Timber beams are oftentimes used as joists in timber floors. Especially for small timber buildings like two story housing for single or few families, it may be necessary to let service pipes pass through the joists to avoid a reduction of the story height. Therefore, there is a need to have large holes in the timber joists, which under the current local guidelines and the future European regulations, leads to the use of timber beams of significant height. In this study, the capacity of glued-laminated timber beams with large round holes is evaluated. The paper presents results from novel experiments performed on beams with round holes positioned in two different configurations. The holes are considered as large, i.e. the diameter of the holes is 50% of the timber beam height or larger.The objectives are, in addition to the experimental investigations, to establish an umerical simulation approach of these experiments which can be used to future studies of possible solutions to the challenge of large holes in timber joists. For comparison, an analytical evaluation of the beams capacity in accordance with the future European regulations is added.