Plumbing not on shared walls. My neighbor’s leak shouldn’t damage my drywadrywall,, floor, or stuff.

Intense soundproofing. Structure as independent as possible so if one half burnt down, was damaged/was demolished it would not destroy both halves.

A lot of cash. Unless you have a record with the bank for building on spec.

I think the land would need to be zoned for multi family housing. That will vary based on locality.

I think the land will need to be zoned for multi family housing.

No bedroom on divider wall we rented 1 when younger very entertaining I’m sure they are built better now but it was like living in a comedy 😆

Foundation ( if needed in your geographical location) design would be different too to account for the separate units.

I would put a lot of focus on outdoor living arrangements too.

The best ones I have seen have the garages attached and the shared interior walls are the utility areas so that the living spaces are not conjoined.

I was just going to say the same thing as devonfield. :) I have a small developer near me building duplexes, which look like pretty decent SFH that just share a garage wall.

I don't know what the advantage is to building a duplex that way though. If all you're sharing is one common garage wall, what does that get you that 2 SFHs don't..? It can't be that much cheaper...?

Closets on the shared wall as possible.

A good idea.

Plumbing not on shared walls. My neighbor’s leak shouldn’t damage my drywadrywall,, floor, or stuff.

Hmmm, something I hadn't considered.

Intense soundproofing. Structure as independent as possible so if one half burnt down, was damaged/was demolished it would not destroy both halves.

Yes, I was thinking of that when I said "fireproofing" between ... more than just fireproofing though.

A lot of cash. Unless you have a record with the bank for building on spec.

Thanks, I do happen to have a lot of cash.

I think the land would need to be zoned for multi family housing. That will vary based on locality.

Hmmm again, I have a lot of land, and my county is funny about dividing land ... but this would remain in my name alone. Yes, must investigate this. Not something that was on my radar.

I think the land will need to be zoned for multi family housing.

Multiple families live on this farm now ... in several houses. But a mutiple family dwelling is different. Yes, this I must investigate.

No bedroom on divider wall we rented 1 when younger very entertaining I’m sure they are built better now but it was like living in a comedy 😆

Yikes, hope it was G-rated comedy.

Foundation ( if needed in your geographical location) design would be different too to account for the separate units.

I would put a lot of focus on outdoor living arrangements too.

The best ones I have seen have the garages attached and the shared interior walls are the utility areas so that the living spaces are not conjoined.

Two separate foundations? I didn't see that coming.

Yes, I'm thinking about the approach /entrance as a part of the "outdoor living arrangements".

I wasn't thinking of a garage.

By separate foundations I think they may have meant a concrete wall supporting the firewall. The code people would probably be looking for that. Do I recall correctly that you are working on a really unique living situation involving your children?

We have owned and gut renovated several duplexes (but not built from scratch). As mentioned above the first step would be to find out if the zoning allows it. As investors, the value (and profit) to us in owning these duplexes was in condo converting them. Then we could sell the units individually instead of as one property.

We did it! Reveal here plus ‘Terrace’ level finish. We built in town, not on our farm, (which is several states away), so zoning was an issue. Luckily, duplexes or townhomed/condo duplexes which allow for separate ownership of each side are very popular in the area and all but a few of the largest and best (creekside and bordering open space) lots in our target subdivision allowed duplexes. Although resale was very much a secondary factor, we did build so we could convert to townhomed (separate ownership per side) with resale in mind — with firewalls in place all we would need to do is close up a few doors between the units (double fire doors now). We have separate utilities and heating already in place. I do miss having separate windows on one side, but that’s a very minor compromise given the benefits for our family. No separate foundations were/are required. Honestly, in the four years since we built the value has more than doubled what we have in it (by a lot!), but not planning to sell, so at this time that’s a moot point. Hopefully, resale would be the kid’s problem (or boom).

Now, on a family farm and even assuming you live there for your lifetime, if your heirs don’t want to want to sell the farmland or live there, I wonder that if in the future it might be a white elephant. Think about who is going to live in it after you are gone and/or what would resale look like?

