The ley del mono in Chile: the two regimes, the requirements and the running deadline

Quick answer: the ley del mono, the simplified regularisation act, is law 20.898, and it sets out a simplified procedure for regularising homes and extensions that were built without a permit. It has two regimes: up to 90 square metres with a tax appraisal of up to 1,000 unidades de fomento, and up to 140 square metres with an appraisal of up to 2,000. In both, the building must be from before 4 February 2016. Law 21.725 extended the deadline for filing applications to 31 December 2027, and there is a bill in progress to extend it further.

Almost every house in Chile has something that is not on the plans: an extension, an enclosed barbecue area, a room that went up when the second child arrived. As long as nobody looks, nothing happens. The problem shows up the day you need to sell, mortgage or inherit, and that is when the lack of final municipal approval stops being an administrative detail.

What final municipal approval is, and why it matters so much

Final municipal approval is the act by which the Municipal Building Department certifies that what was built matches the permit granted and complies with the regulations. It is the document that closes the cycle: first the building permit, then the construction, and finally the approval.

Without it, for legal purposes the building does not exist, even if you have lived in it for twenty years. That has very concrete consequences.

• The bank will not finance it. The valuation counts what has been approved, not what has been built, and the loan falls through or shrinks. We cover this in why the bank can block the sale.
• The price takes a hit. You can still sell, but the buyer discounts for the cost and the risk of regularising it. That is covered in whether you can sell a house without final municipal approval.
• Insurance may not cover what has not been declared or approved.
• You cannot subdivide or set up a condominium regime with buildings that have not been approved.
• You remain exposed to fines from the Municipal Building Department, whose amount and how to defend against them we explain here.

What the ley del mono is, by name and number

The nickname hides a specific law: law 20.898, which sets out a simplified procedure for regularising self built homes. Simplified means the permit and the approval are obtained in a single step, with fewer supporting documents and lower cost than the general route.

It is not an amnesty or a pardon. It is a procedure with requirements, and anyone who does not meet them is left out and has to go through the ordinary route. Nor is it permanent: it was born with a deadline and has been extended by successive laws. The latest, law 21.725, pushed the deadline for filing applications back to 31 December 2027.

The two regimes, which are almost never told apart

This is the source of almost all the confusion out there. The law does not have a single cap: it has two tiers, with different requirements, which is why you see contradictory figures everywhere.

In both cases the building must have been built or extended before 4 February 2016. That date does not move: it is not a matter of being so many years old, it is a specific day, and an extension made after that date does not qualify through this route, however small it is.

The detail that works in your favour and almost nobody knows. The appraisal that counts is not the current one: it is the one on the certificate from the Servicio de Impuestos Internos (the Chilean tax authority) for the first half of 2016. If your property increased in value since then, and most did, you still qualify using the 2016 figure. It is worth requesting that certificate before assuming you are excluded on appraisal grounds.

Who is left out

There are two exclusions that rule you out outright, and it is worth checking them before commissioning any plans.

• Having pending complaints for breach of planning rules before the Municipal Building Department or the Local Police Court. If a neighbour has already reported you and the proceeding is open, this route is not available while it remains active.
• Being located in a risk or protected area. If the land is in a flood zone, a landslide risk zone, or an area protected by the planning instrument, simplified regularisation is not available. How to check this is in how to find out if land is in a flood zone.

The file: what has to be submitted

The application is filed with the Municipal Building Department of the relevant commune, with the ministry's form and the supporting documents that go with it. Here is the list, and it must be signed by an architect or the competent professional, depending on the case.

Of everything on that list, proof of age is what holds up the most applications. It is worth gathering it first, because if you cannot prove the building predates February 2016, the rest of the file is of no use.

The deadline is running, and this time it has a date

31 December 2027 is the current deadline for filing applications. There is a bill in progress that proposes extending the deadline and adding a correction procedure with a single round of observations, to avoid the practice of successive rounds of observations that drags applications out. But it is only a bill: it is not law yet, and planning around an extension that does not exist is the most common way of being left out.

The practical takeaway is simple. Putting the file together takes time, especially the proof of age and the plans, and the Municipal Building Department can raise observations. Starting the process in the last six months is betting there will not be any.

If you do not qualify, there is still a way forward

Falling outside law 20.898 does not mean you cannot regularise. It means going through the general route: a building permit and final municipal approval, with the full project and payment of the relevant municipal fees. It is longer and more expensive, but it reaches the same result, and the breakdown is in how much it costs to obtain final municipal approval.

There are two situations where the problem comes earlier and has to be resolved first. If the property is not registered properly, regularisation of title comes first. And if what was built sits on rural land, the regularisation has to work alongside the rural construction rules, which are covered in how many houses can be built on a plot.

Frequently asked questions about the ley del mono

Do I need the building permit first?

No, and that is precisely the point of the simplified procedure: the permit and the approval are obtained in one step. Through the general route you would have to get the permit first and then apply for approval, with two separate processes and two payments.

My extension is from 2019. Can I use this route?

Not through this route. The law requires the construction or extension to predate 4 February 2016, and that date admits no exceptions. In that case, what applies is regularisation through the general route.

My house is worth more than 2,000 UF today. Am I excluded?

Not necessarily. The appraisal that counts is the one on the certificate from the Servicio de Impuestos Internos for the first half of 2016, not the current one. Many properties that exceed the cap today still qualify using the figure from that date, so the first step is to request that certificate.

A neighbour reported me. Can I still regularise?

As long as there is a pending complaint for breach of planning rules before the Municipal Building Department or the Local Police Court, this route is not available. The first step is to resolve that proceeding, and there it matters whether the infringement has become time barred.

Does it work for a barbecue area or a storage shed?

The law is designed for homes and their extensions, and it also covers small, harmless businesses and social facilities. An accessory building is assessed on whether it counts towards the home's built area or not, and that calculation is what determines which regime it falls under.

How do I prove the construction predates 2016?

With anything that has a date: photographs, receipts for materials, contracts with the builder, utility bills for the extended property, and above all historical satellite images, which tend to be the cleanest evidence because they show the building existing on a given date.

What happens if I never regularise?

The house stays standing and you carry on living there. What you cannot do is sell it well, mortgage it, insure what has not been declared, or pass it on without carrying the problem over to your heirs. In practice, the cost is not paid in fines: it is paid in the price, on the day you need to sell.

How we do it

We start by working out whether the case qualifies, which is a short review that determines everything else: the 2016 appraisal certificate to see which regime applies, the actual measured area, and whether there are pending complaints or the property is in a risk area. That tells us whether to proceed under law 20.898 or through the general route.

Next comes the file: the survey of what was actually built, the scale plans, the specifications and the professional's report. Our own team of surveyors and architects does the survey and the plans, so when the Municipal Building Department raises an observation it is corrected and resubmitted without coordinating between separate offices. If you want a sense of scale before talking to us, the regularisation cost calculator gives a reference figure.

When the problem lies earlier, we resolve it first: a title study if ownership is unclear, regularisation of title if the property is not registered, or the posesión efectiva, the Chilean grant of probate, if it comes from an estate that was never processed. Regularising the construction on a title that is not in order is starting with the roof.

Send us the property's roll number and a photo of what was built, and we will tell you which regime it falls under, what documents you will need, and whether it is worth speeding up the process before the deadline.