Gain extra living space without sacrificing a single square metre of garden or building height: beneath your home. A basement or semi-basement is the most complex renovation, as structural design and groundwater are always factors. We produce the complete drawing with structural principles from €1,995, with construction and soil conditions accounted for from day one.
A basement or semi-basement is a waterproof space below or partially below ground level where structure and groundwater are always relevant factors. The complete drawing with design parameters costs from €1,995 and Tekenpunt delivers within 4 weeks (express 1-2 weeks). A building permit is almost always required; allow 8 weeks for the decision.
It is structurally the most demanding renovation: everything revolves around a watertight concrete box, a safe excavation pit and the connection to the existing foundation. These are the elements we draw.
The complete watertight concrete shell you live in. The heart of every basement: it must withstand ground and water pressure and remain completely dry.
The temporary wall that holds back the ground during excavation. Crucial next to an existing building to prevent subsidence.
The basement floor and its connection to the existing foundation. This is where the structural calculation is most critical.
Basement walls with a built-in water barrier against groundwater. Detailing of joints and penetrations is decisive for a dry basement.
The connection to the upper dwelling. Custom positioning and pitch angle, often the trickiest puzzle piece in an existing property.
Daylight via a light shaft or, for a semi-basement, a garden-facing window, plus mechanical ventilation against moisture. This determines whether the basement truly becomes habitable.
Four questions, about 30 seconds. No obligation.
A basement almost always affects the structure, groundwater and municipal soil regulations, so a building permit is in practice usually required. We handle the drawing, the structural principles and the application. From €1,995. Request a no-obligation quote for your specific situation.
Indicative calculator. The drawing is a fixed price; the construction work (groundwork, concrete shell, finishing) is carried out separately by a contractor or basement specialist.
* We handle the design, structural engineering principles and (if required) the permit. The construction work (groundwork, concrete shell, waterproofing, fit-out) is carried out separately by a basement contractor; that figure is an indication of approximately €2,500 to €4,000 per m². Request a quote for the exact drawing costs.
From an existing basement that you deepen to a full-height basement with daylight. We advise on what is structurally feasible and what the groundwater level allows.
You already have a (shallow) basement and want to deepen it to full standing height. The quickest route, but the foundation and groundwater demand full attention.
Excavating a completely new basement under your existing home. Maximum space gain, but involving a construction pit, sheet piling and a rigorous structural assessment.
A semi-sunken basement with a garden-facing window or sunken patio: a true garden room or kitchen-diner full of daylight. The highest-quality end result.
A basement is the way to gain square metres without affecting your garden or building volume, but it is the most demanding intervention. Here is how it compares to an extension and a roof extension.
For a basement, the type of intervention, the groundwater level and any listed-building status determine whether (and how strictly) you need a building permit. A few typical situations.
Example project · beneath the home · permit required · wellness + storage space
Challenge: A family in Bloemendaal wanted extra space for a wellness area and storage, but the garden and streetscape had to remain undisturbed. A basement beneath the existing villa was the only option, with the foundation and groundwater level as major unknowns.
Our approach: Together with a structural engineer we mapped the existing foundation and established the structural principles for the excavation pit and the watertight concrete tank. The groundwater level proved favourable. We delivered a complete, dimensionally accurate drawing that both the basement contractor and the municipality could work with straight away.
Result: 35 m² of additional living space beneath the property, a dry and well-ventilated basement, and a permit that came through first time. Drawing in 4 weeks, permit within the decision period.
A basement is a major, permanent investment with significant space gains. What you need to know in advance.
The groundwater level determines whether a basement is feasible and how robust the waterproof structure needs to be. If in doubt, we recommend a soil survey before finalising the starting points.
ADVICE · GROUNDWATER LEVEL + MONITORING WELLExcavating beneath or beside a home affects the foundation. A structural calculation is therefore standard for a basement; we establish the design parameters and collaborate with a structural engineer.
NORM · EUROCODE / BBL 2026A basement significantly increases the living area and often the property value. The costs can be co-financed through a renovation mortgage (up to 106% of the value after renovation).
BRON · NHG.NL 2026Often yes. A basement beneath the existing ground level of your property can sometimes be permit-free, but due to groundwater, structural requirements, and municipal soil regulations, a building permit is usually required in practice. A semi-basement with natural light and a new basement beneath the dwelling are almost always subject to a permit. We check your situation free of charge.
A complete basement drawing with structural principles starts from €1,995 (excl. VAT). This is the most complex renovation we draw because it always involves a structural and groundwater question. The construction itself (by a contractor or basement specialist) is indicatively between €2,500 and €4,000 per m².
Groundwater is the most important consideration for a basement. The basement shell must be watertight (a concrete tank with water barrier) and where the water table is high the structure must resist upward pressure. We always include the groundwater level in our design principles and refer to a soil survey where necessary.
For a basement, almost always. Excavating beneath or alongside an existing home directly affects the foundation and structural stability. A structural calculation is therefore standard for a basement design; we handle this in collaboration with a structural engineer.
We deliver the drawing within 4 weeks (express: 1-2 weeks). A basement almost always requires a permit; allow 8 weeks for the municipal decision, and ground investigation or a structural review may extend this further.
Yes. We draw basements and semi-basements across the Netherlands. We handle the drawings remotely, submit any required building permit to your municipality and take into account local soil and groundwater rules.
A fixed-price quote within 1 working day. Free check on whether a basement is feasible for you, including a first estimate of construction and groundwater. No obligation.