Edited to add: I don’t know your particular situation, so my comments regarding building on a family farm are just based on a generic situation.

The reason two-family dwellings are zoned for and built, is to maximize the density of the neighborhood. You are building two separate single family homes joined at the hip, but usually at a much smaller scale and with less amenities, which is necessitated by the smaller lot size in that zoning to achieve the tighter density. In a wide open rural parcel, I don't see much advantage to doing that, but certainly could be a disadvantage even if it could fly.

By separate foundations I think they may have meant a concrete wall supporting the firewall. The code people would probably be looking for that.

Ah, that makes more sense.

Do I recall correctly that you are working on a really unique living situation involving your children?

No, not at all.

Quick run down: I am one of five children. Our grandmother left us two farms located about a mile apart. My middle brother and I own the main farm; two other siblings own the second, slightly larger farm; and the fifth sibling inherited nothing. Why the inequality? M has always been financially irresponsible -- no need to go into details.

Years ago our grandmother called us together to talk about passing on ownership of the farms /which of us wanted which pieces of land, and -- in a moment of clarity -- M asked our grandmother to leave the land to the rest of us, saying anything in his name would be lost to creditors.

Now we've reached a crisis point: M has several health problems (which come from poor diet and general lack of attention to his health), but now he's suffered a real problem that will probably lay him low -- we anticipate him going on disability. He can't support himself now working; he's going to be in real trouble. I hate to say it, but the other four of us will outlive M.

My brother and I have talked about building a modest duplex on our farm -- it would be in our names, not M's. Our thought is that each of us would pay half, and M would live in one half, while the other half provides some income. Rental places in this rural area are hard to find. Our uncle, who owns yet another family farm, owns a duplex; his son lives on one side, and he has a good long-time renter on the other side but receives several inquiries per year about renting the place.

duplexes was in condo converting them.

Um, what's the difference in a duplex and a condo? I'm afraid I don't know.

I'm thinking codes and restrictions will be fairly lenient; our two farms are in a small area that incorporated for the sole purpose of avoiding being "taken in" by any of the small towns that surround us -- fewer than 500 people live in this area, and we're all quite "do whatever you want on your own land". I'll be at a town hall meeting in a few weeks and can check on the legal requirements.

Actually, our farm already has one farmhouse with a one-bedroom apartment on the side. Is this a duplex?

We did it! Reveal here plus ‘Terrace’ level finish.

Thanks -- I'll read through this information with interest.

I wonder that if in the future it might be a white elephant. Think about who is going to live in it after you are gone and/or what would resale look like?

Since we're talking about old family land, which will not be sold, I want to build something that will appeal to the family in the future. Above I mentioned a one-bedroom apartment. That place has been used for numerous purposes over the years, so I feel sure this would be useful either for family OR rental.

That's why I don't want to go the cheapest route and plop a trailer on my farm.

The reason two-family dwellings are zoned for and built, is to maximize the density of the neighborhood.

Well, that is one reason people build duplexes.

Duplexes were a fairly common thing when I was growing up in this rural area, and most of them were built by people who were occupying one portion /renting the other. Or people who wanted a home for their family and a place for grandma right next door (the one-bedroom apartment mentioned above was originally built for our great-great-great aunt). Some of these places are on farms or large lots. Single family dwellings are the most common living choice in our area, but duplexes (or triplexes or quadplexes) aren't unusual.

Anyway, we're kicking around this idea /trying to decide whether this is a good choice for our family. We're far from decided -- thanks to all who've thrown out thoughts for us to chew upon.

You know the area better than any of us do so perhaps a duplex is financially feasible. I'm more used to duplexes and semidetached houses being thrown up to maximize the use of space in urban environments where middle density housing is the objective.

Perhaps it might make more sense to just build a small cottage or ADU for your relative, with a view to renting it out at a later stage.

