Example implementations relate to map generation and alignment. For instance, a computing system may receive and use sensor data indicative of positions of multiple markers positioned relative to a sensor within an environment to determine a pose of the sensor and also create a map that indicates the markers positions. The computing system may also receive and use subsequent sensor data indicative of distances from the sensor to surfaces in the environment and the determined pose of the sensor to determine an occupancy grid map that represents the surfaces within the environment. The computing system may then determine a transformation between the map of the markers and a design model of the environment that relates occupied cells in the occupancy grid map to sampled points from the design model, and provide the transformation between the map of the plurality of markers and the design model.