ECHO units can be a fairly affordable housing option when compared to, say, a few years in an assisted-living center. A new, basic 500-square-foot unit might go for $25,000, while a bigger, higher-end carriage house can cost as much as $100,000. Expect to pay extra to pour a foundation and set up the utility connections.
In some places, the cost can be offset slightly by a state "caregiver" tax credit, available to adults who provide ongoing care to their aging parent. (In California, for example, this is $500 per year per parent.) Depending on your area's zoning laws, ECHO housing units can also be rented out and used to generate monthly income after a family member moves out.
ECHOs can be bought or leased, new or used. You may be able to find a used unit through your local classifieds or an online buy-sell resource like Craigslist.org. Search for phrases like "modular home," "manufactured home," "carriage house," and "mobile home."

Great invention. It's another selection available at a time in life when options are limited.
Are there any government grants or monies to help with building or remodeling to provide home/shelter for disabled parent?
We found out how a backyard cottage could be part of an aging in place when we designed one for a client that allowed him to care for his aging mother and for her to be a bigger part of his family. Increasingly, backyard cottages, unlike ECHO, are not temporary trailers but are traditionally built homes that may incorporate universal design features and monitoring to facilitate elder living. Enlightened cities like Seattle, Portland and Vancouver, BC allow backyard cottages to be built in residential zones with some restrictions. We are happy to continue designing backyard cottages because we think they offer a valuable option for multi-generational living.
good information.
A few months ago three of us decided to start a business to help families with housing for aging family members. We named our company Sidekick Homes and we can be found at www.sidekickhomes.com. Unknowingly we were providing Echo Housing. Our services include literally everything from an expression of need by a family to welcoming the person into their new place of residence close to the family. Essentially we are a concierge service who will take care of all the details of design, construction and installation of the new home in the garden. Mike
This is a very intriguing idea. Years ago we tried to get my husband's parents to move to our city to be closer to us and our children. But we hadn't thought of building them a small house in our backyard. What a great way to provide for your parents but still be independent - for both sides