Legalizing Unauthorized Buildings —
The Special Act Guide

Why This Act Matters

An illegally extended rooftop, a warehouse built without notification, a house missing from the ledger. Under normal circumstances, there is no way to legalize such unauthorized buildings. Once detected, enforcement penalties are imposed repeatedly every year until the violation is corrected, and restrictions arise on sales and loans as well.

The Special Act on the Consolidation of Specific Buildings is a law that temporarily legalizes such structures. It was enacted in 1981, 2000, 2006, and 2014, and a new Special Act is being pursued for enactment in 2026. Because the opportunity disappears once the effective period passes, it is important to review eligibility in advance.

Is Your Building Eligible?

The following is an eligibility flow based on common standards from past Special Acts. Since final criteria are confirmed upon promulgation, the below serves as a preliminary reference.

Procedure and Requirements

Legalization does not end with a mere notification. An architect surveys the current condition and prepares drawings for the application, which then passes through the local government's field inspection and building committee review before use approval is granted. If structural safety or evacuation standards raise issues during review, remedial construction may be required.

The key is timing. Due to the nature of a temporary statute, processing periods lengthen during the early period of enactment when applications concentrate. Completing the current-condition survey and eligibility review before the effective date allows you to apply the moment intake opens.

A Case From Practice

Our detached house project in Sangha-dong, Giheung-gu, Yongin began precisely with a legalization review of an illegal extension. The review found that the existing building coverage ratio was already at its limit, leaving no room for re-extension even after demolishing the illegal portion. We shifted strategy toward an extension permit using growth management plan incentives and completed it lawfully. Since unauthorized building issues have different solutions case by case, it is safer to review currently available paths together rather than simply waiting for the Special Act. View this project →

Frequently Asked Questions

Q. What is building legalization?

It is a system that temporarily legalizes buildings constructed without a permit or extended without authorization. Once complete, the building is registered on the ledger and enforcement penalties cease.

Q. Are all unauthorized buildings eligible?

No. Typically residential buildings below a certain floor area, completed before the effective date, satisfying structural safety and passing committee review.

Q. What can I do in advance now?

Preliminary eligibility screening and current-condition surveying. Preparing before the early intake surge is advantageous. In Yongin, LEA Architects conducts preliminary reviews. Contact us →