Things to consider before building a basement

Each client for whom a building is being built, whether if it is a small single family house or a large commercial building, has to take a main decision before construction work begins: If he wants a basement floor or not. Excavation and foundation planning depend on this. We try to help you getting to know advantages and disadvantages.

Pros of a basement

Initially, we will talk about the advantages. Of course, a basement offers an additional space, which counts especially in cities with high ground prices, or if the plot of land available is small. Also building regulations may limit the maximum height of a house, in this way the owner can gain a whole floor.

The second important Pro is the fact that the basement floor is in the underground. That means that it is cool in the summer and well moderated in the winter time, which makes it a perfect place to store wine and food, or for your workout routine, or just a place for storage or a sauna.

But there are much more reasons, too: Contemporary buildings and modern houses have to install more and more technical equipment, sustainable energies make necessary solar tanks, heat pumps and heating energy depots. Washing machines and cleaning devices also may be stored in the basement, instead of occupying place in the upper living place.

Speaking of additional place, one shouldn’t forget that the basement gives also place to guests or a live-in-housekeeper. The underground floor can save lives in case of climatic catastrophe like heavy storm.

Thinking practical, a basement can avoid damages of humidity and even offers easier access in case of penetration of moisture in the exterior walls.

If the building ground is unstable, for example sandy, the price of a reinforced ground plate can nearly be the same as the construction of a cheap basement, which makes it even more economic as in massive grounds as rocks, for instance.

If you think about the increase in value, you should know that normally the resale price of a building with basement is clearly higher than of one without it.

But let us come to the disadvantages.

Cons of a basement

Of course, the extra cost that results a basement can be the main reason to forgo it. May be there are difficult ground conditions such as high water table or extremely hard ground such as rocks, deep excavation may elevate construction costs significantly. Also lavish insulation is necessary.

Consult your planner to proof ground conditions and ground-water in advance to know if there are additional complications could be expected. That avoids later surprises in the estimation of the entire building budget.

One of the main problems of basements may be humidity and mould. That comes of lack of ventilation, normally basements don’t dispose of windows to ventilate and dry the interior air. This is a defect that affects a lot of houses with basements. It goes worse in areas of a high water table, which brings permanent moisture to the exterior construction.

Also the human condensate may be enough to produce humidity and mould in the interior of your basement floor. Check to get enough ventilation using controlled mechanical ventilation systems and dehumidifier.

Furthermore, often construction companies try to save money using low quality insulation materials in the underground, because “nobody will be aware of it”. Indeed, damages will appear years later, when warranty expired. Incorrect insulation is the most frequent complaint in the construction sector, always make sure that your architect takes control of it!

Finally, take in mind that the lighting of a basement always is less than in upper floors. You need to use artificial instead of natural daylight, which means a good planning to provide enough lamp sources and sockets to fulfil the demands on a correct illumination.


If you want to hear a general “yes” or “no” in respect of basements, we need to disappoint you. There is not. You need to check your local conditions with your architect to make the right decision.

At the beginning, you have to analyse your personal circumstances and requests. Is there a clearly need and a practical use in your daily life for a basement? Do you need a spacious storage or could be a small upper stuff room enough? Will you and your family practice fitness or other hobby regularly or just once a week? Remember, you have to clean this extra space, illuminate and heat it, and it costs money extra to build it. For instance, a subscription in a fitness studio can be more economic in the end.

Next, the geographic properties have to be thoroughly checked to make sure that the construction of a basement makes sense with regard to expenditure, safety and costs. Problems may be caused by high ground-water level, pressing water or rocky grounds. Follow the recommendations of local engineers of ground who know about risks and extra fees.

Also think about principal negative aspects of basements like the risk of humidity, mould, flooding in river areas and difficulties to illuminate the subterranean floor.

Having in mind all Pros and Cons, a basement may offer a great value to amplify your living space and to store technique. Make sure that you derive a real benefit from it in your daily life.