Short answer: under Estonian law, a winter garden built onto a private house is an extension of the house. If the winter garden increases the volume of the house by up to 33%, a building notice and a building design are enough — no building permit is needed. An extension of more than 33% requires a building permit. What matters is not the floor area of the winter garden but the percentage it adds to the volume of the house.
The common belief that “a winter garden over 20 m² needs a building permit” applies to a free-standing building, not to a winter garden attached to a house.
Is a winter garden an extension or a separate building?
The Estonian Building Code defines an extension as construction that changes an existing structure by building onto, on top of or under it (Building Code § 4(2)). A winter garden built against the wall of a house is therefore an extension of the house.
A free-standing winter garden (for example a garden pavilion) is a separate building, and floor-area limits apply to it.
Winter garden attached to a private house: the 33% rule
Annex 1 of the Building Code sets out the following for private houses (register codes 11100 and 11210):
| House | Extension up to 33% | Extension over 33% |
|---|---|---|
| Typical private house: footprint over 60 m² or house over 5 m high | Building notice and building design | Building permit |
| Small house: footprint 20–60 m² and up to 5 m high | Building notice | Building notice and building design |
The 33% is calculated by volume — the law refers to an extension “by more than 33 per cent of its originally planned volume” (Building Code § 26(2)).
After construction, a notice of use is submitted for the extension of a private house; a use permit is not required (Building Code Annex 2).
Note: the rules are stricter for apartment buildings and non-residential buildings. If the footprint of the building exceeds 60 m², even an extension of up to 33% requires a building permit. This article covers private houses.
Calculation example
Take a typical private house and a winter garden built onto it:
| Floor area | Height | Volume | |
|---|---|---|---|
| House | footprint 150 m² | average ~6.5 m (including the roof space) | 975 m³ (from the construction register) |
| Winter garden | 4 m × 7 m = 28 m² | average 3.2 m (3.6 m at the wall, 2.8 m at the outer edge) | 28 × 3.2 = 89.6 m³ |
| Extension | 89.6 / 975 = 9.2% |
9.2% is well below the 33% limit — a building notice and a building design are enough.
How large a winter garden would still fit? 33% of the house volume is 975 × 0.33 ≈ 322 m³. With the same average height of 3.2 m, that is about 100 m² — a typical winter garden is far below that.
To calculate the volume of the winter garden, multiply the floor area by the average height. With a sloping roof, the average height is the mean of the height at the wall and at the outer edge. You can find the volume of your house in the Estonian Register of Construction Works (ehr.ee) under the building data.
Free-standing winter garden: the 20 m² and 60 m² limits
If the winter garden is not attached to the house, it is a separate building (Annex 1, ancillary building of a private house):
| Footprint and height of the winter garden | What you need |
|---|---|
| Up to 20 m² and up to 5 m high | No notice or permit required |
| 20–60 m² and up to 5 m high | Building notice and building design |
| Over 60 m² or over 5 m high | Building permit |
Even where no notice or permit is required, the building must meet construction requirements and the local plan.
Legalising a winter garden step by step
- House data from the construction register. Check that the house is recorded correctly (volume, footprint, earlier extensions). If earlier buildings have not been legalised, this must be done first — it will delay the schedule.
- Original drawings. If the house has DWG drawings or drawings in good condition, they can be used and the design is faster and cheaper.
- Topographic survey (geodetic base plan). The building design is prepared on a geodetic base plan. If one has not been made for the house before, it must be ordered — allow 2–3 weeks. Whether an existing survey can be used depends on its age and the requirements of the municipality. Since 1 January 2018 Estonia has used a new height system (EH2000), so a survey made before then cannot be used as the basis for a new design. We will review your documents and tell you whether a new survey is needed.
- Building design. The design is prepared by a qualified designer.
- Building notice in the construction register. The notice is submitted together with the design via the construction register. During the procedure the municipality may ask for corrections or photos.
- Construction and construction log. A construction log is kept for the works.
- Notice of use. After completion a notice of use is submitted and the winter garden is registered as part of the house.
How much does legalisation cost and how long does it take?
Approximately €500–1,800, depending on which documents already exist:
- DWG drawings or drawings in good condition available: building design including register entry and legalisation approximately ~€500
- No topographic survey: add approximately ~€650 and 2–3 weeks
- Nothing available: essentially a full design, depending on the situation up to ~€1,800
Every house is different — we can give you an exact price and schedule once we have reviewed your house data. For the price of the winter garden itself, see winter garden prices. Feel free to send us details of your house and the winter garden you have in mind — we will guide you through the whole process.
FAQ: winter garden construction and permits
Do you need a building permit for a winter garden?
Usually not for a winter garden attached to a private house. If it increases the volume of the house by up to 33%, a building notice and a building design are enough. A building permit is needed for an extension of more than 33%.
Does the 20 m² limit apply to a winter garden attached to a house?
No. The 20 m² limit applies to free-standing buildings. For a winter garden attached to a house, the deciding factor is 33% of the house volume.
How do you calculate the percentage by which a winter garden extends the house?
Divide the volume of the winter garden (floor area × average height) by the volume of the house. You can find the house volume in the construction register. For example, a 28 m² winter garden with an average height of 3.2 m is 89.6 m³; for a 975 m³ house that is 9.2%.
Do you need a topographic survey for a winter garden?
A geodetic base plan is required for the building design. If one has not been made for the house before, it must be ordered (approximately ~€650, 2–3 weeks). Whether an existing survey can be used depends on its age and the requirements of the municipality. Since 1 January 2018 Estonia has used a new height system (EH2000), so a survey made before then cannot be used as the basis for a new design.
Do you need a use permit after construction?
Not for the extension of a private house — a notice of use is enough.
Does the same rule apply to a winter garden on the balcony or terrace of an apartment building?
No. The rules are stricter for apartment buildings and the consent of the apartment association is also required — see our overview of balcony glazing and apartment association consent.
Sources
- Estonian Building Code, consolidated text (in force from 01.10.2026) — Riigi Teataja: § 4(2) (definition of extension), § 26(2) (33% of volume)
- Building Code Annex 1 — table of building notice, building design and building permit requirements
- Building Code Annex 2 — table of notice of use and use permit requirements
- Requirements for building designs (Regulation No. 97 of the Minister of Economic Affairs and Infrastructure) — Riigi Teataja: § 15(2) (site plan tied to the geodetic system)
- European height system EH2000, in use since 01.01.2018 — maaamet.ee
Read also: winter gardens · uninsulated winter garden · can you use a winter garden in winter?
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