AARP Home » Home & Family » Your Home »Prefab 'In-law' Cottag...

Prefab 'In-law' Cottages Mix High-tech Features, Comfort

New freestanding modular home additions aim to provide the right kind of space for aging in place.

by: Elaine Petrowski, from: AARP

O’Connor believes that ADUs can be a viable alternative, “but not without consideration. Make the choice with thoughtful purpose, and don’t plan to just park somebody there. Plan how to help her stay engaged in the wider community.

“And don’t forget that at-home health care always takes a toll on the caregiver. Again, plan ahead for support and relief from care duties,” O’Connor says.

ADU Costs vs. Conventional Additions

Are ADUs less expensive than comparable home additions built in the conventional way? If you’re able to put an ADU on your property, the answer is probably yes.

Since prefab additions are relatively new, cost data for direct comparison with conventional home additions aren’t available. Instead, we have to work with comparisons between new prefab and homes built on site. The consensus among cost estimators is that prefab costs less than stick. How much less? CostHelper.com — an online building cost reference tool — says that “modular construction costs 5 to 25 percent less than traditional homes built on site.”

Construction costs vary widely by region and local market conditions. Remodeling is generally more expensive on a square-foot basis than new

Clearing the Way for an ADU

Before deciding that an accessory dwelling unit (ADU) is your best bet for your home care needs, you’ll need to do some homework to learn about possible obstacles and associated potential costs:

Talk to local building and zoning code officials to be sure that regulations, such as the permissible percentage of a lot that may be covered by a structure , allow you to place either a permanent or a temporary ADU on your property.

Contact your local power, sewer or water agency to obtain clearance.

Evaluate access to your property. Does street configuration or topography limit access?

Check on the septic system. If your current septic system accommodates a four-bedroom home, adding an ADU with an additional kitchen and bath may mean your septic system will no longer comply with regulations and will need updating.

See if there are any restrictions on your lot due to covenants or a homeowner association agreement.

Consider the impact of installing an ADU on existing mature trees and landscaping.

Talk to a remodeling contractor about the cost of connecting. Investigate any regulations regarding tying into the existing building systems, such as electrical, plumbing, heating, cooling and fire alarms.

Check about other possible permit requirements. If your home is in or near wetlands, in a historic district, adjacent to state or local parks or watershed management areas, you may need to file for additional permissions.

While most of these situations do not disqualify a property owner from adding an ADU, you may have to file for a variance or exemption from local regulations. That application process will likely add many months to a building schedule.