Influence of occupant behaviour on the energy performance of dwellings is an emerging research topic: Not only the amount of studies is insufficient, but also they provide contradictory results. The aim of this study is to reveal the sensitivity of dwelling energy performance to the presence of occupants in different dwelling types, assuming that presence is the precondition of behaviour. Sensitivity of dwelling energy performance to occupant presence is analysed using Monte Carlo method, which is one of the most commonly used methods to investigate the approximate distribution of possible results (energy performance) on the basis of probabilistic inputs (presence). For this study, the hourly inputs of presence are derived from a database of 319 dwellings in the Netherlands. 4 different types of Dutch reference dwellings are selected for the simulation model: Row house, Corner/Semi-detached, Free standing, and Flat. Steps of the methodology are as follows: (1) Pre-processing behaviour data (the maximum and minimum values of the input parameters); (2) Gathering samples from SimLab pre-processor; (3) Simulating each sample by a dynamic simulation program to collect output data. (The simulations are made with „one at a time? approach. Each input is perturbed in turn while keeping all other inputs constant at their nominal value); (4) Combination of inputs and outputs in post-processor of SimLab to run Monte-Carlo analyses. Results of this study showed that presence varies at the weekends more than it does during the weekdays. Corner/semi-detached dwelling is the dwelling type that presence is the most consistent during the weekdays, and row house at the weekend. Flat is the dwelling type that demands the least heating energy, and corner/semi-detached is the most. Weekdays are more influential on the heating energy demand than the weekends. Corner/semi-detached dwelling energy performance is the most sensitive to presence on weekdays, row house at the weekend.