Nowadays, it is no longer enough to renovate a private house “by eye” – clearly defined legal, technical, and energy requirements must be met. Since 2025, with the update of technical regulations for construction, stricter controls on renovation have come into force: for design, energy efficiency class, and the document submission process. In this article, we will discuss what the Construction Law refers to as renovation, how it differs from simple repairs, and what specific requirements will apply in 2025.
What does house reconstruction mean according to the law?
According to Article 2(44) of the Construction Law, reconstruction is a type of construction where, without changing the purpose of the building, but changing its essential characteristics, construction work is carried out:
increasing or decreasing the volume of the building, changing its height, length, width, structure, engineering systems, or anything else that affects the technical characteristics of the building.
The most important thing is to distinguish between when the work is considered simple repair and when it is reconstruction. For example:
- if you are only replacing windows or roofing, this is simple repair work;
- if you are changing the roof structure, raising the roof ridge, installing an attic or an extension, this is reconstruction;
- if the layout is being changed and load-bearing walls are affected, this is also reconstruction;
- if the foundation structure is being changed or dug deeper than the existing boundaries, this is reconstruction.
Legislation in force in 2025 additionally stipulates that energy requirements apply to the entire volume being reconstructed, even if the work is only partial. This means that “cosmetic” solutions are no longer sufficient – all technical characteristics of the building must be assessed.
“Reconstruction is not a repair, but a structural change. If you change what held or protected the building, you need to coordinate and document it,” says Tomas Paulauskas, construction policy specialist at the Ministry of the Environment.
When is it mandatory to obtain a permit to reconstruct a house?
In 2025, reconstruction of a house without a building permit will be extremely limited and only in exceptional cases. Unlike simple repairs, reconstruction always involves fundamental changes to the structure, so in almost all cases a building permit is required and the process must be carried out through the Infostatyba system.
According to the laws in force, a permit is required when the reconstruction involves:
- changing the dimensions of the building (height, length, width, volume),
- adding new floors (e.g., attic or basement),
- changing the roof structure or angle of inclination,
- the load-bearing structures (beams, columns, foundations) are changed or reinforced,
- the engineering system is reorganized, connected to networks or routes are changed,
- the energy characteristics of the building are changed or the thermal insulation of the entire facade is reconstructed.
Permission is not required only when the reconstruction is carried out in a non-urbanized area, for a simple structure, when the load-bearing structures or the volume of the building are not changed. However, these conditions apply very rarely to individual residential houses.
“If you only change what you can see, it may still be considered renovation. But if you change something that affects the stability or volume of the building, it is considered reconstruction, which is considered unauthorized construction without a permit,” says Rūta Valaitytė, head of the VTPSI control department.
What does the VTPSI check?
In the case of reconstruction, the State Territorial Planning and Construction Inspectorate checks:
- whether the submitted project complies with the type of construction (reconstruction vs. new construction),
- whether the permit was issued legally and whether the construction complies with the project design,
- whether all STR requirements were complied with during the reconstruction (e.g., distances from the plot boundaries, structural strength, energy efficiency standards).
If no permit is submitted or work is carried out without a project, the VTPSI may suspend the work, impose a fine, or require the building to be restored to its original condition.
Energy efficiency requirements for reconstructed houses
From 2025, individual residential houses undergoing reconstruction will be subject to clear energy efficiency requirements, which must be met even if only part of the building is being renovated. State policy in this area is becoming increasingly stringent: the aim is to ensure that renovated buildings are economical, energy-efficient, and meet at least the minimum efficiency threshold.
According to information from the Ministry of the Environment, when renovating a house, it is necessary to ensure that:
- an energy efficiency class of at least B is achieved if more than 25% of the external envelope is renovated;
- insulated structures comply with modern thermal resistance requirements, i.e., walls, roofs, and floors must meet at least the minimum requirements for new buildings;
- windows and doors would be replaced with ones with a heat transfer coefficient that complies with the relevant STR requirements (usually no more than 0.85 W/m²·K);
- the building is airtight and, if the entire volume is being renovated, an airtightness test (blower door) is performed to confirm compliance with the class.
It is important to note that energy efficiency requirements apply to the entire reconstruction project – if an extension is added or the roof is raised, the entire section must comply with the class requirements, regardless of whether other parts of the building remain untouched.
“Every renovation is an opportunity to improve the efficiency of a house. The state supports real energy savings, not cosmetic repairs,” says Lina Juozaitienė, Head of the Housing Policy Division at the Ministry of the Environment.
