NTC 4595:2025: what changed, and when it binds you

On 19 November 2025 the governing board of ICONTEC ratified a new edition of NTC 4595, the standard by which schools are planned and designed in Colombia. On the same day it ratified another document in the same series, and the Ministry of Education published both together on 2 December. There was no announcement.

It is worth starting with what almost nobody says, because it is the first thing a team needs to know before redoing anything: the areas per student did not move. A preschool classroom is still 2.00 m² per student and a primary or secondary classroom 1.65 m², exactly the figures of the previous edition. What changed is less visible and weighs more: the method by which the size of a school is worked out.

Not a law, and it can still cost you the contract

NTC 4595 is a Colombian technical standard, issued by ICONTEC, which is a private not-for-profit body and at the same time the national standards body. That double status is not a detail: it defines exactly how far the standard binds.

The standard is consistent with that. It contains no adoption clause, no transitional regime, no commencement date other than that of its ratification, and no declaration of mandatory force — this was checked by searching those words across all 137 pages. And in its Annex A it does the opposite: it says of its schedule-of-areas tables that they "are not for mandatory use".

So the useful question is not whether the standard binds, but who is imposing it on you. And there the answers are concrete:

For a private school, the operating licence does not name it either. What Decreto 1075 asks for in the education project proposal is the "specification of the standards or criteria adopted to define the conditions of the physical plant". In other words: you declare which standard you adopted. NTC 4595 comes in that way — but because you named it.

From when the 2025 edition applies

There is a drafting detail here with consequences. Resolución 1349 cites "NTC4595" with no edition year. An undated reference points, by convention, to the latest edition in force of the referenced document. Since there is no act governing the transition between editions, the reasonable reading is that from the publication of the 2025 edition it is that one which applies to anything submitted for funding.

So the only rule that will serve you at the table is this: read which edition is named by the document that imposes it on you. Tender documents that say "NTC 4595" on their own refer to the one in force; ones that say "NTC 4595 de 2020" tie you to the 2020 edition even though a later one exists. They are not the same obligation and they are not met with the same drawings. If no year is given, ask in writing and keep the reply.

What was ratified on 19 November 2025

It was not one standard: it was two documents, studied by the same technical committee — CTN 162 on the construction of school buildings — and ratified on the same day.

And there are three pieces, not two, because above them sits NTC 6705:2023, which sets the admissible minimums for a school infrastructure plan. All three are in force and they divide the work: NTC 6705 says what a plan has to meet, GTC 223 explains how to prepare one — and it succeeds GTC 223 of 2011, not NTC 6705 — and NTC 4595 governs the physical design of whatever comes out of it.

Which edition this is being compared against

NTC 4595 was first ratified in 1999 and is now in its fifth edition. Three matter today, because all three are in circulation:

This article compares the 2025 edition against the 2020 one, which is the edition it replaces. And it can be done because the 2020 edition is indeed published by the Ministry of Education, in the same directory as the others, even though the file name does not identify it and it is hard to find.

What did not change, and is worth looking at first

This is the part that saves money, because it stops you redoing what is already right. It was verified by opening both editions and comparing clause against clause:

• —Classroom areas, identical. Preschool 2.00 m² per student, primary and secondary 1.65 m², multigrade 1.80 m². Even the note survives that requires 3 m² to be added for the teacher’s station when a group falls below thirty students.
• —The 2.5 m² per student for circulation, pedestrian standing areas and green areas, with no less than 60% for green areas and 30% of those for continuous planting of native or adapted species.
• —The school garden: a minimum of 30 m² up to 500 students and 50 m² above that, with irrigation water provided for.
• —Heat island control: shade at least 50% of external hard landscaped areas, either with tree planting at ten years of growth or with paving of a solar reflectance index no lower than 28%.
• —The maximum gradient of 15% across the buildable area, and a site proportion between 1:1 and 1:4 as favourable.
• —The effective utilisation percentages for spaces: 80% of available time for type B, C and F spaces, 90% for A and D, 100% for E. In 2020 these ran in prose; in 2025 they are Table 5. Same content, better presented.
• —The whole safety chapter. Structures, means of escape, risk prevention, vandalism and maintenance were left as they were, including the classification of school residences in NSR Group III.

What did change

The table that gave the size of the site left the normative body

This is the big change and the one least reported. In the 2020 edition, Table 2, "Basic site indicators", sat in clause 4, which is normative, and worked as a catalogue: you looked up the row for your size of school — 1,440, 960, 480, 240, 90, 60 or 30 students — and read off the total site area and the square metres per student.

In the 2025 edition that table is Table A.1 of Annex A, which is informative, and the annex says of its tables, in as many words, that they "are not for mandatory use". In its place, the normative body carries Tables 3 and 4, which hold no values but a procedure. The standard describes them as "a simulator for building the programme platform" and recommends taking them into a spreadsheet.

