Buyer Beware still applies.  Get a home inspection.

My husband & I have owned old house for twenty years but it had 'good bones' aka solid foundation & structure.  Still here & loving the location.

Better have a thorough inspection first so you know what you may be getting into.

I do this, know what you are buying and buy it at the right price and everything will be fine.

Inspections are key IMO

I would avoid buying without a inspection

Avoid fear.

run your numbers but definitely get a home inspectio

You should avoid getting screwed! 

Do your due diligence as far as running the numbers more than once, and in having the property inspected by a professional.

As you know, the main thing you should avoid: waiving your inspections. 

I did that and still live in the place.  They have their charms.  But there is so much hiding just waiting to self-destruct!

have a home inspection so you know the condition of the home

Avoid being taken advantage of - oh wait, you're a broker - you're good to go ;)

Paying for a thorough inspection would be the best protection.

Work closely with a home inspector you trust.

It all comes down to price....

  Don't buy a tear-down!  Get real numbers from contractors and sub-contractors.  Remember that one thing leads to another - that simple HVAC replacement might require a complete upgrade of the electric service.  That worn roof might be covering rotten trusses and supports.  Get everything inspected, including structure, termites, septic, and well.

Lots of people have done that type of business.  Make sure you understand what you are buying in your "as is" condition.  Have the property inspected by qualified inspectors so you know in advance what you need to fix.  Understand your costs upfront so that you will not lose money etc.

Depends on what you consider "old".  Old as in late 1800's/early 1900's have totally different problems then say 1950/1960's home....ex.... lead, asbestos, knob & tube wiring, galvanized pipes, etc.  Not much still around, but you'd be surprised.

Have a home inspector you trust doing the inspection and then add 10-15% to your budget to handle the surprises! Buy low and sell high!

It's not so much what you should avoid as what you should do.  Do your due diligence.  Get an home inspection.  Get a structural inspection if there is any question about the integrity of the foundation.  Many of the flipper type homes don't fall under the disclosure laws so beware and know what you are buying.  There will still be surprises but, hopefully, not the big expensive ones!

Got my start in RE that way. You must learn that every transaction is full of unknown surprises and expect cost overruns.

Avoid not getting a home inspection and any other inspections you think may be needed.

Get a home inspection.

If you're familiar with construction, you can get a pretty good feel for what any house will need. I always check wells, septic, survey plat, electric box and wiring, plumbing, attic, foundation, windows, etc. Compair repair costs with building new costs, and check local market comps. Also check basement for water damage, check zoning, make sure house isn't in a historic district. If addition is planned, check soils. A few years ago a man who bought a house and fixed it up wanted to add an addition, then resell. he called me about listing. I knew the area, and knew no additions could be added to homes in that area because they were in a " Sensitive Soils" district.

my focus has never been old homes....but if I were to guess, I would say to spend time in the basement with focus on the sills, foundation and supporting columns!!

Many people are making good money doing what you are doing and some are losing their shirts. Be sure to keep your shirt on.

Whatever you do...don't avoid a home inspection. That is a great way to find out information on the house. 

Every home in California is sold in "as-is" condition.  The buyer has the right to request repairs, the seller has the right to make any of the requested repars they wish, the buyer has the right to accept, reject or counter.  This goes on until there is an agreement or cancellation.  The only difference in buying a home in "as-is"condition is that you already know that the seller will reject all repair requests.  Just make sure you have a professional home inspection and go from there.

Avoid homes with big ticket items needing replacement or repair, like significant termite damage in structural members or significant water damage and warping. Other than big ticket items look at things outside your expertise that will cost too much to make your numbers work.

Mary Yonkers knows her stuff.

It could have been: a crack house (will cost you to have Hazmat tear it down) a sinking rotting mess (once you open one wall be ready to fix all the walls)  they may have done illegal funky repairs and you will search the world to find parts that fit then end up ripping it all out and going down the the county planning desk for permits.  Wishing you all good things.

Do it all the time.  I work primarily with investors.  The list of things you can find is unending.

If you are not a pro att his stay away or go to something with less work

Avoid the mistake of NOT having an inspection done.  You never know!

repair and retrofit cost.

Obviously a home inspection and follow up recommendations by specific contractors are very important.   

Aside from doing a good home inspection, it wold be prudent to check with the insurance company also to see if they will insure the old stuff or you will need to replace...like plumbing and electrical.

Eve

You should be as thorough as possible in your due diligence, including inspections. Never just assume everything looks alright

Andrey Sokure Check it out thoroughly before purchasing.

I do the same Andrey Sokure and it is not hat to avoid, but what to look out for and to make sure the purchase price reflects any work needed by deducting from value the repairs needed. 

Have an option to have the house inspected, and opt out if report indicates many problems.

Understand the risks of lead paint and asbestos.

Mary Yonkers nailed this one!