What is the difference between an ADU and a JADU? Although they may be somewhat alike, an ADU and a JADU are two different types of living units.
An ADU is a dwelling unit you’ve constructed on your property that provides additional living space. A JADU, on the other hand, is a unit you construct by sectioning-off space within your home’s existing floorplan. A JADU does not increase the living space of your home.
If you live in the state of California, you can build either of these structures easily without too much trouble. The regulations are easy to meet and you don’t need to pay for additional land.
To make it even easier to construct an ADU on your property, the state laws do not even require you to have extra parking. If you are building an ADU to rent out to tenants, they can park in the street if it is possible.
Before we delve into the technical aspects of ADU construction, let’s find out the main differences between ADUs and JADUs. We will start by defining the two.
What is an Accessory Dwelling Unit?
Accessory dwelling units go by other names such as “in-law units” or “granny flats.” Generally, an ADU is a housing unit that consists of a room or rooms that can be designated as separate dwelling units, rented out for additional income, or used to accommodate elderly relatives.
ADUs are built on single family homes as directed by the permit, without the need to have parking or any additional infrastructure. While the city planning regulations are a bit restrictive when it comes to the development of JADUs, it is a bit flexible and accommodating for ADUs.
You can build an ADU for your elderly parents. You may also build it exclusively for renting purposes. Some people may build these accessory dwelling units, move into them and rent out the primary dwelling unit. It does not matter why you build an ADU because many states consider it as one of the affordable solutions to housing problems.
How Big is an ADU?
This is another area where ADU’s stand apart from junior accessory dwelling units. First, there are size restrictions in different states. However, we go by what is acceptable in California because it was one of the first states to simplify the development of these units.
Often mistaken for a tiny home, an ADU is quite different from a tiny house. First, a tiny house can be as small as 100 square feet. It is also preferably built on wheels so that it is classified similarly to a camper.
When it comes to an ADU, you should keep it to a minimum of 400 square feet. However, it can be as big as 1000 square feet. Unfortunately, it is not supposed to exceed that size.
The guidelines for the size of the ADU are very clear. The ADU can be as big as half the size of the PDU. Therefore, if your PDU is 2000 square feet, you are allowed to build an attached ADU of 1000 square feet. However, since you cannot exceed 1000 square feet, even if you have a PDU that is 3000 square feet, you cannot make your ADU 1500 square feet.
ADU size also depends on the type of accessory dwelling unit that you are putting up. For example, a detached ADU can be built to a maximum size of 1200 square feet in some places. However, even if you have a lot of space in the single family home lot, you are not allowed to exceed that size.
What is a JADU?
JADU is the acronym used for Junior Accessory Dwelling Unit. It is an accessory, not a main dwelling unit which cannot exceed 500 square feet.
While you may build an ADU and rent it out, you may not rent out a JADU. This one is reserved for owner-occupancy. The junior accessory dwelling unit must be contained in the same footprint as the regular residence.
A few years ago, you could only create a JADU by converting the extra bedroom into livable space. Today, that may not be the case.
A junior ADU must be on the same footprint as the main residence. Therefore, if you have an attached garage, you may convert it to a junior ADU but it must not be detached.
Just as with all housing units, even JADUs are regulated but not as strictly as the other housing units. There are rules and regulations you have to learn about before building a JADU.
Requirements for a JADU
- A JADU cannot be bigger than 500 square feet.
- This unit must be within a single-family dwelling unit or within another accessory structure such as carport or garage. However, many states require that the garage be attached to the PDU.
- The JADU can extend by a maximum of 150 square feet from the existing PDU. This expansion must only be for the ingress and egress (entry and exit).
- A JADU must have an entry/exit that is separated from that of the main house. Therefore, this unit stands without much interference from the main residence.
- A JADU does not have its own bathroom. Occupants can use a bathroom in the PDU
- The JADU should meet certain requirements for the kitchen. For example, it should have a 16 by 16 inch sink and a drain that is at least 1.5 inches in diameter.
It must not have appliances that operate on propane gas and it must have a counter and cabinets that can be accommodated by the available space.
- The appliances in the kitchen must not require the use of an electrical service that is higher than 120 volts.
- Parking space is not a prerequisite for a junior accessory dwelling unit.
Types of ADUs
Accessory dwelling units come in two types. Each has its own unique benefits that the other might or might not offer. However, they are both larger and more spacious than a JADU.
Attached ADU
One of them is the attached ADU that shares a wall or walls with the PDU. Usually, this rents out at a lower rate because it is not a secluded place and may not offer enough privacy. This type of ADU should also not exceed half the size of the PDU. It should be a maximum of 1000 square feet in many places such as in the state of California.
An attached accessory unit can use the water and electricity of the main house. However in some cases, the owner can install a separate power service, thus keeping the electricity lines separate, but still able to control everything from the main meter box installed on the walls of the bigger house.
It is recommended that this kind of ADU be attached to the main house. It can also be a garage that you no longer use converting it into an accessory dwelling unit. However in this case, the garage must be attached to the primary dwelling unit.
If the old garage is not in good condition, you may want to consider bringing down and building a new one with stronger walls constructing a proper ADU. If the garage is in great condition and can convert into a good ADU, you may want to start considering building an ADU.
