Timber frame and prefabricated

The difference lies in where the work is done. Differences in time and risk follow from that.

Solution	Where the structure is built	Consequence
Timber frame	largely on site, the frame is erected on the plot	more flexibility
Prefabricated	walls, roof and structure are made in a factory and brought to site for assembly	more decided in advance

The material is similar but the place of production differs, and that difference determines everything else. Intermediate solutions are common, for instance factory made wall panels with a frame built on site.

One figure explains a great deal. On commercial sources, factory produced walls, roof and structure make up 40 to 50 % of the whole budget.

Part	Share	When decided
Factory produced structure	40 to 50 %	before site work starts
Foundations, services, internal finishes, external works	the remainder	during construction

This means half the budget is decided before anything happens on site. The other half does not depend on the choice of technology to the same degree.

Practical consequence: a prefabricated supplier's quotation covers a large part of the budget but not the whole project, and this is often confused. A client who reads an element supplier's quotation as a project price underestimates the total cost by roughly half.

Three conditions must be met. The design must be complete before production starts. Changes cannot be made in the factory during production.

The plot must be accessible for transporting large elements and using a crane. Access is checked before the method is chosen.

The foundations must be complete and accurate, because elements are made to dimension. An error in the foundations stops the erection.

The third condition is the strictest. A dimensional error in the foundations, which would be correctable when building on site, becomes expensive with a prefabricated solution: an element does not adapt, it either fits or it does not.

On commercial sources, timber frame houses are completed in roughly 8 to 14 months. The actual period depends on the delivery schedule.

The time saving is not merely convenience. A shorter construction period means a shorter period of temporary accommodation and less exposure to price movement during the works, which given 2026 price movements is not a minor factor.

The saving does not begin on day one, however. Preparation for factory production takes time, and the design must be complete earlier. The length of the whole process may therefore be shorter or similar, depending on how complete the design was at the outset.

Three situations. Where the design is not complete and solutions are to be refined during construction.

Where the shape of the building is complex, which reduces the advantage of factory production, since repetition is where its saving comes from. Repetition is the main condition for factory production.

Where access to the plot is restricted, for instance in a tight urban setting. Transporting large elements then becomes expensive.

The first situation is the most common in Estonian house building, and it is the main reason a prefabricated solution does not work on some projects. The question is not one of technology but of whether the client is ready to decide in advance rather than during construction.

Timber frame and prefabricated differ in where the structure is built, and that determines the whole economic logic. The factory produced part is 40 to 50 % of the whole budget, which means half the budget is decided before site work starts. Construction time is 8 to 14 months, but the saving does not begin on day one, because preparation takes time.

Four rules: check design readiness before recommending a prefabricated solution. Explain to the client that half the budget is decided before site work starts. Check access and foundation accuracy in the early design stage. Do not promise a time saving without allowing for preparation time.