And it took with it a rule that moves budget: the note requiring the site to be increased by at least 30% on slopes steeper than 15% was a note to the normative table of 2020, and today it is a note to a table the standard itself declares not mandatory. The requirement of a maximum 15% gradient does remain in the normative body; the additional site cost associated with the slope does not.

The playground stopped being what is left over

What is genuinely new is áreas libres curriculares — curricular open space — in clause 5.3.6.3 and Table 9. The expression does not appear once in the 2020 edition, where the matter was dealt with in a single paragraph saying that the activities of type F spaces could also take place in open areas.

Now it is a regime. Open space stops being calculated as a residue — whatever is left of the site once the blocks are placed — and starts being programmed as area with a teaching function, with two concrete requirements: that the open areas of type F spaces accommodate at least 50% of the school population at the same time, and that each kind of open area be sized by its own index per student.

Table 9 characterises those areas — the flag plaza (plaza de banderas), the forum classroom (aula-foro), group classrooms, collaborative work nooks, and sitting and reading areas — and gives each a use, an occupancy criterion and an index running from 0.7 to 1.65 m² per student, capped by the 2.5 m² per student of Table 2. And it expressly excludes what many people would count: sports courts, terracing, car parking and services are not curricular open space.

You can now go above four storeys

The 2020 edition stopped at four storeys, full stop. The 2025 one keeps that ceiling as the rule but opens an exception for "cases in which, by reason of urban conditions of shortage of institutional education land, the total height proposed exceeds 4 storeys". It is a change written for the urban school on a tight site, and it is not free: it requires meeting the occupancy and means-of-escape minimums of titles J and K of NSR-10 and of local planning rules, applying whichever is stricter; documentary backing with a certificate from the municipal planning office; and an evacuation and emergency response plan plus a risk management plan.

Eaves stopped counting as built area

Small in wording and very useful in practice. Clause 8.3.3 adds that roof overhangs, eaves, façade fins and other devices acting as bioclimatic control shall not count as built area towards the programme areas or towards the maximum percentage allowed for external circulation. It is the difference between being able to shade a façade and having to argue about it with whoever balances the schedule of areas.

A space is no longer necessarily a room

The root of all the above is in the definition in clause 3.1. In 2020, an ambiente — a teaching space — was "a place or set of closely linked places". In 2025 the definition accepts that school activity may take place physically, remotely or virtually, at the school or away from it, and that the space may be built and covered or open to the sky.

It is a definition written after the pandemic, and the standard’s introduction says so: one of its three purposes is to take in the changes in habitability left by covid-19 and to open the door to "unbuilt" teaching spaces. The new clause 4.3 runs along the same line, recognising the autonomy of indigenous peoples over their own education infrastructure, harmonised with basic conditions of safety and accessibility.

The PEC comes in alongside the PEI

Clause 5 used to be called "Institutional Education Project (PEI) and school spaces". It is now called "Institutional Education Project (PEI), Community Education Project (PEC) and school spaces", and the abbreviation PEC went from appearing three times in the whole 2020 edition to thirty times in the 2025 one. This is not cosmetic for anyone working with ethnic communities: the schedule of areas can be derived from the PEC, and that gives normative backing to a brief that looks nothing like an urban school’s.

The standard is tied to planning

The 2020 edition does not mention NTC 6705 once, because it did not exist. The 2025 one puts it into its scope — clause 1.1 — and takes whole definitions from it. And there is a change of scope there that goes unnoticed: in 2020, assessing and adapting existing facilities was a free-standing use of NTC 4595; in 2025 it is done "within the framework established by NTC 6705". To touch a school that already exists, the standard sends you to another standard first.

The practical effect is a separation of tasks that used to be muddled: planning — how many sites, where, with what enrolment, what is extended and what is replaced — belongs to the infrastructure plan; physical design belongs to NTC 4595. If your public body is putting a plan together, the order matters: the plan first, the design afterwards.

Services: two new clauses and one absence

• —Two entirely new clauses. 7.4 requires an early fire detection and alarm system, referring to NFPA 72; and 7.5 brings in heating, ventilation and air conditioning, backed by a bioclimatic and thermal comfort study.
• —7.3 was widened. It used to be "communications and alarm installations"; it is now "voice, data, intrusion, closed-circuit television (CCTV) and sound installations", with the structured cabling standards ANSI/TIA 568 and 569, absent in 2020.
• —Water and drainage moved from 7.4 to 7.6 and their heading now includes fire extinguishing.
• —The absence: the reference to the Colombian electrical code, NTC 2050, disappeared from the list of documents applicable to electrical installations. What remains is RETIE and RETILAP as in force "and the standards that complement them".
• —Clause 8 stopped being called "comodidad" and is now "confort". It is terminological and affects all four sub-clauses. If your tender documents cite "comodidad visual, numeral 8.2", they are citing the old edition.

