A new daylight evaluation tool using a simplified assessment method to determine the daylight quantity provided to a typical room was developed. Its calculation method is based on a set of formulas integrating the main factors characterizing the indoor space and the outdoor context. The results are expressed as a corrected Glass-to-Floor ratio (GFR) which is used as a proxy for the daylight provision. This value can then be used to attribute a rating or 'Daylight score' to each space. The main finding is that the simplified method is an easy and relatively reliable estimation for daylight provision. A comparison of the tool with detailed daylight simulations according to the daylight factor method of EN 17037:2018 shows that a high correlation is obtained. The tool is applicable for any case which has conditions matching closely to the models and situations defined. Due to its easy implementation and the limited number of input parameters this evaluation method could be well suited for building passport schemes.