They are blooming on all the roofs of Luxembourg: the seated dog windows increase living space and attic volume. Would you like to use this technique to convert your attic or bring more light upstairs? Then you've come to the right place.
Contents:
What is a seated dog opening and why choose this solution in Luxembourg?
This is a special type of skylight, distinguished by its slope, which is reversed in relation to that of your roof. Generally speaking, your roof will have a fairly steep slope. Where there is a window, it will either be flat or much less steep.
Unlike other types of skylight (hipped dormer, crawl dormer), the dormer offers natural protection against frequent bad weather while maximising light during the winter months, and creating additional living space in the attic.
That's why this solution is so popular for renovation projects in Luxembourg. It provides additional attic space on a limited budget.
Why do Luxembourg homeowners build sitting dogs in their roofs?
- Because it increases the value of their property (making the attic space habitable and more spacious)
- Because it offers better thermal comfort (windows and reinforced insulation prevent overheating in the attic)
- Because this type of window offers a panoramic view of the landscape, unlike a traditional Velux window, which allows you to look only at the sky
What authorisations are required?
In Luxembourg, the installation of a sitting dog is subject to specific regulations that differ from those in neighbouring countries.
This type of modification must fall within the scope of a planning permission, There are several reasons for this:
- Because the modification alters the external appearance of the building
- Because it increases living space (if the ceiling height after creating the seated dog is high enough)
- Because it can operate in protected sectors, where local authorities can give their opinion on the aspect of renovation
Before embarking on your project, it's important to understand the steps you need to take, as they may involve additional costs (architect's office, example of visual integration, ground plans, etc.). Make sure you check with your local planning department beforehand.
The different types of structure for your project
There are different styles of sitting dogs:
The Jacobin seated dog: the traditional choice
This is the most common style in Luxembourg. This is a gabled dormer with a triangular pediment that blends in perfectly with the traditional architecture of Luxembourg roofs (making it a favourite choice, particularly in rural villages and historic districts).
The materials are generally natural slate, and the dimensions are generally 80x120cm (the size of a standard window).
This type of opening generally makes it possible to fit large bay windows and bring a lot of light into the converted attic space. They can be found in both renovation and new-build projects.
The nasturtium sitting dog: elegance and discretion
It's a good compromise between tradition and modernity. The top of the window has a 3-sided roof. The front hip maximises interior volume and the overall structure minimises wind resistance.
This type of dormer window fits in well with projects where the roofs have several slopes.
Other possible solutions
There are as many sitting dog structures as there are owners. These other options are just a few examples:
- A sitting dog with a flat roof: With its very low slope (3-5°), this solution blends in perfectly with cubic and minimalist architecture.
- A dormer window : This elongated version spans several metres of roof, creating a beautiful panoramic opening.
- An asymmetrical sitting dog: This type of structure offers a bold design that plays on volumes and perspectives, ideal for architect-designed homes in upmarket residential areas.
The price of a sitting dog in Luxembourg in 2026
Here are the average prices in Luxembourg in 2025, including installation and materials:
| Sitting dog type | Average price Luxembourg | Special features |
|---|---|---|
| Standard Jacobin Sitting Dog | 5 000 € - 10 000 € | Traditional materials, standard insulation |
| Sitting dog nasturtium | 7 500 € - 13 000 € | More complex structure, carefully finished |
| Top-of-the-range sitting dog | €15,000 – €25,000 | High-quality materials, reinforced insulation |
| Contemporary made-to-measure solution | 30 000 € - 45 000 € | Unique design, integrated home automation |
Good to know: Prices vary greatly from one company to another. Before taking the plunge, it's a good idea to ask for an estimate. free quotation for this type of renovation.
Note that the final price will also depend on a number of criteria and constraints (type of roof, age of roof, type of cladding/tiles, etc).
FAQ: Frequently Asked Questions
What is a seated dog window and why choose it in Luxembourg?
This is a dormer window with an inverted slope in relation to the roof, offering natural protection against the weather that is common in Luxembourg. It maximises light during the winter months and creates additional living space in the attic. This very popular solution increases the property's value while offering a panoramic view of the landscape, unlike a traditional Velux window.
Do I need planning permission to install a sitting dog in Luxembourg?
Yes, this requires planning permission in Luxembourg, as it changes the external appearance of the building and increases the living area. This modification can also take place in protected areas where the municipal authorities give their opinion on the appearance of the renovation. It is essential to check with your local planning department before starting the project.
What are the different types of sitting dog available?
The Jacobean seated doghouse is the most widespread style in Luxembourg, with its triangular pediment harmonising with the traditional architecture, which is generally made of natural slate. The nasturtium dormer offers a compromise between tradition and modernity, with its 3-slope roof maximising interior volume. Other options include the flat-roofed dormer, the banded dormer or the asymmetrical dormer for contemporary architecture.
How much does a sitting dog cost in Luxembourg?
The price of a seated dog ranges from €5,000 to €45,000, depending on the type and finish chosen, including installation and materials. A standard Jacobean seated dog costs between €5,000 and €10,000, while a nasturtium model costs between €7,500 and €13,000. Top-of-the-range, made-to-measure solutions can cost from €15,000 to €45,000, with high-quality materials and integrated home automation.