Prefab ADU with Bathroom

Accessory dwelling units are becoming more widespread as the demand for affordable housing grows. They’re incredibly popular among the “indoor-outdoor” living style fans. Many people choose a prefabricated (or simply prefab) ADU. It’s a house partially constructed in a factory and assembled on the working site, which is often very convenient.

In addition to that, one of the most popular ADU client requests is a comfortable, high-quality bathroom. What is a prefab ADU, and what type of bathroom can it have? In this article, we’ll talk about this in detail!

Prefab ADU Types

There are two types of prefab ADUs: manufactured and modular.

Let’s look at each one of them:

1. Manufactured. Earlier, such houses had the name “mobile homes.” These are buildings entirely constructed in a factory and transported to the site by a delivery truck. With a rather limited assortment, large customization of such a house is practically impossible. However, they’re the fastest to get done since they basically don’t require any backyard site work. Another great advantage is that the installation process won’t bother your neighbors, unlike a stick-built house construction;
2. Modular. In this case, only separate parts of a house are ready, not the whole building. The working team brings the walls, the roof, and other elements to your backyard and assembles them there. Of course, this process takes longer than a manufactured ADU installation, but in most cases, it’s still quicker than the construction of a traditional house.

In addition to that, the aforementioned ADU types often differ in terms of appearance. A manufactured dwelling unit looks more like a classic villa with beams and a slanted roof. Meanwhile, modular ADUs have a more modern, “boxy” look.

How to Choose the ADU Type

How do you decide which ADU project type is the best for you to purchase – prefab or stick-built?

For this, all the customers need to consider several important things. Ask yourself:

• Is your backyard landscape suitable for a prefab ADU? Are there any hills or slopes?
• Do you need an ADU as soon as possible, or are you ready to wait for some time?
• What are your financial possibilities?
• How much value do you want to add to your property? Usually, the value of stick-built homes is higher, but a prefab villa can also make a property significantly more valuable.

Prefab ADU: Customization Possibilities

Possibilities of prefab ADU customization are quite scarce. Typically, there’s a limited range of unchangeable floorplan variants, and choosing the most suitable one can be difficult. You won’t be able to modify the placement of doors, windows, and other large construction elements. It’s only possible to make minor cosmetic alterations such as interior design or installation of awning windows instead of ordinary ones. That’s why many customers prefer stick-built ADUs.

Also, it’s important to mention that one of the main factors in house planning is the landscape. And here’s the biggest downside of prefab ADUs: unlike stick-built ones, you can’t adjust them to uneven ground. If it’s an attached unit, you’ll also need to adjust it to your primary home, which is also impossible in the case of a prefab unit.

Prefab vs. Stick-Built ADUs: Time and Money Expenses

Many people think that the costs of prefab ADUs are always lower in comparison to stick-built ones. However, it’s not so simple. With tiny houses, this rule really works – especially if such a house fits the property landscape. However, in the case of larger houses, the affordability is often comparable.

When planning the budget of your ADU project, don’t forget to include all possible expenses, including not-so-obvious ones. Consider everything in detail, from city permit fees to the price of interior finishes and materials. It will help you optimize the costs and avoid any extra charges. Moreover, the majority of prefab ADUs require a significant deposit upfront, and it may be harder to obtain financing for such a house.

As for the construction speed, this question is also a bit complicated. Yes, the site work takes less time, but the whole process — from the permitting to moving in — can also be relatively similar. Oftentimes, there are long queues for prefab ADUs, which can increase the waiting period too.

And now, let’s talk about bathrooms in prefab ADUs.

Prefab ADU Bathrooms

Prefabricated ADUs with pre-installed bathrooms have become quite widespread. Their popularity is understandable — if a house already has a ready-made, high-quality bathroom, you won’t have to spend time and effort installing it yourself. So, this solution is super convenient.

How many bathrooms can there be in a prefab villa? If you think “only 1 bathroom”, you’re deeply mistaken. Just as an ADU can have more than one bedroom, it can also have multiple bathrooms! An amazing variant is a full bathroom with a shower or a bathtub plus an additional half-sized one that has only a toilet and a sink. One of the bathrooms can also include a dryer, closet, or washer. A very convenient floor plan is several bedrooms, each bedroom with its own bathroom.

Another variant is a studio ADU with an open floor plan and minimum partitions. In such a building, the bedroom, the bathroom, and the kitchen are in one space. A great variant for those who love the “indoor-outdoor” living style! However, if you don’t like the idea of kitchen and bathroom appliances (a dishwasher, a washing machine, etc), standing right in your bedroom, this option is not for you.

As for the design of your bathroom space, we’d recommend you select neutral colors such as white or beige. They can be a universal background for your own design touches. Also, consider maximizing the space. Even if it has a few square feet, you can use the most out of it. There are plenty of ways to do it — for example, by utilizing vertical surfaces. You can attach the faucet, the towel bar, fixtures, and various high-quality appliances to the walls. Also, you may put a big basket under the sink to store toilet paper towels or other things.

Frequently Asked Questions — FAQ

What is the cheapest option for an ADU project?

One of the most affordable ADU options is a converted basement or a garage. It’s cheaper since it doesn’t require construction work — the structure already exists. Also, a prefab ADU can be rather cost-effective, especially if it’s small and fits the landscape.

What is the smallest ADU you can build?

The tiniest ADU that you can construct in California is a 150 sq. ft one. According to state laws, it’s the minimum allowed size of an accessory dwelling unit, no matter which type it is – attached, detached, or converted. As for the maximum ADU size, it’s 1,200 square feet for ordinary ADUs and 500 sq. ft. for junior ADUs.

Can I convert my garage into an ADU in California?

Permitting rules and building regulations vary slightly from one local jurisdiction (city or county) to another, but converting a garage space into an ADU is legal all over the state. Also, you can turn your basement or attic into an accessory dwelling unit. These ADU types are very popular because they don’t involve constructing a house from scratch.

How many bedrooms can an ADU have?

If an accessory dwelling unit is 1,000 sq. ft or larger, it can have more than one bedroom. The biggest number of bedrooms in such a unit doesn’t have any strict limits. For example, there can be several half-bedrooms with small space and compact appliances.