You may buy the two houses. You may tear the two houses down.
You may not legally combine the two lots without the approval of the city in which lots are located.
Even if you build a house on one of the lots and use the other lot for a pool or play area, place a patio on the lot and use it in conjunction with the other lot, if you decide to sell the lots they would still be listed as two lots.
Looking at them someone might think they would be legally joined, however., not legally by the city, you could be financially liable for advertising the property.
In order to successfully combine the two lots and build a single family or 1-4 units on the property you must partition the city building and permit department.
This is really not a difficult thing to do, as long as you are not attempting to change the zoning of the property.
You might even do this yourself without having to hire an attorney as you would if you were attempting to change the zoning.
I hope t his has been of some benefit to you, good luck.
"FIGHT ON"
You do not necessarily need to combine the lots into one to build a single home on it. My home is on a double lot, but I do not know if my home built 1910 was built before or after the land was subdivided into lots. It only overlaps the other lot by about 1.5 ft. But it could be a good place for a tear down if someone wanted to build a larger home on 1/2 acre (adjacent 1/4 acre lots).
Lots adjoining your residence all lump together for state property tax credit in my state.
The process you are referring to is called "assemblage". It is usually only done to obtain the highest and best use of the land. For example, one might combine two or more residential lots, rezone, and construction a strip mall. In economic terms, you may find that it will reduce the resale value. Compared to renovating the 2 separate homes.
Certainly the opposite, adding a second rental unit to an existing property is a much more common process.
You would want to start by searching your local zoning laws.
Merging properties discussed here
http://appraisersforum.com/archive/index...
http://www.city-data.com/forum/real-esta...
It's "legal" if you get the necessary permits. In some cases you would need permission to tear down either house. In MOST cases you would need permission to "combine" two parcels (sometimes called "voluntary merger") unless you are building an approved "duplex" using a jointly-owned party wall between them. Many zoning laws only allow one building/dwelling per parcel and require "minimum setback" from all property lines, unless a variance is granted, upon proper application and after public hearing, etc.
You would need to speak with your local officials or land use attorneys to outline a plan to accomplish your goals.
Only if you get approval to combine the two lots
You would have to get it approved by the city I'm pretty sure.
You could if you are allowed to join the lots, not guaranteed you could.
If the zoning board allows it, sure.
You will need planning permission first (UK)
Is it legal to buy two houses side by side then knock them both down & turn both lots into one big lot?