How do you create an ADU that’s just right for you?

Our architect-designed, adaptable ADU floorplans are a great place to start.
Detached ADUs — also known as backyard cottages or granny flats — generally range from 400–800 square feet. While these aren’t necessarily tiny homes (which are usually less than 400 sf), good design and efficient use of space is key to their livability.

Neil Kelly, in partnership with architect Charles Sax, offers optimized designs ranging from 450-800 square feet that provide an excellent starting point for planning your ADU. These floorplans were designed to maximize livability in a small footprint, while allowing for a high degree of customization of both interior details and exterior architectural style.

Take a look at the examples below to see what’s possible, then schedule a  COMPLIMENTARY DESIGN CONSULTATION with one of our ADU experts to start planning your perfect ADU.


This efficient, compact floor plan provides large kitchen, dining and living room spaces while maintaining an intimate sleeping suite arrangement. The open living/kitchen/dining area features a efficient u-shaped kitchen layout and built-in banquette. Door and window bay treatments enhance the living room and bedroom spaces, and the integrated bedroom/bath area features generous closet space, alcove storage and a private toilet/shower space. A variant of this floor plan trades the dining space for a second bedroom/flex room within the same basic footprint. Craftsman and Contemporary treatments are shown in the examples below.


This open plan delivers the expansive feel of a loft with a highly efficient space plan. The open plan ground floor features a wall to wall kitchen arrangement with the option of a ten foot ceiling height when framed into the attic space above. Coupled with tall windows it’s a reflection of the full height living room area at the opposite end of the house. The second floor loft is a fully integrated suite including sleeping, lounging, bath and study spaces. Large windows opposite the bedroom loft provide generous, dramatic, natural light. Sample renderings below show this floor plan executed in Contemporary and Craftsman styles.


Split level designs are rare in ADU and small house plans. This highly space efficient design features generous room sizes within a compact envelope. The upper level has view capturing windows at the kitchen and eating area plus a space extending balcony/deck off the living room. The dining alcove works well for built-in seating or conventional furniture. Two large bedrooms on separate levels have generous closet space and convenient, adjacent, full bathrooms ideal for guests. High ceiling dimensions emphasize flowing spaciousness. As with other floorplans, this plan can be executed in a number of different architectural styles including Craftsman and Contemporary, as shown below.


This highly efficient floor plan maximizes every square inch of living space. Sliding doors open the home office–study transforming n roomy living/kitchen/dining area into an expansive open floor plan. Closing the doors offers privacy or creates a guest bedroom when needed. Even the bath is compartmented for flexibility. The large, efficient, u-shaped kitchen and breakfast bar/counter layout is comparable with larger houses, and optional built-in seating functions as a dining banquette and cozy alcoved living space. Generous windows fill the interior with light while swing or sliding doors conveniently access outdoor living space. Window locations are ideal for a/c saving cross ventilation.


This two story design takes advantage of every square inch of its area, packing lots of livability into a small footprint. At just 12 feet wide it’s ideal for ADU use and it’s easily expandable for other uses. The downstairs features spacious kitchen/dining and living areas with generous windows and access to outdoor living space. Upstairs there is flexibility for two bedroom sleeping or guest/study uses. In the stairwell tall windows introduce daylight, allow views and provide a/c saving cross ventilation. The airy stairwell creates separation yielding privacy and a feeling of intimacy in each room setting. As with other floor plans, this design may be adapted to a variety of architectural styles.