A duplex normally has one person owning both halves; a condo has separate titles for each unit. I think that's the distinction people are making.

I think it sounds like a great answer. If you look up modular home plans there are a lot of plans for duplexes. I would start there to get some ideas, as most of those are designed for the rental market. You won’t find as many in the online plans for sale. Between the two you can probably find something that would meet your needs. In fact, this sounds to me like an ideal opportunity for modular built. In fact, it sounds as if a triple might be a great opportunity. And that there probably would be a good demand. A lot of plans are for 2 bedrooms, but I might consider having a 3 bedroom that could be used for family. Be sure to become well informed on what makes a good lease and how to select tenants. Check out MrLandlord . com for more information.

Perhaps it might make more sense to just build a small cottage or ADU for your relative, with a view to renting it out at a later stage.

I hear you, but our thought (just a thought, no math behind it yet) is that building a duplex wouldn't be all that much more than building one small house ... and the duplex would give some income. At least, that's our naive thought process.

A duplex normally has one person owning both halves; a condo has separate titles for each unit. I think that's the distinction people are making.

Okay, good to know. So if my brother (not M) and I build this together, it'd probably be a condo ... each of us owning one unit, M living in one side /the two of us using the rental income from the other side to repay what we put in.

If you look up modular home plans there are a lot of plans for duplexes.

Great -- I'll look it up.

In fact, it sounds as if a triple might be a great opportunity.

Triple sounds like more income ... but also more up front. Another issue is that we already have a septic tank for a three-bedroom house, and we're hoping it'll do for this duplex.

A lot of plans are for 2 bedrooms, but I might consider having a 3 bedroom that could be used for family.

Hmmm, my uncle said just the opposite: he says that if you build more than 2 bedrooms you're opening yourself to children, who will be rougher on the house. His long-time renters are a couple with one son ... used to live with them /now is out on his own.

Check out MrLandlord . com for more information.

Thanks, I'll look into it.

Thanks again for all your thoughts, All.

Well, there is differing opinions on 3 bedrooms. Yes, it could open up to children, but a two bedroom does also. Even a 1 bedroom can under certain circumstances. But my thought was that you said maybe family would live in at some point. And I thought of family that had children. Also, a 3 bedroom increases the income quite a lot for not much more costs to build and an increase in demand. Also, you could advertise as 2 bedroom with office. That gets more money than a straight 2 bedroom. On the website I mentioned above there has been a lot of discussion about the “2-minute home inspection” that some landlords do as part of their screening. This can go a long way towards reducing the risk in damage from kids. The existing septic design for a 3 bedroom may be your limiting factor, though.

I have a mix of units (1, 2, and 3) and have not had damage from kids. Although we tend not to have many kids because our tenant pool has a lot of variety as our units are in a city of about 30k. (Students, professionals, lots of roommate situations) Your tenant pool might be heavily children in a rural area. As an example we have 2 3 bedroom units that has the third (attic) bedroom access through the larger second floor bedroom. Over the past several years in these two units we have had an unmarried couple with no children, two roommates, a single college professor, an unmarried couple who had his child from a previous relationship living with him, another unmarried couple, 3 college roommates, twice. Good screening is your first and best tool in preventing damage.

A dwelling is a fully intact building containing living facilities for either 1 or 2 units.

A duplex is slang for the 2-unit version, where they are adjoined horizontally, each with separate outside access. It can be a single ownership as 1 building on 1 parcel or split into 2 owners with individual associated parcels (often remodeling a single family dwelling to stacked vertical units are referred to as "duplexes," but that muddies the definition because it is difficult to separate ownership or comply with some code provisions). Duplexes fall under IRC code covering up to 2-units, which is an abbreviated code (and you can argue less strict). More than 2 units kicks you into the IBC, which is far more intensive.

A semi-detached house is a 1-unit version that touches part of an adjacent 1-unit version on a shared property line, but they are still recognizable as individual dwellings.

