Plan record

The 20-Foot House

The 20-Foot House is a prototype ADU plan from Studio Den Den. The public source does not list square footage, bedrooms, or bathrooms, so confirm those fields with the official source before use. It originated in the Massachusetts, USA program. This directory currently shows acceptance in Massachusetts, USA. Source context comes from Massachusetts Executive Office of Housing and Livable Communities, last checked Aug 25, 2026. Use the linked provider, location, and source records to verify current acceptance before relying on the plan.

Prototype Studio Den Den Official source
View official sourceSend correction

Source-backed summary

What public sources list

The 20-Foot House is a prototype ADU plan from Studio Den Den. The public source does not list square footage, bedrooms, or bathrooms, so confirm those fields with the official source before use. It originated in the Massachusetts, USA program. This directory currently shows acceptance in Massachusetts, USA. Source context comes from Massachusetts Executive Office of Housing and Livable Communities, last checked Aug 25, 2026. Use the linked provider, location, and source records to verify current acceptance before relying on the plan.

Provider record
Studio Den Den
Origin program
Massachusetts, USA
Accepted location pages

Details

Plan facts

Plan identifier
Not listed in source
Provider
Studio Den Den
Origin location
Massachusetts, USA
Accepted locations
Status
Prototype
Size
Not listed in source
Bedrooms
Not listed in source
Bathrooms
Not listed in source
ADU type
Not listed in source
Construction type
Not listed in source
Plan fee
$0
Estimated cost
Not listed in source
Last checked
Aug 25, 2026

Plan notes

Notes

Foundation notes
Not listed in source
Utility notes
Not listed in source
Energy notes
Not listed in source
Accessibility notes
Not listed in source
Permit fee notes
Local plan review, permit, and other project fees remain separate.
Cost notes
The free design is a starting point; construction and site-specific professional costs are not included.
Additional notes
State design-challenge winner. Published specifications available to this research did not establish exact size or bedroom count.

Source and evidence

Massachusetts ADU Design Challenge Showcase

Official source
Publisher
Massachusetts Executive Office of Housing and Livable Communities
Source type
Plan catalog
Reliability
Official city/county/state government source (5/5)
Last checked
Aug 25, 2026
Accessed
Aug 25, 2026
Official source

Accepted-in locations

Accepted Locations

1 accepted location