[QUOTE=Elegante E;3524079]
The only way to know for sure is to call around and get bids. Call the big names to get ballpark figures to start with. There is a difference between an indoor with just lights and one with bathrooms, maybe an observation lounge. Snow loads will also affect the cost as does building site. Make a list and call around.[/QUOTE]
I agree; I was going to suggest you get a quote from Morton, at least as a starting point, as they build a ton of these and are able to give very accurate and detailed quotes. Be very wary of quotes that come in at the extreme high or extreme low side, and make sure you are comparing apples to apples when deciding. I have had work done by Morton and by other good companies and I have to say that although Morton quotes have occasionally taken my breath away, what I have found is that frequently they are much more realistic in the true cost of the job than other companies, and ultimately they are fairly competitive on pricing. I have had several companies initially give a fairly low bid, only to spend the next several weeks on the job explaining why all of a sudden something they did not plan on is going to cost more. Also, Morton and other similar companies tend to be very good about adhering to the schedule and completing the work on time.
I would think you could get a nice indoor done for well under 600K; my outdoor all weather arena was 45K and had we intended to cover it, it would have cost less because we wouldn’t have needed to do all kinds of things to ensure it could be rideable in bad weather. My barn, which is 48 x 80, is a Morton and was significantly less than 600K. I know that wider trusses, necessary for an indoor, drive the price up a lot, but my barn is also kitted out inside, which would not be the case for an arena. My guess would be more like 350K, but that is just a guess based on my own experiences.
Re size of the arena – I wouldn’t do anything smaller than a small court (20m x 40 m, plus a little extra around the perimeter) as an absolute minimum, and even that is tough with more than a couple of horses in it at one time (and practically useless for jumping). Also, do note that a full size dressage court is 20m x 60 meters, which is 66 ft x 198 ft, so significantly smaller than the 100 x 200 you mentioned. Given that widening a building is more expensive than lengthening it (due to the type of truss required to support a roof on wider buildings), you may very well be better off sticking closer to full court size than the 100 x 200. That said, I think 100 x 200 would be udeal if you could do it.