Restrictions may apply.
- Pet friendly
- On-site Parking
- Studio–3 bed
Flats on First
Your offers
2 offers$150 Cash Back
From Sunny · paid after move-in·
1% price drop
Was $6,579 · saves $80/mo
Your first-month savings
Restrictions may apply
Complete your preferences to get a proper evaluation.
Set PreferencesProperty location
21 Charles Street, Cambridge, MA 02141Featured Units
Pricing and availability
- A10
- 1 bed
- ·1 bath
- ·1101 sqft
$4,817+ mo1Starting atUnit availableUnit 315B
Apply nowAvailable now
13 months lease$4,817 mo
- A7
- 1 bed
- ·1 bath
- ·767 sqft
$3,967+ mo2Starting atUnits available - A2
- 1 bed
- ·1 bath
- ·718 sqft
$4,017+ mo1Starting atUnit availableUnit 404C
Apply nowAvail 11/23/2026
12 months lease$4,017 mo
Amenities
- In unit laundry
- Patio / balcony
- Dishwasher
- Pet friendly
- 24hr maintenance
- Garage
Property details
Flats on First embodies the best of boutique living, combining the luxuries of a modern apartment community with the comforts of a close-knit neighborhood. Come home to a place of sophistication and serenity in East Cambridge.
When each offer lands
At signing
Property special applied
Any move-in special the property is running comes off what you owe them, handled by the property at lease signing.
At move-in
Cash Back unlocked
Once your move-in is confirmed, your Sunny Cash Back offer becomes available in your account.
Within 60 days
Cash Back paid to you
Claim it through Venmo or a Gift Card. Renters have 60 days from move-in to claim — no property approval needed.