Accessory Dwelling Unit Design/Build Services by Neil Kelly
Neil Kelly helps Northwest homeowners make the most of their properties by designing and building high-quality accessory dwelling units (ADUs). Also known as backyard cottages, in-law apartments, or granny flats, ADUs are separate residential living spaces constructed on the property of a single-family home. Whether the goal is to accommodate guests, house family members, or generate rental income, an ADU is a smart way to leverage available space.
Neil Kelly offers expertise across several types of ADU projects, including:
- New construction of a detached ADU or freestanding backyard cottage
- Garage conversion or expansion of an existing secondary structure into an ADU
- Conversion of interior spaces — such as a basement or attic — within the main home
- Addition of an attached ADU to the primary residence
While building a small backyard cottage may seem straightforward, local regulations can be complex. Careful planning and efficient design are essential to ensuring comfort and livability within a compact space. Neil Kelly's design/build team has the knowledge and experience to navigate all requirements, options, and possibilities to deliver an ADU suited to the property, the budget, and the intended use.
Custom ADU Design and Construction
For homeowners considering an attached ADU, a converted space, or a one-of-a-kind freestanding cottage, Neil Kelly brings the same level of expertise, craftsmanship, and environmental awareness to ADU development that they apply to remodeling and custom homebuilding. Their approach strikes the right balance between design vision and functionality, technology and nature — all with uncompromising construction quality.
A notable example of their work is a Southeast Portland ADU that combines contemporary Northwest design with industrial elements, creating a light and spacious feel within a compact footprint. Designed for the short-term rental market, the team selected materials and finishes that are durable and easy to maintain, while also prioritizing energy efficiency and solar power.
Frequently Asked Questions About Building an ADU
What types of ADUs does Neil Kelly build?
Neil Kelly constructs a wide variety of accessory dwelling units, including attached ADUs, detached or freestanding structures, garage conversions, basement conversions, attic conversions, and home additions.
What must an ADU include?
Requirements vary by location, but typically an ADU must include sleeping, kitchen, and bathroom facilities, at least one operable window or exterior door for emergency egress, heating controls separate from the primary dwelling, and connections to water and sewer services.
How much does an ADU cost?
Costs depend on the type of ADU, the existing property, local building regulations, and other factors. Speaking with one of Neil Kelly's design consultants is the best way to get accurate project-specific estimates.
Should an ADU be custom designed or can pre-approved plans be used?
Custom-designed ADUs generally offer greater functionality and resale value. However, some Oregon municipalities offer pre-approved plan sets to streamline permitting. Neil Kelly's design consultants can help identify the right starting point based on project goals.
What permits are required to build an ADU?
In most cases, a building permit is required for new ADU construction or conversions of garages, attics, or other spaces. Electrical, plumbing, or mechanical permits may also be needed depending on the scope of the project. Neil Kelly's team can help navigate local permitting requirements from start to finish.
