Exterior facilities are generally difficult to estimate without further details. This includes paving the driveway and courtyard (how large in each case?), possibly the entrance platform (how many steps? what material? handrail?). Terrace (what size? what material? what subsoil? A terrace must be frost-proof, which is not exactly cheap). Rainwater drainage (drainage/infiltration? rainwater cistern?). Protection of the facade (gravel strip?). Privacy screen (hedge? palisades? fence?). I did our exterior facilities together with a buddy. For 3 months every Friday 6 hours and Saturdays 12 hours. Often another friend helped as well. Nevertheless, the fun cost 10,000 euros, although my buddy owns all the tools including an excavator and I only paid him a small price for using them). And he worked for free, because I also helped him with his house construction for a good 100 hours. So I only had to pay for materials + tool wear. It all adds up, don't underestimate that. My two friends also had to be supplied with drinks and food. On Saturdays, we quickly went to the chip shop and 20€ went for each lunch. In the afternoons, sometimes a piece of cake, in the evenings a few bottles of beer or a cutlet on the grill...