Different Types of ADU Floor Plan Designs

There are many different types of ADU floor plan designs. In this article, we’ll look at the styles available, including a Closed floor plan, a Split level with a covered parking space, and Custom-designed plans. Which type is right for your property? What features should you look for? Here are a few tips to get you started.

Closed floor plan

Many cities have adopted pre-approved ADU house plans – United Dwelling designs. These plans are reviewed for compliance with local building codes. However, depending on site conditions, some may be ineligible for approval, and certain elements, such as roof decks, may require additional setbacks in certain zones.  For pre-approved plans, some cities provide blueprints and “Approved Standard Plans” for future ADU builders to use. However, before you get too far ahead of yourself, make sure to read and understand the guidelines carefully. Depending on the city, the final plan may not be acceptable.

Split level

A unique design for an ADU is the Split Level home. The layout is a two-story plan that maximizes every square foot of space and is highly expandable. The upstairs features a flexible floor plan for sleeping, guest or study uses. The stairwell has tall windows that introduce ample daylight and cross ventilation. This unique design also allows for double ceilings, which makes the ADU feel more spacious than its actual square footage.

The Split Level house plan has two different levels separated by a short flight of stairs. The main level contains a living room, dining room, kitchen, and a staircase leading to the upper level. The lower level often features a finished area with additional bedrooms and space for storage. The basement serves as an ideal space for storage, while the upper class can house a bedroom or two. Split Level and Split Foyer house plans may contain a finished basement.

Split level with covered parking space

A split level is a home with three or more levels connected by stairs. While not all split-level homes are created with a garage, many do. One of the most common variations in the side split, which places the bedrooms over the garage, while the main living area is located on the other side. This style of home can also include a basement-level recreation room. In some instances, there is also a finished basement level.

Another style of split-level homes is the stacked split level, which has an entrance between the first and second levels. This home often has a low-pitched roof, maximizes available space, and lets rain slide through. This home style is an excellent option for families who want to accommodate a range of lifestyles. For example, if a family is raising kids, a split-level home can accommodate them comfortably and have a separate space for parents to park their vehicles.


ADU plans vary widely, and you’ll probably want to consult with an ADU drafter to create the ideal plan for your ADU. ADU drafters are industry professionals with decades of experience designing and building ADUs. You’ll get a high-quality ADU floor plan design for a low price.

ADU floor plans include essential details like roof layout, wall penetrations, windows and doors, and more. They also have sectional views and detailed callouts. Plan details include a step-by-step assembly guide. You’ll find your ADU’s unique features and specifications in the floor plan design.

Pre-approved plans

While pre-approved ADU floor plan designs save you time and money, they are not necessarily more cost-effective. Ninety percent of the cost of an ADU project goes into the construction process. Most pre-approved plans are not value-engineered and have not been evaluated by a builder to make them as cost-effective as possible. If you need to make some changes, the cost of revising the plans can be as high as $2-4K.

Gunnar Mueller