A townhome refers to a building with more than 2 units adjoined horizontally and/or vertically, each unit with separate outside access.

A condo refers to a building with more than 2 units stacked both vertically and horizontally, but all accessed from an interior hallway. Each one is individually owned but shares common spaces.

___________________

- A duplex is building more than just a small house. You have separate complete functions of living, kitchens, bathrooms, HVAC, electrical, and plumbing. However, there are usually savings over a larger house with the same amenities, because as I stated before a duplex is typically built to comply with tight site and zoning constraints, so everything may be at a smaller scale.

- A septic tank is sized based on # bedrooms. If your parcel will be divided into 2 for separate ownership, then you may need 2 septic systems and leach fields (and future reserved field area).

- If you have a large single parcel of family land that is undeveloped (no house there now), then it is not the typical solution to build a duplex (or semi-detached house) on a zero lot line. A big reason to live rural is to get away from urban density, get away from neighbors and noise. So that kind of defeats the opportunity. I do see many rural duplexes built on say 1 acre or so, but not a large 5 acres for example. At that point, it would be better to subdivide the property into 2 smaller parcels.

- Note the difference between a duplex (2 individual units with their own facilities in a shared dwelling) and an apartment (another unit in a single dwelling, but sharing some facilites like plumbing or HVAC).

Well, there is differing opinions on 3 bedrooms. Yes, it could open up to children, but a two bedroom does also. Even a 1 bedroom can under certain circumstances.

True, but fewer bedrooms would be smaller families. One child is a whole lot different from multiple children.

But my thought was that you said maybe family would live in at some point. And I thought of family that had children.

My brother and I are considering -- still just considering -- doing this for our sibling. He isn't married /has no children /I don't anticipate this happening.

Also, a 3 bedroom increases the income quite a lot for not much more costs to build and an increase in demand. Also, you could advertise as 2 bedroom with office. That gets more money than a straight 2 bedroom.

Worded that way, it sounds quite reasonable.

The existing septic design for a 3 bedroom may be your limiting factor, though.

Yes, in our minds we were seeing two 2-bedroom /1 bath units. The septic tank used to serve a 3 bedroom /2 bath trailer, so we assume it would serve a 2-bath unit, even if the units were separate.

Yes, this does limit us -- but it also saves us money. We're talking about two of us (upon whose land it would be built) bearing the brunt of the cost -- but our other two siblings are willing to kick in some money too, which they will never recoup. When the four of us inherited /our fifth sibling did not, our grandmother made us promise that we would be sure M is never homeless -- we are taking that promise seriously. We've talked about ideas previously, but now that he's on the verge of being disabled, that promise has taken on new proportions.

Good screening is your first and best tool in preventing damage.

So says my uncle.

A dwelling is a fully intact building containing living facilities for either 1 or 2 units.

A duplex is slang for the 2-unit version

Yes, so my brother's farmhouse with a one-bedroom apartment on the side is technically a duplex. I tend to think of duplexes as equal-portions, but that's not necessarily always true.

I was thinking two side-by-side units ... but a two units "stacked" could be an option too.

More than 2 units kicks you into the IBC, which is far more intensive.

Two units seems realistic to us. One for our brother, one to help us recoup a portion of what we put in. You've convinced me not to consider tri-plex or quad-plex. Not that that was really an option in play.

A semi-detached house is a 1-unit version that touches part of an adjacent 1-unit version on a shared property line, but they are still recognizable as individual dwellings.

So maybe my brother's farmhouse, with its apartment-across-breezeway is semi-detached. He and his wife own the whole thing.

A duplex is building more than just a small house. You have separate complete functions of living, kitchens, bathrooms, HVAC, electrical, and plumbing. However, there are usually savings over a larger house with the same amenities, because as I stated before a duplex is typically built to comply with tight site and zoning constraints, so everything may be at a smaller scale.

Yes, and we are considering SMALL. We're looking at about 900 sf on each side ... two bedrooms, one bath, large island with seating for eating ... and plenty of storage. Much like a small apartment and suited to M's needs.

