▲ Renovation type · Basement & semi-basement
PLAN N°KLD-2026 / SCALE 1:50 / 06.2026
Basement or lower ground floor drawings across the Netherlands
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 €1,849 incl. VAT, with construction and soil conditions accounted for from day one.
A basement or semi-basement is a waterproof space below or partly below ground level where structure and groundwater always play a role. The complete drawing with design basis costs from €1,849 incl. VAT and Tekenpunt plans delivery by arrangement (rush available for a surcharge). An environmental permit is almost always needed, allow 8 weeks for the decision period. You follow your entire application live in your own online file, from quote to delivery.
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.
123456
1
Waterproof concrete tank (basement box)
The complete watertight concrete shell you live in. The heart of every basement: it must withstand ground and water pressure and remain completely dry.
2
Sheet pile / cofferdam
The temporary wall that holds back the ground during excavation. Crucial next to an existing building to prevent subsidence.
3
Floor + foundation connection
The basement floor and its connection to the existing foundation. This is where the structural calculation is most critical.
4
Walls with water barrier
Basement walls with a built-in water barrier against groundwater. Detailing of joints and penetrations is decisive for a dry basement.
5
Staircase / access
The connection to the upper dwelling. Custom positioning and pitch angle, often the trickiest puzzle piece in an existing property.
6
Sun tunnel, garden window & ventilation
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.
§02 Quick check
Do you need a building permit?
Four questions, about 30 seconds. No obligation.
1
Is it a new basement or deepening an existing one?
2
Does the basement go under the house or under the garden?
3
Is your property a (national) listed building?
4
Do you know the groundwater level at your location?
Permit almost certainly required
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 €1,849 incl. VAT. Request a no-obligation quote for your specific situation.
§03 Costs
Calculate your basement price
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.
Only then the construction itself, via a contractor or basement builder (not with us):
Construction costs basement± €81,000
* 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.
Amounts shown are incl. VAT (consumer price); the amount below the total is the amount without VAT. Your personal quote always shows the exact total price.Amounts shown are excl. VAT; the amount below the total is the amount incl. VAT (consumer price). Your personal quote always shows the exact total price.
§04 Packages
Choose your package
Every package includes the drawing. Add structural calculation or the full permit route.
Drawing
from€1,849 incl. VAT
Existing + new floor plans, elevations, relevant sections and site plan to scale
PDF + DWG files, suitable for the municipality and your contractor
Our own structural engineers and drafters work per Eurocode and check against the Bbl building code; every drawing and calculation is reviewed internally by our checkers before release.
930 projects since 2016, and 90% clears the aesthetics review (welstand) on the first pass — meaning: no design change needed after the municipality's first assessment.
4.9 out of 10 reviews for this type of renovation (15 projects since 2016).
§05 Three variants
Which basement suits your home?
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.
Deepening an existing basement
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.
PermitUsually
Extra space10-25 m²
StructureRequired
Priceon quote
New basement under the property
Excavating a completely new basement under your existing home. Maximum space gain, but involving a construction pit, sheet piling and a rigorous structural assessment.
PermitRequired
Extra space25-50 m²
Permit process8+ wk
Priceon quote
Basement with daylight
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.
PermitRequired
DaylightFull
Permit process8+ wk
Priceon quote
§06 Comparison
Basement vs alternatives
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.
Basement
Design from €1,849 incl. VAT
Always structural work and groundwater
10-50 m² beneath the property
Delivery planned by arrangement
Garden and facade remain intact
Extension
Design from €599 incl. VAT
Often partly permit-free
10-25 m² on the ground floor
Does use garden space
Roof extension
Design from €649 incl. VAT
Permit always required
20-50 m² full additional floor
8-week permit
Does the building height change
§07 Permit depends on situation
What applies where?
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.
Site plan
Type
Permit
Price
Soil / groundwater
Deepening existing basement, dry
Deepen
Usually
On quote
Favourable
New basement under property, dry
New
Required
On quote
Favourable
New basement, high groundwater level
New
Required
On quote
Attention
Basement with daylight
Basement level
Required
On quote
Attention
Listed building / protected townscape
Custom work
Required
On quote
Very strict
§08 Case study
Example project: basement beneath a villa
CASE · BLOEMENDAAL · 05.2026
New basement under an existing 1930s villa
Example project · beneath the home · permit required · wellness + storage space
+35 m² space
1 permit
Fixed price our design
Fast drawing
FOR
SKETCH
STRUCTURE
NA
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 extra living space under the house, a dry and well-ventilated basement, and a permit granted in one go. Drawing planned by arrangement; permit within the decision period.
§09 Additional info
Groundwater, financing & structure
A basement is a major, permanent investment with significant space gains. What you need to know in advance.
Groundwater first
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 WELL
Structural calculation required
Excavating 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 2026
Renovation mortgage
A 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).
Often 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.
Q02What does a basement drawing cost?
A complete basement drawing with structural principles starts from €1,849 incl. 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.
Q03Is groundwater an issue with a basement?
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.
Q04Is a structural calculation mandatory?
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.
Q05How long does it take?
We plan the drawing by arrangement; rush is available for a surcharge. A basement almost always requires a permit; allow 8 weeks for the municipal decision period, which can take longer with soil investigation or a structural review.
Q06Do you work across the Netherlands?
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.
◆ Kelder in de praktijk
15 basement conversion projects since 2016
10 clients rated their basement conversion project with an average of 4,8 out of 5 stars. A few of their comments:
BJ
Bram J.Zoetermeer · Basement
★★★★★
Very professional firm. The construction drawings for our basement conversion were highly detailed. Exactly what we were looking for, and the contractor could get straight to work.
Basement
PP
Peter P.Wassenaar · Basement
★★★★★
We wanted to build a basement conversion in Wassenaar. Tekenpunt guided us well from start to finish, and we could get straight to work with the contractor.
Basement
MD
Maaike D.Utrecht · Basement
★★★★★
Tekenpunt drew up our basement conversion perfectly. Thank you!
A fixed-price quote as soon as possible. Free check on whether a basement is feasible for you, including a first estimate of construction and groundwater. No obligation.