearing layer where the foundations of our home should be placed. If this layer is too deep, we will need to excavate and build deep foundations to reach it.
A geotechnical study can cost around €800–€1,000. In some cases, the previous owner or the estate agent selling us the plot may already have one, but in that case it will be necessary to assess its reliability.
At the studio, we always recommend that you consult us at this stage, as this allows us to review the study and assess foundation costs before making the purchase decision.
Soil bearing capacity is a characteristic that is not usually taken into account when assessing the purchase of a plot, and it will be just as important—or even more so—than the slope in determining the construction cost of the home.
In any case, it is important to bear in mind that, just as solar exposure is a factor we cannot solve in any way, both the slope and the soil bearing capacity are characteristics that will only increase construction costs, but that may sometimes be worth considering.
From here, to find a plot of land to build a house, we can consider many other factors such as location, vegetation, neighbouring buildings, good public transport connections, and even underground water currents, among others.
In later articles we will cover the remaining factors, but none of them will be as decisive for construction cost and the quality of our home as the three mentioned above.
how much does a plot of land cost?
While the price of a house is easy to measure, since the construction cost per square metre depends largely on the quality of the materials and building systems, and on whether they are eco-friendly or not.
The price per square metre of a plot is highly relative and depends on where it is located. A plot with the same conditions is not worth the same if it is well connected to a large city as if it is isolated. Likewise, the price increases the better the views and the better the solar exposure, so we must assess what is most important to us in order to find a plot that suits our needs.
If you are in the process of searching for a plot, do not hesitate to contact our team to receive advice on all the factors to consider before making the purchase decision.