I've avoided borrowing from tsp all these years for all the reasons given at the links valkyrie provided. Am considering breaking the rules this year if it makes sense to break them, not sure yet. May have found the perfect retirement property last night. requires further research before I make any moves. cost of running power, water from 2-3 lots over, how many gpm the community well provides, how many acres allowed to water, HOA restrictions on use of land, IS there an HOA? there's a lot 2 over that has been used for small business, could still be used that way or as residential-has all utilities already due to past use. not interested in that lot, but if that one could be used mixed, maybe this one could be as well. decent road access, still rural. also need to investigate: soils, depth to bedrock, perk test for septic, etc.-the former commercial property has some very solid rock outcrops visible on the upper slopes. I like what I see. price is steep still but just came down by 30%, now it matches neighboring lot prices.
If I took loan from tsp, wouldn't be til fall, after had a chance to visit lot in person, ask more questions in person, if lot still available by then. would plan to pay off in 3 years-by intended retirement date. would mean serious belt tightening, but could pay off out remaining loan out of current Roth if job ends sooner than expected. By end of September this year-no early withdrawal penalties if not paid off prior to retirement. own property free and clear by retirement. that's my current thoughts. plan I wouldn't be considering at all if contingency factors weren't in place before pulling any tsp to finance the downpayment @ ~60%, 15yr fixed for the remainder. build once I'm ready to sell where I am currently.
Other option would be to only put down 20-30%, pulled from existing Roth.