Why we publish these. Most of the grief in a self-build does not come from the construction. It comes from starting with the wrong number in your head. Someone works out the cost by multiplying square metres by a price they read somewhere, and finds out six months later that the town hall, the site works, the VAT and the contingency were missing.
These tools exist so that does not happen. They come out of questions we are asked every week.
Total construction cost calculator
It adds up every real item: the house itself, the professional team, the taxes of your specific town hall, the works outside and inside the plot, the extras and the contingency. With the ICIO rates and permit fees of thirty municipalities, which run from 3,4 % in Guadarrama to 7 % in Majadahonda. That is not a small detail.
You get the answer in two scenarios — a studio design to a good standard, and a high standard with interior design — and an explanation of where every euro comes from.
What it costs to have us do it
The complete professional team for a detached house starts at 26,000 € plus VAT, and we bill per square metre rather than as a percentage of what you spend building. That difference matters more than it sounds: we explain why on the fees page.
And if you would rather see the work first: twenty floor plans of houses we have built, from 136 to 1,138 m², each with its area and its town.
A planning report on your plot
Before you buy land it is worth knowing what may be built on it. You send us the land registry reference and we send back a report with the buildable floor area, the maximum footprint, the setbacks, the permitted height and any warnings we see: protected status, easements, rights of way or anything else that is going to complicate the project.
It is the most expensive mistake in a self-build, because by the time you find out you have already signed. And it is the only one with no fix.
If the ground looks difficult
Steep slopes, made ground, an unclear history or rock near the surface change the cost of foundations and retaining structures. That is what the soil survey is for, and why it is done before anyone designs. The calculator includes it as a separate item, at category C-0 or C-1 depending on whether there is a basement and on the floor area, which is what the Spanish building code requires.
The Spanish paperwork, explained
Every document and every step of a build, with the rule that requires it and what changes in Madrid. These guides are in Spanish for now; we are translating them. If there is something specific you need to understand before then, ask us and we will explain it.
Frequently asked questions
Do I have to register to use them?
No. The calculator works without you leaving any details at all. We only ask for an email address if you want the breakdown sent to you as a PDF, and that is optional.
Is the data reliable?
The ICIO rates and permit fees are taken from the municipal tax ordinances in force, verified one by one. Where we could not verify a fee, the tool says so and leaves it out rather than inventing a number.
Does it count as a quotation?
No, and the tool says so itself. Without real measurements, the characteristics of the plot, the position of the utility connections and defined finishes there is no exact price. It is there to show you the order of investment and which items you cannot forget.
Does it work outside Madrid?
The cost structure does. The municipal taxes built into it are those of thirty municipalities in the Madrid region; elsewhere you will need to check the ICIO rate and the permit fee at your own town hall and add them.
Are you familiar with buyers who live abroad?
Yes. A good part of the work in Marbella, Estepona, Ibiza and Mallorca is for owners who are not resident in Spain. The calculator is useful precisely there, because the taxes and the professional fees are the part a foreign buyer has no way of guessing.
Would you rather we looked at it together?
Tell us where the plot is, what house you have in mind and what stage you are at. If you have not bought the land yet, better still: that is the moment when most can be avoided.