Sauna, garage, shed or garden house – the most common question is whether you need any paperwork for it at all. The answer depends on two things: area and height. And between the two there are a few limits worth knowing before the foundation is poured.
Quick table: detached house and two-apartment house properties
This table applies to detached houses (11100) and two-apartment houses (11210) and their ancillary buildings. Apartment buildings and non-residential buildings have stricter rules – see below.
| Building size | New construction | Extension up to 33% | Extension over 33% |
|---|---|---|---|
| 0–20 m², up to 5 m high | no documents needed | no documents needed | no documents needed |
| 20–60 m², up to 5 m high | Building notice + building design | Building notice | Building notice + building design |
| 0–60 m², over 5 m high | Building permit | Building notice + building design | Building permit |
| over 60 m² | Building permit | Building notice + building design | Building permit |
For apartment buildings, terraced houses and non-residential buildings the 20–60 m² range is stricter: there, even rebuilding a building service system needs a building notice together with a building design. And from 1 August 2026, rebuilding an apartment building or non-residential building of over 60 m², even by up to 33%, needs a building permit rather than a building notice.
Real-life examples
| Plan | Typical outcome on a detached house property |
|---|---|
| 12 m² garden house, 3.5 m high | No documents needed |
| 19.5 m² sauna, 4.2 m high | No documents needed |
| 24 m² garage, 4.5 m high | Building notice + building design |
| 45 m² sauna and guest house, 4.8 m high | Building notice + building design |
| 45 m² two-storey workshop, 6.5 m high | Building permit |
| 70 m² garage and workshop | Building permit |
Note the fourth and fifth rows. Both are 45 m², but the outcome differs – because one is 4.8 and the other 6.5 metres high. Height matters as much as area, and this is where people trip up most often.
How to measure so there are no surprises later
- Area means the building footprint area – the ground the building covers, including wall thickness. Not the floor area inside the room.
- Height is measured from ground level to the highest point of the roof. On a pitched roof that is the ridge, not the eaves.
- A terrace or canopy may count towards the area if it is structurally part of the building. If in doubt, ask the municipality.
- Don't plan right at the limit. 19.8 m² and 4.95 m is risky – a small inaccuracy during construction takes you over the limit, and then the building is finished and the documents are missing.
"No documents needed" does not mean "no rules"
This is the most common misunderstanding. Even if you don't have to submit a building notice, the following still apply:
- Fire safety requirements. A distance of less than 8 metres between buildings requires a fire separation solution. The neighbour's consent does not replace this requirement.
- The local authority's building regulations. Distances from the boundary, plot coverage ratio, number of buildings allowed on the property.
- The detailed spatial plan, if one applies to the property – building zone, height limit, architectural conditions.
- Restrictions: building exclusion zones along shores or roads, protection zones, heritage protection.
- Neighbours' rights. A building that blocks your neighbour's light or drains water into their yard is a problem even without any paperwork.
Practical tip: even if no documents are needed, it is still worth entering the building in the Building Register. It costs nothing and makes a later sale, mortgage and insurance easier.
Terrace, pool, borehole well and other structures
Structures have their own table, and the limits there are quite different:
- A terrace more than 1 metre above ground – building notice.
- A pool over 20 m² – building notice.
- A flagpole over 10 metres – building notice.
- A borehole well (abstraction under 10 m³ per day) – building notice together with a building design.
- A private sewage treatment plant – depends on capacity; larger ones need a building permit.
The requirements for structures are detailed and change over time. Check the row for your structure in the Building Register's Building Guide (Ehitusgiid) – it gives an answer for your situation.
If the building is already built
Then it is a different topic and a different procedure. In short: if the building was built before 22 July 1995, from 1 August 2026 it is considered lawful and you mainly need to prove when it was built. For a building built later without a permit, the procedure is carried out retrospectively. The full guide to legalising goes through the situations one by one.
Common mistakes
- 1.Looking only at the area. A height over 5 metres puts even a small building under the building permit requirement.
- 2.Planning right at the limit. 20.3 m² is already a different category.
- 3.Forgetting existing buildings. If the property already has ancillary buildings, the plot coverage ratio may be used up.
- 4.Assuming "without documents" means "without rules". Fire safety and neighbours' rights always apply.
- 5.Not entering the building in the register. A free step that saves a lot of trouble when selling later.
- 6.Starting to build before 10 days have passed. With a building notice, you have to wait out this period.
Back to all guides, or see the ready-made document kits and personal services.