Depending on the lot, you can have more than one ADU on it. However, you are going to affect the resale value of your home greatly if you have more than one ADU in the lot. In any case, you can always speak to a city planner to know whether you can have more than one ADU on one lot.
When you build your attached AD, you must remember that the entrance cannot face the same direction as the main house.
Detached ADU
The second type is the detached ADU. This ADU does not share walls with the main residence. It is recommended that a detached ADU is set at least 10 feet away from the main residence.
A detached ADU can be at a higher renting monthly rate. It offers more privacy since it does not share walls with the main house. However, its water and waste management bills can be shared with the main house. It does have its electricity service installed so that it runs independently from that of the main house.
If you have a garage that is detached from the main house, you can build an ADU above it. This means the cars stay below while a tenant or your elderly relatives live in the upper rooms. As long as the garage is detached, this ADU will also be considered a detached accessory dwelling unit.
If you are going to build your detached accessory dwelling unit from scratch, talk to a contractor and a city planner. As you speak with the contractor and city planner, they will highly likely give you a quote and provide you with more information on the rules and regulations that you should adhere to.
Detached ADUs cost more money than attached ones whether renovating an existing accessory or building it from scratch. For example, an attached unit can cost you $50000, and a detached unit can cost about $85000.
ADU vs JADU: Similarities
These both units serve a cost efficient purpose. Despite their differences, these two types of dwelling units have a few similarities.
1. Attached dwelling units can share the walls the same as a JADU can. You can have the JADU in the same footprint as the main dwelling unit. However, even if they share walls with the main residence, they have their entrance and exit separate from the PDU, for exterior access.
2. Another similarity is that the attached ADU and JADU can share the same electricity as the main house. Usually, this does not happen for detached ADUs, which mostly get their own power service.
3. You can have both ADU and JADU on the same lot. Because two ADUs are not allowed in one single lot due to rules and regulations, You may want to consider building an ADU and a JADU.
4. When building either of these units, you are not required to offer parking, at least not in the state of California. You are also not required to add any new infrastructure. Since the attached ADU and JADU are in close proximity to the main house, They share most of the amenities.
5. Both ADUs and JADUs are great for extended families that want to keep together. For example, you can build either of the two and bring your elderly parents over to live in the extra living space.
What is the Difference Between an ADU and a JADU?
You have seen a few similarities between an ADU and a JADU. However, there are many differences.
ADU vs JADU Size
A JADU offers a smaller living space than what you would get from an ADU. According to regulations in many states, you can only make your JADU a maximum of 500 square feet, which is not too big.
With an attached or detached ADU, you can even have a maximum of 1200 square feet, which is a larger space and can house a medium-sized family comfortably. You can make your accessory dwelling unit as small as 400 square feet.
You can have a Detached ADU
This is another difference between these two units. Mostly, a JADU is always part of the PDU. This may be a basement, attic or other room that is converted to a dwelling unit with a separate door. However, an accessory dweller is different especially when you want a detached dwelling unit.
A detached ADU does not share walls with other buildings on the lot. This unit stands alone. It offers more seclusion and privacy and access to the exterior.
When it comes to an ADU, you decide what you want between a detached and an attached one. Although you have a broader option with an ADU, you want to consider which unit is best for you.
Depending on whether you want to make use of the entire maximum space that a detached ADU is allowed, you can have living space that is the size of what many modern apartments offer. Therefore, you can even build one with families as your target tenants.
Families living in a detached ADU will pay more rent, but they will have bigger facilities such as kitchen and bathroom. However, even if this unit is the size of modern apartments, the rent is cheaper than that of a condo or apartment.
Building Cost for ADU and JADU
Since a JADU is smaller, it will cost much less to build as compared to the detached or attached ADU. Your budgets most likely will be different when considering building either one of these units. In most cases, a JADU is a part of the bigger house, which means you are converting space that is already available.
It can also be part of an attached garage. When you decide to build a detached ADU, it will need more materials and hence more money. Your ADU budget can run to more than $200,000 while that of a JADU runs to even less than $10,000.
With an ADU, you are building an extra smaller house in your yard while with a JADU, you just need to add an Ingress and egress to any room in your house.
You can ask your contractor to give you a quote for ADU and JADU and compare the prices. You will see a great difference between the two.
Power appliances
In a JADU, you can have appliances that use a maximum of 120 volts. This is why you do not need an extra power service for a JADU. It shares electricity with the main residence. However, an ADU can be a fully-fledged apartment with its own power and different types of appliances.
It can also have a big kitchen, a bathroom, and up to 3 bedrooms. Therefore, most people find more sense in installing a new power service for the ADU. This is accompanied by a dual meter box from which the power to the main house and the ADU can be controlled.
Private Bathroom and kitchen size
An ADU has a private bathroom while the JADU is not required to have one. The user shares bathroom facilities with the main residence. However, it is required by the law for a JADU to have a small kitchen, cabinets and a sink. With an ADU, you can consider it the same as renting a small or medium-sized apartment and therefore you get all the amenities that a full house comes with.
Wrapping Up
What is the difference between an ADU and a JADU? You have seen there are many differences as well as similarities. If you have the resources to build an attached or detached ADU you probably want to consider building an ADU.
If you are on a slim budget, you can think of converting one or two rooms of your main residence into a JADU. Both of these units offer more affordable housing options. Therefore, start planning to build one today.