Which is bigger, the Six Sixty Duo or the Seven Forty-Nine?

The Seven Forty-Nine is bigger at 749 sq ft, compared to 660 sq ft for the Six Sixty Duo.

Which costs less, the Six Sixty Duo or the Seven Forty-Nine?

The Six Sixty Duo is the lower-priced option at $339,000, which includes a permitting budget along with plans, foundation, and delivery, compared to $369,000 for the Seven Forty-Nine. Exact permit costs are set by your city or county and confirmed in your feasibility study.

Which one delivers faster, the Six Sixty Duo or the Seven Forty-Nine?

The Six Sixty Duo has the shorter typical timeline at 5 months, compared to 5–6 months for the Seven Forty-Nine.

When should I choose the Six Sixty Duo over the Seven Forty-Nine?

Choose the Six Sixty Duo if you want a true two bedroom unit at the lowest possible price on a smaller lot.

When should I choose the Seven Forty-Nine over the Six Sixty Duo?

Choose the Seven Forty-Nine if you want more square footage, an L-shaped layout with better privacy, and space suited for two-household living or premium rentals.

Two Bedroom ADU Comparison

Six Sixty Duo vs Seven Forty-Nine

The Six Sixty Duo and the Seven Forty-Nine are both two bedroom, one bathroom ADUs, but they're built for different goals. The Six Sixty Duo fits two bedrooms into 660 square feet starting at $339,000, while the Seven Forty-Nine opens up to 749 square feet starting at $369,000. Both build fast, the Six Sixty Duo in about 5 months and the Seven Forty-Nine in 5 to 6 months.

At a Glance

	Six Sixty Duo	Seven Forty-Nine
Size	660 sq ft	749 sq ft
Bed / Bath	2 Bed / 1 Bath	2 Bed / 1 Bath
All-Inclusive Price*	$339,000	$369,000
Typical Delivery	5 months	5–6 months
Footprint Shape	Rectangular	L-shaped
Best For	Maximum rental income, small families, roommates.	Two-household living, parents who want privacy, premium rentals.

*Includes a permitting budget, not final permit costs. Permits and property-specific site work (septic, retaining walls, etc.) vary by property and are confirmed in your feasibility study. Every price also includes plans, foundation, the factory build, delivery, utility hookups, appliances, and final inspection.

Where the Six Sixty Duo Wins

Pick the Six Sixty Duo for this.

● Lowest price of the two at $339,000
● Compact 660 square foot rectangle layout, easier fit on small lots
● Best for maximizing rental income, small families, and roommates

Where the Seven Forty-Nine Wins

Pick the Seven Forty-Nine for this.

● Larger at 749 square feet with an L-shaped layout
● More separation between bedrooms, good for two households under one roof
● Built for parents who want privacy and premium rental appeal, from $369,000

The Honest Verdict

How to actually decide.

If you want the most rental income or living space per dollar on a small lot, the Six Sixty Duo is the smarter buy. If you want real separation between bedrooms and a layout built for two households sharing the space, the Seven Forty-Nine earns its higher price.

Choose the Six Sixty Duo if: Choose the Six Sixty Duo if you want a true two bedroom unit at the lowest possible price on a smaller lot.
Choose the Seven Forty-Nine if: Choose the Seven Forty-Nine if you want more square footage, an L-shaped layout with better privacy, and space suited for two-household living or premium rentals.

BBBA+Google 4.9CSLB#1047146MFG#1595931Yelp5.0

Compare More

Other model comparisons.

Small Lots, Entry Models Four Fifty vs The 405 Studio Efficiency or a Real Bedroom? → Studio vs One Bedroom Four Fifty vs Five Five Five A Studio to Start, or a Real Bedroom? → One Bedroom, Two Sizes The 405 vs Five Five Five A Cozy Bedroom or Room to Breathe? → One Bed, One Bath, Two Sizes Five Five Five vs Six Sixty More Room to Breathe, or the All-Rounder Everyone Picks? → Same Footprint, One Bed or Two Six Sixty vs Six Sixty Duo One Bedroom or Two, Same 660 Square Feet? → Two Bedrooms, One Bath, Two Scales Seven Forty-Nine vs Eight Eighty-Five Duo More Privacy or More Room to Grow? →

Form not loading? Open it directly →

Still Deciding?

See which one actually fits your lot: the Six Sixty Duo or the Seven Forty-Nine.

Every property is different. Tell us your lot size, budget, and what you need the space for, and a real person on our team will tell you which model works, plus your exact price with permitting and site work factored in.

A shortlist of which models actually fit your lot
Honest flags on anything property-specific, like slope or septic
A clear next step, whether that is a factory tour or a feasibility study
No pressure, and no obligation

Once you submit, a real person on our team reviews your property and follows up within 1 to 2 business days to book your free 30-minute call. No call center, no drip campaign, just a conversation.

After we review your property, we'll invite you out to the factory, or send a member of our team to you, whichever fits your schedule better.

Building more than one? If you're a real estate developer or investor planning multiple units, let us know in the form. We offer better pricing at volume.

We respect your inbox and your phone. Message and data rates may apply, message frequency varies, reply STOP to opt out or HELP for help. See our Privacy Policy and Terms & Conditions.