Owner-executed (self-build) construction
Building for yourself without a contractor. Act 25/2025 allows it for simple structures, family houses included, if a qualified supervisor leads the works.
What does owner-executed construction mean under Act 25/2025?
Owner-executed construction, in Slovak svojpomocná výstavba, means the builder has the building made for themselves instead of hiring an authorised contractor. How much of the work you do with your own hands is secondary. What defines the method is that no firm stands on site answering for the whole building.
Under Act 25/2025 Z. z., the default rule in § 26(2) is that the builder must have the building made by an authorised contractor, unless the builder is authorised themselves or the act says otherwise. Self-build is one of the cases where the act says otherwise, and it is not limited to garden sheds.
Can you self-build a family house in Slovakia?
Yes. Under § 26(3), a builder may self-build a simple structure (jednoduchá stavba) for themselves, provided the works are led by a person authorised for construction supervision. Under § 2(6)(a), simple structures include residential buildings with at most three dwellings, a built-up area not over 300 m2 and at most two above-ground storeys, optionally with one basement and an attic or set-back storey. A typical detached family house fits that description.
Reserved structures (vyhradené stavby) are a different category. They are not simple structures, and this route does not cover them. A project that falls outside the simple-structure definition goes back to the default rule and needs an authorised contractor.
Who has to lead the works?
The requirement depends on the type of work. For a simple structure the lead must be a person authorised for construction supervision. For lighter work the act accepts a professional lead with a lower qualification.
| Type of work | Who must lead it |
|---|---|
| Simple structure, including a family house within the definition above | A person authorised for construction supervision, for the whole duration of the works |
| Notified minor structure (see minor structure notification) | A person with professional qualifications: at least complete secondary technical education in construction, mechanical or electrical engineering plus three years of practice, or a relevant university degree. If you meet this yourself, you may lead it yourself |
| Building alteration | Same professional lead as for minor structures |
| Maintenance | Same professional lead as for minor structures |
| Reserved structure | Outside self-build; an authorised contractor is required |
The same rules apply to changes to a completed building and to demolition, so a self-managed renovation is covered by the same logic.
What must a self-builder do during the build?
Under § 26(4), the self-builder coordinates the works, contracts each supplier of work, machinery and materials individually, and is fully responsible for the obligations under the act. Under § 30(6) this becomes a concrete list of duties:
- keep a person authorised for construction supervision for the entire period of the works, and follow their instructions;
- use only workers who meet the qualification requirements of the act;
- secure the setting-out so the building sits where the verified project says it should;
- build in only construction products suitable for the intended use, installed as the manufacturer prescribes;
- keep the site equipment and operation compliant with the act and related rules;
- keep the project documentation, the building intent decision and the construction diary on site, and record significant events and progress in the diary;
- stop work immediately and protect the site when the supervisor or the state building inspection orders it.
Building without such a supervisor is an offence under § 79(2)(b). A supervisor is therefore a legal condition of self-build, not an optional extra.
What does the owner take on compared with a general contractor?
Self-build can save money, but it saves it only on the work you do yourself and on the coordination margin a firm would charge. What it mainly does is move risk. The comparison below is qualitative on purpose, because the real balance depends on the trades, the pace and the number of mistakes.
| Aspect | Owner-executed | With a general contractor |
|---|---|---|
| Coordination of trades | Owner plans the sequence, orders and waiting times | Contractor coordinates its own crews and subcontractors |
| Contracts | Many separate contracts, one per supplier | One contract for work covering the whole scope |
| Legal obligations | Owner is fully responsible under the act | Shared with the contractor according to the contract |
| Defects | Own work has no warranty; owner pays to correct it | Contractor remedies defects within the warranty period |
| Owner's time | Weekends, leave and a longer build | Mostly decisions and acceptance checks |
| Materials | Retail purchasing without a firm's trade terms | Contractor buys through its own supply channels |
Which trades can owners realistically do themselves?
A useful test is whether a mistake can still be found and fixed before the next layer covers it, and whether someone else has to certify or warrant the result. By that test, demolition of non-structural parts, interior finishing, insulation of attics and floors, masonry from block systems under supervision, and landscaping are realistic. Foundations, reinforced concrete, roof framing, waterproofing, electrical and gas installations and chimneys are better left to firms. Work for which the law requires special qualification or certification may only be done by people who hold it.
Warranty is the quiet cost. A firm that builds under a contract answers for its work. When you build it yourself, nobody does, and a leaking roof or a cracked slab found years later is your problem. Coordination is the other trap: a bricklayer who cannot start because the delivery came late costs you weeks, and a firm that is booked elsewhere will not wait for you.
How should you decide?
Treat self-build as a decision about which risks you want to hold, not only about price. Many owners get the best result by hiring firms for the structure and the hidden systems and keeping the visible, forgiving work for themselves. Agree the supervisor early, because that person decides what is acceptable on your site. The Building Act allows self-build of a family house, and it asks you to carry the responsibility that comes with it.
Frequently asked questions
- Do I need a supervisor if I build my own house?
- Yes. For a simple structure, which includes a typical family house, the works must be led by a person authorised for construction supervision for the whole build. Building for yourself without one is an offence. You must also follow that person's instructions.
- Can I lead the works myself?
- Only for lighter work. For notified minor structures, alterations and maintenance, the act accepts professional lead by someone with the required technical education and practice, which may be the owner. For a simple structure such as a house, the lead must hold the construction supervision authorisation.
- Who is responsible if something goes wrong on my site?
- You are. The self-builder coordinates the works, contracts suppliers individually and is fully responsible for the obligations under the act. There is no contractor to take over that responsibility, and work you do yourself carries no warranty from anyone.
- Can I self-build any building?
- No. The route covers simple structures, notified minor structures, alterations and maintenance. Reserved structures are not simple structures and require an authorised contractor. If your project falls outside the simple-structure definition, ask the building authority before you plan a self-build.
- Is self-build always cheaper?
- Not necessarily. You save on the labour you do yourself and the coordination margin, but you carry delays, purchasing mistakes, rework and the loss of warranty. The saving depends on which trades you do and how well you coordinate.