Helsinki caps plot coverage, requires bird-safe builds

Helsinki's new building regulations cap plot coverage and require bird-safe construction

Helsinki's new building regulations took effect on 5 November 2026, capping built coverage on detached and semi-detached house plots at 35% unless the local plan says otherwise and making bird-safe construction a requirement.

5 November 2026 by Robert Eduard Antal, facts checked automatically against the source · updated 6 November 2026

Key facts

The new building regulations apply to all matters initiated on or after 5 November 2026.

Buildings, constructions and terraces on detached and semi-detached house plots may cover no more than 35% of the plot, unless the local detailed plan says otherwise.

Bird-safe construction is a new provision intended to reduce the number of birds hitting building walls and windows.

Helsinki’s new building regulations took effect on 5 November 2026 and apply to all matters initiated on or after that date. They cap how much of a detached or semi-detached house plot can be built over and add bird-safe construction as a new provision, giving nature and stormwater management more weight in everyday building decisions.

What changes on plots

Buildings, constructions and terraces on plots for detached and semi-detached houses may cover no more than 35% of the plot area, unless the local detailed plan defines otherwise. The cap is meant to secure enough green space on plots, with managing urban run-off water and the comfort of detached house areas as the main objectives.

Bird-safe construction is a new provision intended to reduce the number of birds that hit building walls and windows. The Finnish regulation text requires the size, placement, surface patterning, glass properties and lighting of windows and other glass surfaces, such as glass railings, to be designed so that collision risk is minimised.

Other nature provisions in the text include:

if trees must be felled during the bird nesting season (1 April–31 July) for construction or demolition, they must first be checked with the help of a bird expert;
permit-requiring outbuildings on detached and semi-detached house plots must have a green roof unless solar panels or collectors are placed on it;
new or additional buildings on plots whose detailed plan has been in force for over 13 years need a survey of the plot’s natural and cultural-historical values.

Permits, reuse and emergency access

The revised Building Act has reduced municipalities’ ability to steer construction that needs no permit, so some earlier provisions were removed. Most fences, terraces and other ordinary garden constructions remain possible without a building permit.

The regulations encourage durable, adaptable and easily repairable buildings and the reuse of building materials. When a building is demolished, usable building parts must be removed for reuse if this is technically possible and does not cause unreasonable costs.

For new residential buildings, emergency access is primarily to be arranged on the plot or in the building itself, and rescue lifting places will no longer be located on public areas in new projects. This frees street and park space for planting, parking, snow management and public transport infrastructure.

Background

The update aligns the regulations with the revised Building Act and the Helsinki city strategy 2025–2029. Circular economy in construction is one of five fields where Helsinki plans special growth investments during the strategy period, and the city’s circular economy cluster includes some 200 companies or other operators. The city advises getting to know the regulations already at the planning stage of a project.

Drafted with AI assistance from the cited source. Every fact was matched automatically against the source text; it was published without an editor reading it. Tell us about any mistake and we correct it on the page.