A septic tank is sized based on # bedrooms. If your parcel will be divided into 2 for separate ownership, then you may need 2 septic systems and leach fields (and future reserved field area).

Hmmm, I was thinking of the number of bathrooms. That's bad news.

If you have a large single parcel of family land that is undeveloped (no house there now), then it is not the typical solution to build a duplex (or semi-detached house) on a zero lot line. A big reason to live rural is to get away from urban density, get away from neighbors and noise. So that kind of defeats the opportunity. I do see many rural duplexes built on say 1 acre or so, but not a large 5 acres for example. At that point, it would be better to subdivide the property into 2 smaller parcels.

We have a whole working farm ... with two existing houses, one of which has an apartment on the side.

I've lived in this area most of my life, and I assure you that the desire to "get away from neighbors and noise" is only one reason people move to rural areas. We are rather ideally located for an easy commute between two large cities and three moderate-sized towns, and we are right on the main road; also, our area is one of the fastest growing in the state -- I have no concerns about being able to rent.

For several reasons, subdividing is not realistic.

I did a preliminary design for a development made up of duplexes years ago. I connected each unit by the garage, so only the garage had a common wall. This eliminated sound transmission to priority spaces, and the combined driveway was almost large enough for a full basketball court.

I connected each unit by the garage, so only the garage had a common wall.

I agree that sounds ideal, but we aren't looking at building a garage. M hasn't had a car in years -- isn't responsible enough to maintain a car and insurance. In our climate a garage is a luxury, not a necessity.

Is that "M" as in James Bond's "M"?

Perhaps it could be laid out to have laundry rooms or other utility spaces join; or perhaps be connected by covered entry porches.

Building two units will pretty much cost twice as much as building one unit. It sounds like you want the second unit for producing income to pay for building (and supporting) the first unit. But first you have to use the generated income to pay yourselves back for building the second unit. How long will that take? Hint: a long time. You might be better served by investing the money you save by not building a second unit and put it in a trust to take care of your brother. "I hate to say it, but the other four of us will outlive M." You absolutely do not know this. Anything can happen.

Catbuilder is correct, don’t count on much, if any, economy of scale with building two units over two single famliy. Maybe a little bit, but not much at all. I do applaud your family’s efforts to fulfill your grandmothers wishes and take care of M.

Hi, All. I see this old thread popped up. Unfortunately, we have abandoned this project. We talked to M about it, and he's all about it ... but he wants to double the kitchen size and add a second bathroom. He won't accept that we can't afford to "do it up big" and isn't interested in the simple 900-ish square foot apartment-type dwelling we can afford ... even though he's literally on the verge of homelessness.

The worst in this situation is yet to come.

Perhaps it could be laid out to have laundry rooms or other utility spaces join; or perhaps be connected by covered entry porches.

Two units joined by a utility space makes a lot of sense.

It sounds like you want the second unit for producing income to pay for building (and supporting) the first unit.

That was our thought exactly.

"I hate to say it, but the other four of us will outlive M." You absolutely do not know this. Anything can happen.

Eh, yeah, but realistically, M -- though the youngest -- does not take care of himself. He doesn't work for a while, can't afford his insulin and other meds -- doesn't tell anyone. It doesn't take long for him to fall into a crisis and be hospitalized. He's an inpatient in the hospital at least twice a year.

In contrast, I'm the oldest but the healthiest of the five kids. I'm in great condition, eat well and exercise regularly. The other three are more like me than M.

Unless all four of us get hit by a bus together, M is unlikely to be the last man standing. The likelihood is that he will always have an older sibling looking over his shoulder.

I do applaud your family’s efforts to fulfill your grandmothers wishes and take care of M.

Thanks, we are trying to help him.

What about a temporary mobile unit, might be the least expensive option. Could be like a tiny house, mobile home or prefab. I really like the idea of a separate dwelling like a cottage or adu.