How much does it cost to build an in-law suite above a garage?

Author: Ramon Lesch  |  Last update: Tuesday, October 21, 2025

Above-Garage Suite Adding a suite above your garage involves reinforcing the existing structure to support the new living space. This includes strengthening the walls and adding structural elements to handle the added weight. Typically, the cost to build up a garage with an in-law suite ranges from $50,000 to $100,000.

How much to build an inlaw suite?

The cost of building an in-law suite can vary widely depending on factors such as size, location, materials, and local labor costs. On average, it can range from $50,000 to $250,000 or more.

How much does it cost to build an apartment on top of a garage?

As a rough estimate, basic apartment garage plans can cost anywhere from $50,000 to $100,000 or more, depending on the location and cost of materials and labor. Larger or more luxurious garage apartments can cost well over $100,000 or even up to $500,000 or more.

How much does it cost to convert a garage to an inlaw suite?

In-Law Suite

Converting a garage into a full in-law or guest suite—or a guest house in the case of a detached garage—costs $20,000 to $50,000 on average. At the lower end of the range, a basic conversion will include insulation, drywall, flooring, and a bathroom.

Does adding an inlaw suite increase home value?

On average, an in-law suite can increase your home's value by 20% to 30%, depending on where you live and the quality of the addition.

Garage Apartments & How Much They Cost

What is the average size of an in-law suite?

On average, these suites range from 500 to 800 square feet, providing sufficient space for a comfortable, functional home within a home.

How much does it cost to add a mother in-law suite above a garage?

Converting a Garage, Basement, or Attic

Converting a garage or basement is often ideal for an in-law suite since it already has framing and foundation. Expect to spend $20,000 to $60,000 to convert a garage and $10,000 to $30,000 to finish a basement.

Is an inlaw suite a good investment?

Overall, building an in-law suite can be a smart investment for homeowners who weigh the costs and benefits and plan for the long-term. With the potential for rental income and increased property value, it can provide a comfortable living space for family members while also generating additional income.

How much is a 2 car garage with apartment above cost?

According to our prices, a modular single-car garage with an apartment ranges from $17,125 to $36,845 based on size and other additional features. You will pay approximately $38,658 to $59,018 for a two-car garage with an apartment space.

Do I need permission to convert my garage?

Planning permission for a garage conversion is not necessary in many cases, although it is always best to double check with your local authority first. Most integral garage conversions fall under Permitted Development which means there is no need to make a planning application.

What is the most expensive part of building a garage?

The most expensive part of building a garage is typically the labor and materials. Skilled labor, including tasks such as framing, roofing, and installing electrical systems, can significantly drive up costs.

What is an apartment above a garage called?

Above Garage Apartments Explained

ADUs have exploded in popularity in just the last few years thanks to recent legislation changes in cities all throughout the country. California, especially, has made history with its ultra-lax statewide regulations that have made building an ADU easier than ever.

What is an in-law suite also called?

A secondary suite (also known as a accessory dwelling unit (ADU), in-law apartment, granny flat, granny annex or garden suite) is a self-contained apartment, cottage, or small residential unit that is located on a property that has a separate main, single-family home, duplex, or other residential unit.

How much does it cost to build a 500 sq ft casita?

Custom Building a Casita

If you consider the average of 150 – $200 per square foot, the starting cost for a casita around 500 square feet is $75,000. Again, this depends on the quality of your materials, the size of the house, and the amenities.

Is the mother in-law suite a tax deduction?

There may be tax credits for having an ADU or in-law suite. For instance, if you're paying for more than half of your relative's support, you may be able to claim them as a dependent. You may also qualify for a home office tax deduction if that's the in-law suite's primary use.

Can I build an apartment on top of my garage?

If you're building a completely new loft above your garage, you'll need to ensure that basic utilities are in order. This will most likely be the most expensive part of building the apartment above your garage. An attached garage will have a little bit of an advantage when it comes to electric wiring and plumbing.

Do garage apartments add value?

The value added by a garage apartment can be affected by various factors, including: Size: Generally, larger garage apartments can add more value than smaller ones. Quality of construction: A well-built and high-quality garage apartment can add more value than one that needs to be better constructed.

How much does it cost to add an inlaw suite?

The average cost to build an in-law suite addition ranges from $25,000 to $265,000, with most homeowners spending around $82,750. Whether you're looking to provide a comfortable space for family members or generate rental income, adding an in-law suite can be a valuable investment.

How many square feet is the average mother-in-law suite?

How many square feet is a typical mother-in-law suite? Mother-in-law suites can vary in size but are typically about 500 square feet.

How big should an in-law suite be?

Approximately 500 to 700 square feet is a good size for an in-law apartment or addition.

Can you rent out a mother in-law suite?

If you know the unit will sit vacant for a while, an in-law unit can be turned into a more traditional rental, with long-term monthly or even yearly leases.

How much is a 2 car garage with an apartment on top?

The average cost to build a garage with an apartment is $200 to $350 per square foot or $80,000 to $300,000 total, depending on the size. A 24 x 24 garage with an apartment costs $115,000 to $200,000. Adding a living space to a prefab detached garage costs less than a custom build.

How much does it cost to build a 2 bedroom apartment?

The average price to build an apartment building is $270 per square foot but can range between $90 - $430 per square foot. If a 2-bedroom apartment is typically around 800 square feet, then the average cost is around $216,000.

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