In addition to energy efficiency, when designing and implementing renovations, it is necessary to ensure that insulation materials, component solutions, and sealing methods comply with modern standards. Improperly designed or executed insulation renovation may prevent a building from achieving the required class, which may become an obstacle to obtaining construction completion documents or support.
Which parts of the building are subject to technical renovation requirements?
When renovating a detached house in 2025, many structural solutions will be subject to stricter supervision and assessment. This means that even seemingly simple work, such as raising the roof or adding an extension, may require a full project design and compliance with STR regulations.
Changes to the facade and volume
Any external change that alters the dimensions of a building – whether it be a change in height, length, width, or volume – is considered a reconstruction and is subject to all relevant requirements. When changing the facade, it is necessary to ensure that compliance with architectural regulations is maintained (if the area is located in a protected zone) and that the insulation layer meets the required thermal resistance. Even if the external wall is increased due to additional insulation, this must be justified in the project.
Roof replacement or reconstruction
Replacing the roof covering may in itself be considered simple repair work. However, if the roof pitch or height is changed, an attic or terrace is added, or the structural layout is changed, this is considered reconstruction. In this case, it is necessary to prepare a project, obtain a permit, and ensure that the new solutions comply with energy efficiency and structural safety requirements.
Redesign of load-bearing structures
One of the most important aspects of reconstruction is whether load-bearing structures are affected. Changing or reinforcing foundations, dismantling or redesigning load-bearing walls, installing additional floors or columns – all this falls within the scope of reconstruction. Such decisions require a technical design of the building, which must be prepared by a certified designer.
If the work affects the mechanical stability of the building, an additional building inspection may be required, especially if the design is prepared after partial demolition or the start of construction.
When is a technical design necessary?
The practice for 2025 is clear: if the volume, structure, or energy characteristics of a building are changed, a technical design is required. A simplified design is only applicable when the reconstruction is minimal, the main parameters of the building are not changed, and this is confirmed by responsible specialists.
“A technical design is not a bureaucratic luxury – it protects the builder from legal, financial, and structural errors,” says Vilius Jakutis, a certified structural engineer.
Project coordination and submission of documents for reconstruction
Even simple house reconstruction requires not only technical preparation but also legal coordination. From 2025, all building permits, including for reconstruction, will only be issued through the Infostatyba digital system, which means that the entire process, from project submission to decision-making, will be carried out electronically.
When is it necessary to submit a project through Infostatyba?
A project is mandatory in all cases where the volume, facade, structural system, or energy class of a building is changed during reconstruction. If the builder plans to carry out reconstruction according to an individual project, it must be prepared by certified specialists and uploaded to the Infostatyba system, where it is reviewed, coordinated, and approved.
This system is also used to coordinate solutions for connection to engineering networks, fire safety solutions and, in certain cases, design conditions. All coordination is carried out within the institutions, but the builder and designer are responsible for the quality of the project.
When is an expert opinion required?
If the structural solutions of the building are non-standard, the planned works affect load-bearing structures, or the object is located in a cultural heritage or special protection zone, an expert assessment of the project may be required. This is carried out by an independent certified expert who assesses whether the construction solutions comply with technical requirements, norms, and safety standards.
Expertise is also necessary if the project was prepared independently, without a qualified architect, but it later became apparent that a building permit was required. In such a case, the municipality may require an additional expert opinion on the suitability of the project.
What documents are required?
When renovating a residential building, the following main documents must be submitted via Infostatyba:
- technical design of the building in PDF format,
- summary of design conditions (if issued),
- topographical photograph and site plan,
- architectural and structural parts,
- engineering system solutions,
- builder’s authorisation, if acting through a representative.
“If you are planning to rebuild the roof, extend the volume or build an extension, the project must be fully developed, approved and uploaded to Infostatyba. Otherwise, there will be legal consequences,” says Gintaras Strelčiūnas, head of the municipality’s architecture and urban planning department.
Need help?
Reconstructing a house in 2025 is not just a physical renovation, but also a responsibility for the legal and technical soundness of the project. With increasingly stringent energy efficiency, design, and coordination requirements, even minor errors can lead to construction being halted or additional costs.
If you are unsure whether your planned work falls within the definition of renovation, whether you need a permit, or whether your project complies with the applicable STR requirements, the stav.lt team can help.
What we can offer:
- detailed consultations on renovation requirements in 2025;
- project evaluation and preparation for submission via Infostatyba;
- assistance in obtaining permits, expert opinions, or energy certification;
- search for solutions in cases where reconstruction has begun without a permit.
We work with professional architects, designers, and engineers, so we can help you both in preparing a project from scratch and in taking it over for corrections or completion.