Even if you had a friend or relative buy the other half it would be a bad idea. I know of two childhood friends who no longer speak because they bought a home together.
If you did do this, you need to have an attorney write up an agreement to clearify what happens when one wants to sell.
Believe me, no one wants to go into a real estate deal with someone they do not know, so trying to sell half later wont be a winner either.
Also, you need to qualify on your own, not from the income the duplex is bringing in. If it were 8 units, that would be different.
If you cannot purchase the duplex on your own, why don't you try buying a bank owned home or a condo? It's much better to own then to pay someone else's mortgage.
Values are down and money is at it's lowest level which make for a great combination.
I work in your area in San Mateo. Let me know if I can be of any help. You should also try and get pre-approved for a loan if you haven't already.
Dave Tap Tapper
You can buy half of a duplex.
If you set it up as a TIC (tenants in common) it would be the best to protect everybody and specify all of the terms and conditions. The other option is to find a partner who is looking for an investment or wants to live in the other half. Either way the banks will consider the income when qualifying your partner for the loan if he does not live there or if you buy the duplex and rent out one side.
City may allow 2unit sub-division into "condos".
For example the City of Menlo Park allows 2 detached single family homes to be built on some R1 lots under a 2 unit condo map - so it is possible.
This would be far better than doing a TIC.
TICs have not as of now been accepted on the Peninsula and even in SF they are considered poor second cousins to condos.
As a first time buyer, I suggest you keep it simple.
If you can get the property at a good price, the numbers for full ownership (including rental income for the other unit) should approach the numbers for half ownership no matter how you slice the pie.
Subdivision and TIC even if possible is going to cost you $5000 to $10000 easy.
Keep it simple - get a good price and it should make sense and owning it all will be much better than owning 1/2.
Without knowing the features, your needs and wants, the owners asking price, or even your personality, it is hard to say if one type of building would be better suited for you. In terms of the loan on both units as they are, you may not be able to use the full rental income to qualify. Feel free to email me your info(owners asking price, rent amounts, your debt, crdit, car loans etc. and I can look at your debt ratios, and give you an idea of how close you are to being able to afford.
You have received some good answers to your question and has been pointed out, co-owning can be a risky proposition. As has already been stated, you can be a co-owner and have a legal right to one of the two units. (of course both "owners" would have to agree on all terms and conditions) From what it sounds like, the current owner may want to sell 100% of the duplex, so this may not be an option for the building you live in)
I believe one the best vehicles for co-ownership is what is called TIC (tenants in common) ownership. This type of ownership is quite common in the City of San Francisco. Properly structured (and this requires the assistance of experts, including legal advice) TIC ownership is a possible solution. It is even possible to have separate loans, although this type of lending is available by only a few lenders and is more restrictive than the loans available for condos and single family homes.
With prices and interest rates where they are today a condo or townhouse would be a better choice.
I think you have an excellent idea!
First you can NOT buy just half of a duplex.
You could buy half the entire property from the owner - you each would be half owners of the entire building not a specific side - but having a partner is not always an ideal situation and I would not recommend it - too many problems.
Lenders will include the rental income from the other unit in the duplex for purposes of qualifying.
If you wish please contact me via email and I can run some quick numbers for you.
I would need to know price of duplex, how much cash you can put down, what your income is and what the other unit will rent for. When I have that info I can calculate for you payments and qualifying etc.
If it looks promising then I would put you in contact with a loan specialist to get you pre-arppoved.
I would also suggest you bring a real estate professional into the transaction to prepare the paperwork.
This can be done at a reduced cost.