Modular Terrace Kit MTK2 Grimy Stone Terraced Back Yard Cobbles
The Back Yard allows a bit of variation to the cottages, since you can 'slide' it into the back of the cottages to give yards of different length, and also turn it through 180 degrees to give different openings of the gates. You'll need the Back Yard Wall to complete: two for the first pair of cottages, and one for every added thereafter.
The screenshot shows all the parts for a row of four GS1 cottages in exploded form: the image is also available in larger size, along with an example of a completed kit, in post #20 in this forum thread: