There are lots of threads on COTH with this very question–I recommend doing a search and reading some of them, because they’re filled with good advice / good questions to ask. You’ll find that most of the advice skews towards “Don’t do it.”
I don’t think I’ve seen this mentioned upthread, apologies if I missed it: by taking in a boarder, your homeowners insurance policy will need to be replaced with commercial insurance which is a lot more expensive (i.e. it’s not enough to just get a CCC policy). Do not try to skimp on this-- get the insurance you need.
Since this horse is getting injured a lot, do you know the general story about why/how it’s happening? Is the horse a fence tester, or is a pasture bully that gets into frequent fights? Is it possible your friend is overreacting to the usual assortment of bumps and scrapes that pastured horses accumulate, and blaming them on the barn? Or is that other barn genuinely unsafe? I would just be sure that you’re getting the straight truth on this-- in my mind the frequent injuries may be a red flag.
When someone hates their boarding barn, there’s often two sides to that story. Boarders sometimes have unreasonable expectations, a flair for drama/conflict, etc. It’s really good that you do know her already, but the dynamics of a friendship can change unexpectedly when you take on new roles, and especially when money changes hands.
I would tell your friend that you may be interested to start a boarding operation int he future, but now’s not the right time because you need to carefully consider the costs and how to make it work well. It’s a good message: “I want to make sure I do this right, because your friendship is important to me.” She can board somewhere else for a year, or 6 mos or whatever. In the meantime, you should write a proper business plan, do all the math you need to do on costs for feed, hay, property maintenance, insurance costs. Make sure you value your time appropriately because the biggest red flag in this thread is that you’ve said you don’t want to just take on more work unless you’re making a profit. So make sure you know what your labor is worth to YOU. Not to anyone else. A standard boarding barn tends to use very inexpensive labor for the barn work. You are not inexpensive, AND you can’t spread your costs out over a bunch of horses. So this friend of yours has to bear the full burden of paying for your labor. She may not like that. Don’t budge on this point, since you’ve identified it as a priority.
In the end, the urgency you feel right now is not real. You have plenty of time and need to approach this in a more thoughtful way, rather than scrambling to react to this one friend’s predicament. Let’s say you take 6mos to work out a plan: even if your friend finds a more permanent situation and chooses not to come to your barn when you’re ready, there are many potential boarders out there.
Last point: you say you could use the money. I can almost guarantee that you could find a second job, something like part-time retail, or a call center or something like that, and earn more than what you’d clear from the boarding operation–with less work and less risk of friendship strain. So do that for 6 mos while you work on your business plan, and then you’ll have a great perspective and knowledge base to decide how to move forward.
ha…