garage apartment

8 Things to Consider Before Adding an In-Law Suite

In-law suite additions have been a growing trend in the United States. However, moving in with family is nothing new. That trend began in the US during and after World War II, to help ease some of the housing issues created by the war. Fast forward to 2014, and a record 60.6 million people live with multiple generations under one roof (according to a recent analysis of Census data by the Pew Research Center). Adding space for family members, particularly aging parents, does come with an upfront investment. However, homeowners are able to see the long-term benefits, both financial and familial. 

An in-law suite addition is a private space for in-laws and parents that is attached to or located on the same lot as their grown child’s house. Most in-law suites are custom-built home additions, though basements, converted garages, and stand-alone guest houses are also common. These types of additions are also known as “mother-in-law suites” or “granny apartments.”

Are you thinking about adding a space like this to your home? While we can’t help you with any potential in-law strife, we do have a lot of expertise regarding the actual construction of an in-law suite. Here are eight things to consider:


1.    Cost. Of course the bottom line is important, but the cost is going to vary greatly based upon your needs. Renovating a basement can be a fairly inexpensive option, and building a totally new structure with high end finishes is much more. Ideally, your in-law suite should include everything needed for independent living, such as a separate bedroom, living area, bathroom, and kitchen. Adding all of these elements will put your cost somewhere between $40,000 and $125,000 on average. Because this could add significant value to your house, there are a few different ways to approach it financially, and having a conversation with your home mortgage company would be a good start. 

2.    Local Building Codes. Your typical in-law suite design would include utilities and space needed for a bedroom, bathroom, living room and kitchen. Your local zoning rules will have specific requirements for these additions, and may put restrictions on exactly what type of kitchen you can add because in some areas a full kitchen turns the property into a “rentable space.” We have much experience with these laws and can advise you in this arena if it’s something you are unsure about. 

3.    Septic Systems. If you are on a septic system, you will need to check your septic permit as well. You will want to understand the capacity and location of your existing system, in order to assess whether or not it can handle the addition without any work. 

4.    Location, location, location. Are you wanting the new suite attached to your home or would you prefer that it be designed as a guest house? If attached, consider how the addition will be accessed and how it will affect the flow of your floor plan. If detached, consider ease of access for the resident from the main house as well as from the parking area. Depending on proximity to the house, a detached unit can be connected by a covered walkway.

5.    Independent Power. You may want to consider keeping your addition on its own source of power, heat and air conditioning. This would allow you to shut off the power if the unit is unoccupied for an extended period of time, and it would also allow you to keep track of usage if you or a future homeowner chooses to rent out that space. 

6.    Universal Design. Do your parents have special needs that need to be met, such as wheelchair accessibility or grab bars for the bath? They may not now, but your in-laws probably plan on aging in a place once they move in. Be proactive and make sure their new accommodations are made to age with them. This includes installing pull-out drawers, shower seats, adjustable sinks, and other appropriate amenities. Having a space that is accessible to people with a wide range of abilities may help you in unknown ways down the road. There may be a day when you are very glad you considered this before breaking ground.

7.    Design for the Future. Maybe your parents aren’t ready to move in with you now, but you’d like to keep the option open in the future. Are there other things you could do with the space in the meantime? Are you able to rent it out? Use it as an office or simply a guest room? Could it work as an apartment for your own adult children in a few years? 

8.    Financial Sense. Adding on is a significant investment, but it can also be a wise one. It may be a more affordable option than long-term nursing care, for one thing. In a 2017 report, it was found that the national average cost for semi-private and private nursing home rooms has continued to grow in recent years, with private rooms costing nearly $8,500 a month. It may also increase the value of your house or property. There are many factors to consider when determining the financial viability of the endeavor. 

Retrofitting your home for a loved one is no small task. You will need space and specific design elements. But take note that in-law suites don’t necessarily have to be big in size. And in many cases, the benefits of having parents close by far outweighs the costs. 

At WHC, we have experienced contractors who can help you wade through these issues and more to maximize your space and budget. We have the necessary construction knowledge and a passion for helping our customers reach their specific construction goals. If you have just started thinking about an addition on your house and want to talk with an expert about your space, or you have thought it all out in your head already and want to relay your vision to someone who can make it happen – or somewhere in between – we are here to help. Contact us today for a free estimate!