Each construction starts with a concrete foundation, and it depends on you if this foundation will be almost on ground level or 10 feet deeper. To be exactly: If your new house will have a basement floor or not. At least, if we think about a single family house, because large commercial building can have a lot of basement floors in the underground. That’s why one decision is essential: Do I need a basement or not? We try to clear up your decision.
Basement: the cons
First of all we have to talk about building costs. A basement increases almost always the costs of your construction significantly. There are some reasons: Firstly, there is extra excavation work necessary, which results container costs and cartage. Then, a massive or rocky underground may increase the excavation work. Finally, an elevated water table makes necessary an additional and expensive insulation. Therefore it is important to consult a specialized ground planner about local ground conditions to avoid surprises.
Also basements are frequently affected of humidity and mould. That can be caused by poor ventilation of missing windows in the basement. Especially in areas with high water table and rainy climate a low ventilated basement can cause serious damages to the interior, and to the building fabric, too. Also human condensate brings humidity to the basement.
Often imperfect work and low-priced insulation materials are to blame for moisture damages in the exterior walls, which later affect the whole basement area if they are not be fixed soon.
In the end you should conscious of the low lighting in basements. Even with some cellar windows you won’t have sufficient daylight to light up the room, which means to plan enough sockets and lamps for a correct lighting level.
Basement: the pros
There is a main reason to build a basement: to obtain additional place in your house. If you live in a city, probably ground prices are high or your new construction is limited in the available base area because of the little plot of land or law concerning neighbours. Often height limits doesn’t offer to add a additional floor, therefore a basement floor could be a solution.
A second good reason for a basement floor is the usage that you will give. For example, there are some use that really should be downstairs, if possible. Underground level keeps a constant temperature during summertime and wintertime, it makes it a perfect place for food and wine, fitness activities and general storage. Also a sauna place can be included easily. If you think about the quantity of technical installations and the heating system, which a modern house includes, a basement makes absolutely sense.
Even a little home-office or a guest room can be situated in the basement, there are modern solutions to bring daylight and air to the underground with special cellar windows. Of course, it can be used as little housekeeper apartment, too.
Let’s come to the technical reasons. Firstly, it allows you to control and repair easily any penetration of moisture from outside, without any expensive excavation work. Also a basement makes sense in sandy grounds: a reinforced ground plate can nearly reach the price of an economic basement.
Last, but not least: you shouldn’t forget that a house with basement will always have a better resale price as a house without basement.
We provided the main Pros and Cons of a basement. There doesn’t exist a general solution to make the right decision. More likely you have to proof each project with your architect to know if a basement is worth or not.
Of course only yourself are able to analyse your personal requests. How much space will need all house technique? Do you need a fuel store or do you run your house self sufficient with renewable energy? Will you really use a fitness room? Only if you really make use of the extra level, the extra costs for construction, lighting and heating would be compensated. If not, try to include some small store space in the ground floor or in a small annex.
Your architect’s task is to check technical feasibility due to ground conditions and level of water table. He also can give you recommendations that depend on local and geographic characteristics.
Finally, be aware of the risks of humidity and make sure that the underground area is well ventilated.