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ADU Glossary & Terms

Updated: Jan 26, 2022

Detached Accessory Dwelling Unit:

Building a detached or semi-detached dwelling, familiarly known as an accessory dwelling unit, or ADU, is something that many people dream of. However, before starting on your dream of building an accessory dwelling, there are some terms, outlined below, that you should comprehend.

Accessory Dwelling Unit:

This unit is defined as a detached or semi-detached structure that is built on the same building lot as the owner's primary residence. One of these spaces is designed to have a kitchen and working plumbing fixtures.

Detached A.D.U:

A detached kind of his building shares no walls with a primary structure. It is perfectly self contained and can function as a tiny home.

Attached A.D.U:

An attached one of these buildings does share adjacent walls with a primary structure. It can abut a load bearing wall or be built into the garage.

Junior A.D.U:

A junior one of these sorts of dwellings is exactly the same as a full size one, except that it is smaller. Whereas a full size dwelling can be at maximum 1200 square feet, one of the junior variety has a maximum of just 500 square feet.


As setback in an ADU or JADU is an issue that you may face when it comes time to build and ADU. Space is a common one, though many people find they get some space back when they choose an attached version than fully detached.

Floor Area Ratio:

This is the ratio of the full square footage of your structure to the total square footage of the property on which it is standing. For example, a small dwelling such as a junior accessory dwelling unit will take a small percentage of the total property available to you.

Architectural Compatibility:

This is a fancy way of saying that if your primary residence looks a certain way, so must your small dwelling. They must complement, or be compatible with each other. In many jurisdictions this is a requirement for build and ADU. NEO Builders prides itself on excelling at designing dwellings and JADU that will blend in seamlessly.

Lot Coverage Definition:

When you build a dwelling, your town needs to make sure that it fits in the parameters of your lot of property. Finding the percentage of lot coverage helps them do this. Lot coverage is basically how much of your property is covered by a structure.

Lot Coverage Equation:

Your property has a maximum lot coverage amount. This is how much of the land is allowed to be covered by permanent structures. This is determined by dividing how much of it is covered by structures by how much land is currently available.

Parking Requirements:

Starting just this year, you do not need t have parking with your accessory dwelling. However, this is only if they are attached to your primary residence or another detached structure in which to store vehicles. NEO Builders can help you decide on a design that is just right for you.

Discretionary Review (DR):

A discretionary review is a common term for a commission consideration of your building plans. This is the first step in being allowed to start construction on your dwelling.

Ministerial Review (MR):

If your plans for building a dwelling are compliant with the local zoning statutes, then this sort of review that can give the go ahead on your project offers a streamlined approach and is much faster. This form of review is becoming increasingly popular in California.

Cash-Out Refinancing:

If you are in good standing with the bank through which you have a primary mortgage, cash out refinancing can be used to add on to the initial amount and get you the necessary funds.


Doing an appraisal of your accessory dwelling or Junior Accessory Dwelling Unit is helpful when you need to get the initial financing for your project, or you are in the process of selling your home. While having a structure on your property can add to its value, be aware that it can only count upon completion.

Home Assessment:

An assessment of your primary residence, including small dwellings, will be used by a third party organization to calculate the property taxes that you owe. While dwellings on your property can increase the value, they can also cause your taxes to go up.

Property Tax:

Property taxes are a fee every homeowner must pay to the government for upkeep of their property. Property taxes are often paid every year, several times a year at regular intervals, or as part of their mortgage payment every month. The professionals at NEO Builders can help you navigate this occasionally confusing concept.

Local Neighborhoods for ADUs and Garage Conversions



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