The Defence Materiel Organisation (DMO) of the Netherlands Ministry of Defence identified that detailing warship layouts to space level of detail during the concept definition design phase is a complex and time consuming process. Currently it can take up to 150 man hours to complete a feasible general arrangement plan (GAP). Yet, these GAPs are crucial for balancing requirements and budget with technical feasible designs. Insufficient consideration of spatial details during concept definition increases the probability that sizing and integration issues will emerge later in the design process. This paper discusses the first steps undertaken to integrate a new layout generation tool, called WARGEAR (WARship GEneral ARrangement), into the DMO ship design process. WARGEAR is able to semi-automatically generate feasible and balanced detailed layouts in a matter of minutes, thus providing almost real-time feedback and design insight to naval architects. In this paper the issues of tool validation and user acceptance are addressed via a realistic warship design test case and a presentation of the test case results to a larger group of naval architects and senior management at the DMO respectively. The test case showed that WARGEAR is able to generate detailed layouts that compare well to GAPs manually generated by naval architects. The attendees at the presentation were generally positive, but also provided valuable feedback for further development of the WARGEAR tool and methodology. This shows the potential of WARGEAR to increase the speed of detailed layout generation to a matter of minutes and to improve the early stage design process by providing early insight into detailed layouts and their design drivers.