Cost & Construction

While we love living in the Bay Area, we cannot ignore that we have the second highest cost of construction behind New York.  We want the Inspired In-Law™ Cottage to be a product that can help everyone in our country, however producing prefab units here would make them too expensive for families in most of the US.  That is one of the reasons that we offer pre-designed plan sets that are prepared for onsite construction.

The other reason is that we want to support local economies.  Our model is that you buy the plans from us and then hire a local contractor.  He/she will in turn buy building materials from local lumber yards and design centers.  This helps keep your cost in line with regional prices and feeds the local economy.


How Much Will Your Inspired In-Law Cost?

The average cost of construction in New York is $354 per square foot, San Francisco is $330, Seattle is $280, and Houston is $233, the national average (2015) was $103 per square foot.  In Northern California the construction cost for these In-law Cottages is about $500 a square feet.  Our units are around 500 sq ft so we advise local clients to budget $250,000. But, if you live outside of Northern California you can typically use the national average of $103 x 500 sq ft for a budget of $51,500.  Again, this is why we have chosen to sell plans only so you can build locally based on your regional costs.

You may notice the average cost of construction in San Francisco was listed at $330/sq ft but we used $500/sq ft in our budget.  Here is a sad truth, while building small is beautiful, it is expensive.  There are certain components in houses that are expensive: foundations, mechanical systems, kitchens, and bathrooms.  In larger homes there are rooms like bedrooms and living rooms that have a lot of square footage but don’t have any expensive pieces – this spreads out the higher expenses and brings down the cost of construction per square foot.  However, in our Cottages, all the rooms are packed full of function and so they yield a higher cost per construction square foot.

What Is The Return On Your Investment

The cost of construction can seem overwhelming but let’s look at the numbers:


Mom Moves In

Our clients built the 1 bedroom Bungalow Cottage (link to plan) that is 538 sq ft for Mom.  She sold her house of 30+ years and was able to put $150,000* into the construction costs. The family had to finance $100,000 to cover the construction cost of $250,000.  The adult children were able to take out a home equity line that had a monthly payment of $614. Mom was able to move in and live in a new home for $614 a month versus a senior community which was $4000 a month.  The family could also rent out that unit at market rate for $2400 a month for a profit of $1786. *The money that Mom contributed to the construction on the adult child’s property is a gift to the adult child and is not subject to inheritance tax.


Rental Unit or Space for an Adult Child

Maybe you aren’t ready for Mom moving in but you do have kids in college and fear they can’t move back home because it is too expensive.  You decide to build the 1 bedroom Courtyard Cottage that is 499 sq ft.  You finance all of the construction cost of $250,000.  The loan payment is $1535.  You rent out the unit for $2400 and make a profit of $864 a month.  When your child comes home, after college, they can live in the unit for a below market rate of $1535 and cover the loan payment.  Then, when your house becomes more maintenance and cleaning that you want, you can move into the Cottage, which is designed for aging-in-place and rent out the main house.  This way you stay in your neighborhood, in your garden, and have a revenue source!



The Numbers Look Good, But Am I Zoned For An In-Law?

Your town or city will have a planning/zoning office which will help you determine if you can have an In-law in your back yard.  We have compiled a list of Inspired In-law Planning Questions for you to review with your local Planning office.  This process can be somewhat overwhelming.  If you would us like to do the code research for you we offer that service for a fee of $200.  What we need is your address, and a few pictures of your back yard that show any features that could impact the construction, emailed to

If it turns out you are not zoned to have an In-Law, consider hiring a local architect to explore an addition or basement remodel to get you the extra space. We recommend the American Institute of Architects to find an Architect near you.

If you are in the Bay Area, please give us a call at Larson Shores.      

Finally, How Much Do The Plans Cost?

The base price for the plans is $2500.  This includes floor plans, elevations, sections, interior elevations, window, door, finish, and plumbing schedules, and electrical plans.

The drawings do not include engineering of the foundation as your yard will have particular conditions and soil types.

To file your permit you will need a site plan showing the cottage located in your yard. We can work with you at an hourly rate to complete your site plan, or you can work with your contractor or local engineer to complete the package.

If you like the plans, but something isn’t quite right or you want to adjust something, we can work with you at an hourly rate to create a custom unit just for you!

Ready to go?  Reach out to to get started!