Accessibility: it gains a lavatory and loses a ratio

What it gains is concrete and welcome. Clause 5.4.9 creates the universally accessible sanitary unit: it must sit outside the student toilet blocks, have a minimum of 5 m² per fitting set, and be suitable for menstrual hygiene and for people of diverse genders, which the previous edition did not contemplate. Double-loaded corridors rise to a minimum width of 2.10 m, and the first-responder area is quantified for the first time: a minimum of 9 m² covered with an accessible lavatory attached.

What it loses is concrete too. Clause 6.3.3.3 in 2020 required one accessible space for every ten parking spaces, two between eleven and fifty, and no more than 50 m from the main entrance. The 2025 one asks for "at least one reserved space […] or whatever the planning rules applicable in the territory establish", applying whichever is stricter, and the position near the entrance went from "shall" to "should".

The pattern: fewer figures of its own, more referrals

Lined up, the changes describe a consistent editorial decision. The standard let go of hard numbers it used to supply itself and handed them back to local planning rules or to each institution’s education project:

• —The size of the site: from a normative table to an informative annex.
• —Classroom occupancy: from "maximum number of students" to "occupancy reference", with the real capacity referred to the regional education authority.
• —Preschool outdoor area: 2020 required an area no smaller than half the classroom; 2025 extends the requirement of contact with the outside to all type A spaces, but with no figure of its own, referring instead to the curricular open space.
• —Car parking spaces: 2020 set one per five bicycle spaces, at 20 m²; 2025 refers to the instruments of territorial planning.
• —Accessible spaces: the ratio and the maximum distance to the entrance are gone.
• —Separation from petrol stations: the 60 m set by Table 1 in 2020 is no longer there.

If your project was designed to the previous edition

There is no transitional regime, so the answer comes not from the standard but from your contract. In this order:

1. 1Look at which edition is named by the document that imposes it on you. Tender documents, funding agreement or commencement record. If it names an edition with a year, that is your obligation even though a later one exists.
2. 2If it names no year, ask the public body in writing which one applies, and keep the reply. It is the kind of ambiguity that is cheap to resolve before submission and expensive afterwards.
3. 3Check first what did not change. If your brief meets the classroom indices, the 2.5 m² of open areas and the utilisation percentages, that work is done and is not redone.
4. 4Then look at the curricular open space. That is where a 2020 project falls short, because the concept did not exist. It is usually an exercise in characterising and qualifying the open space you already have, more than in adding area.
5. 5Go to the POT for the figures the standard let go of: parking, accessible spaces, plot ratios. And leave it documented in the design statement.
6. 6Do not redo the site layout on rumour. Before moving a block, demand the clause that requires it to be moved.

And if the project has not started yet, the order that avoids rework is the usual one: the schedule of areas is closed at concept design, not later. In public work, moreover, what is assessed is not only the project but how it is presented: that is the subject of how public architectural competitions work from the inside. And if what you need is not what changed but how the project is put together from scratch, that is in how a school is designed in Colombia.

What this article does not claim

For consistency with the rest of this blog, the gaps are declared rather than filled:

• —It is not claimed that an act exists adopting NTC 4595 with general effect. What was found and is cited is narrower: a resolution requiring it as a condition of funding, and an article of Decreto 1075 requiring it for state school residences. That no other was found does not prove none exists.
• —The exact date of Decreto 974 de 2026 was not verified, which added that paragraph, nor that of Resolución 13107 de 2024, which amended article 3 of Resolución 1349. The content of both is verified against compiled text.
• —It was not checked whether any regional education authority requires NTC 4595 by its own administrative act, for an operating licence or for works. The sweep covered national rules.
• —The ICONTEC catalogue could not be consulted, which is where the formal status — in force, annulled, replaced — of each document is recorded. What is asserted here about NTC 6705 and GTC 223 comes from the text of the standards themselves, which is a primary source but is not the catalogue.
• —No table from the standard is reproduced. Both editions are copyright documents of ICONTEC and state that reproduction is prohibited. Clauses are cited here, the content of each table is described and individual figures are given; to work with it you have to open the document.
• —Not every change is listed. Annex D of the 2025 edition runs to thirty-two pages. This article covers the ones that move the design or the budget, not the drafting ones.

Both editions and the guide can be downloaded free from the Ministry of Education website, and they are linked below. Before taking an expensive decision on a particular project, open them: it is half an hour, and it is what separates an assertion from a citation.