Price of Duplex

Asked by CA Mom, Mountain View, CA Fri Feb 26, 2010

If a duplex has similar numbers (sq footage, # of rooms, etc) as a single family house, but it's divided into 2 units, how does that affect price of the property, compared to a single house, assuming all else (neighborhood, condition, school etc) being equal?

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Arpad Racz, Agent, San Jose, CA
Tue Apr 18, 2017
I would be happy to research some local data in a very Specific area you are interested in, so you have actual data to look at between single family and duplex properties. Please feel free to email me.

Kind regards,

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Al1mind, Home Buyer, Mountain View, CA
Sun Apr 9, 2017
Are the HOA the same in duplex, as the single units?
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Flag Sun Apr 9, 2017
Robert Lei, Agent, Cupertino, CA
Mon Mar 1, 2010
Hi CA Mom,
If a duplex has similar total square footage, # of rooms, neighborhood, condition, school, etc as a single family home, the duplex will tend to sell at a lower price. That's because a single family home has almost universal appeal whereas duplexes/multifamily will only appeal to a fraction of the population.
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Marcy Moyer, Agent, Palo Alto, CA
Sat Feb 27, 2010
CA Mom,
The biggest problem with comparing with your parameters is that legal duplexes are not found in the same neighborhoods as single family homes for the most part. The city has to zone for multifamily homes so you can not put a duplex in a single family home neighborhood. That being said, right now multi family homes are selling for less than single family homes in similar neighborhoods. For example, I just sold a duplex in Cupertino in the Monte Vista area. It was in a very nice neighborhood of duplexes with Stevens Creek Elementary and Monte Vista High. It has 2760 sq ft on a 9K lot and sold for $1,150,000. A similar sized single family home on a similar lot would probably have sold for $1,250,000 to 1.3

Marcy Moyer
DRE 01191194
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Gilbert Rich…, , Santa Clara County, CA
Sat Feb 27, 2010
Frankly speaking Duplex's and Single Family Homes are compared much differently from one another. The reason being with property use and unit type being different there are different factors that could make a comparable duplex worth far more or less than a single family of the same size.

I suggest using a a property search like the Home Scouting Report where you can map comps of a specific type and see the differences for yourself.
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Lea Ann Hern…, Agent, Saratoga, CA
Sat Feb 27, 2010
Duplexes in Santa Clara County are not strictly valued as income property, but as a kind of hybrid between a single family home and multiple unit. They can be a great alternative to a condo purchase, assuming the buyer is somewhat entrepreneurial. Instead of paying homeowner's dues over which one has no control, rent is being collected. And you are able to deduct all operating costs and depreciation allocated to that portion of the duplex which is not owner-occupied. AND you can obtain an owner-occupied loan if you do intend to occupy it. There are advantages and disadvantages, but in today's economy...makes a lot of sense at the right price.
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Dp2, , Virginia
Sat Feb 27, 2010
First, the formulas for an income analysis (which is what investors, bankers, appraisers, and other professionals use to determine the value of an investment or business) are the same. Basically, one deducts all of the expenses--except the debt service and income taxes--from the gross income to get the net operating income (NOI). The NOI is the CFBT for an all-cash purchase, and it's the sum of the CFBT and debt service for a financed purchase.

Second, when everything is all said and done, a properly stabilized, professionally managed, income property typically will have net operating expenses in the range of 35% to 50% of the gross income. The older the property is, the closer one's expenses will be to that 50%. There is plenty of research available both on- and off-line for one to check out on this. You could also confirm this with any reputable property management companies. Furthermore, many investors (myself included) use this data to quickly assess how effectively a property is being managed.

Third, the yield (ROI in this case) is ratio formed by the CFBT (the numerator) and the total cash invested (the denominator [which included the down-payment, closing related costs, and any immediate repair costs if applicable]). If one is looking for a ROI of at least 10%, then one has to either purchase a property for at least a 10% cap all-cash, or one has to structure one's deal in a way that does the following: caps the initial cash invested, acquires the property at a high enough cap, and sets up the financing with with the right rate/terms.

I could write a lot more on this, but the goal is to show you that good deals are made--not found. It's probably good for you to sit down with a commercial agent to get a feel for that s/he has to offer, but I'd strongly recommend that you'd also attend at least one of your local REI club meetings, and network with several other investors, before you buy anything. They'll be able to tell you what they're buying, where they're buying it, why they selected the area, and how the investment(s) is/are working out for them.

Keep in mind that the numbers always work on paper; it's your job as the investor to ensure that they'll also work in reality, because it will be your dime on the line.
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Dorene Slavi…, Agent, Torrance, CA
Sat Feb 27, 2010
Hi CA,
Well, some other things come into play when evaluating income property. IF you work with a Commercial Realtor they can explain how we use formula's to determine the value of income property.
We have a formula that takes into consideration the income the property brings in, then subtracts the price that was paid for the property,taxes, as well as what it takes to maintain the property. That way, you can clearly see what kind of investment you are making, and what the return will be.
The better the return, the highter the value...all other things taken into consideration.
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Dp2, , Virginia
Fri Feb 26, 2010
I agree with most of what Dale wrote, but I'm not sure I agree with that "0.8% rule". Many investors I know (myself included) are looking for CFBT >= $100/month/door.

Let's say that you could get $2K/month/side. The following numbers are an estimate of what I'd be looking for in the deal; the actual numbers might be a little better/worse.

gross rent = 2($2K)(12) = $48K/year
NOE = $24K
NOI = $24K
min CFBT = 2(12)($100) = $2.4K
max debt service = NOI - CFBT = $24K - $2.4K = $21.6K/year (or $1.8K/month)
DCR = 1.11
max purchase price (at 8% cap) = NOI/.08 = $24K/.08 = $300K

Interesting enough 0.008($300K) = $2.4K, so Dale's figure for rent is in the same ballpark. (I'll have to play with that some more. :) )
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Dale Warfel, Agent, San Jose, CA
Fri Feb 26, 2010
Duplexes are considered residential income property, as opposed to a single family home. These properties are typically driven more by rental income. Since rents typically don't fluctuate all that much, the prices for income properties is typically more stable. To determine value/offer price, do a comparative analysis of other active pending, and sold 2-4 unit properties. Compare attributes such as the property condition, garage vs. carport, square footage, proximity, zip code, school district, age, etc. to come up with an estimate of the properties value. Another question is if the property is a legal duplex, or if it was a single family property divided without permits. That could create some big problems if the property was not a legal multi-unit property.

Another factor to consider is planned use. Are you considering living in one unit and renting the 2nd? From a pure investment, I like to use the 0.8% rule, that is, the collected rents should equal 0.8% of the purchase price each month, assuming 100% occupancy, to be considered a viable investment. There aren't many places in this county that will give that type of return.

I hope this helps. If I can answer any questions, please feel free to e-mail me at

Good luck,

Dale Warfel
Real Estate Consultant
Keller Williams Realty
M: 408-624-6202
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