How to choose a bunker or shelter: a checklist

10 questions to ask yourself before ordering a shelter or bunker

The right choice depends not on which bunker is the “strongest”, but on how many people need to take cover, where, and how quickly. Before you ask for a quote, answer ten questions. Your answers will save time for both you and the designer.

1. How many people must it hold?

   For institutions, the starting point is the maximum number of people in the building at any one time. For new public buildings, a shelter is designed for at least 60% of that number, and municipalities assess capacity on the basis of 1.5 m² of floor area per person. Do not forget staff, visitors and groups of children.

2. How quickly can people reach the shelter?

   During an air-raid alert, speed matters most. For a school or kindergarten, the shelter must be as close to the building as possible, and several small modules in different parts of the grounds sometimes work better than one large one.

3. Above ground or underground?

   • Above ground – faster installation, no deep excavation needed, easier to make accessible to people with reduced mobility.
   • Underground – the layer of soil provides extra protection and the structure is less visible, but excavation is required and the groundwater level must be assessed.

4. What are the site conditions?

   Assess the groundwater level, soil type, underground utilities, and access for a crane and heavy machinery. The regulation also requires the collapse zone of surrounding buildings to be assessed: it equals one third of the building’s height (para. 171).

5. What level of protection do you need?

   Is short-term protection for a few hours enough, or are you planning for a longer stay? From 2027, shelters will be classified into three levels: level 1 – up to 72 hours, level 2 – up to 24 hours, level 3 – up to 5 hours. This determines what ventilation, heating, water supply and toilets will be needed.

6. Does STR 2.07.02:2024 apply to the structure?

   If a shelter is mandatory under STR 2.07.02:2024 (Lithuanian construction technical regulation on the design and installation of shelters) or you expect state funding, the structure must be built from the materials specified in the regulation – cast-in-situ or precast reinforced concrete, or masonry. For private use, the choice is wider.

7. How will the shelter be used in peacetime?

   The law allows a shelter to be used for another purpose day to day, provided this does not prevent it from being made ready within the set time. It could be a storeroom, a workshop or a place to store equipment. Plan in advance so that the contents can be cleared out quickly.

8. Will it need to be relocated?

   For leased premises, a temporary construction site or a growing business, it matters that the structure can be dismantled and moved. Prefabricated structures have a clear advantage here.

9. What are the lead times?

   A solution delivered ready-made from the factory is the fastest to install. A custom-designed structure needs more time for design, approvals and installation.

10. Is a building permit required?

    This is one of the most frequently asked questions. The answer depends on the category of the structure and its location:

    • Under the construction technical regulation STR 1.01.03:2017 “Statinių ir patalpų klasifikavimas” (Classification of buildings and premises), a shelter (priedanga) and a blast shelter (slėptuvė) are classed as special-purpose buildings, an underground store (shelter) as an auxiliary farm building, and a fort, bunker and shelter as belonging to the group of other auxiliary buildings. A bunker is also listed among engineering structures.
    • Simple non-residential buildings include Group I buildings up to 5 m high and 50 m² in area, and Group II buildings up to 8.5 m high and 80 m² in area.
    • For non-special and special structures, a building permit is always mandatory. For simple structures it is not required unless the plot lies within certain areas: for Group II – a city or town, protected areas, the territories and protection zones of cultural heritage sites, gas transmission pipeline zones, etc.

    This means that a larger shelter on an institution’s grounds in a town will most likely need a permit, while a small structure on a private plot outside a town may not. The thresholds for structure categories and the list of areas where a permit is needed even for simple structures are set by legislation and may change. For this reason, the need for a permit for a specific site is always assessed by the designer under the current versions of the legislation; if necessary, you can also consult the State Territorial Planning and Construction Inspectorate.