What goes up must come down.

That’s the tale of monthly multifamily housing unit starts, which have traditionally shown volatility due to seasonality and the long-term nature of obtaining permitting and approval for apartment communities. Today, the National Association of Home Builders (NAHB) announced an 8.3 percent decline in multifamily starts in October, following an “unsustainably large gain” of 51.3 percent in August.

The good news is that the annualized number of multifamily starts is charging ahead, expected to reach 198,000 units for 2011, a nice surge from 2010’s paltry showing of 112,000 units, according to U.S. Census data analyzed by the NAHB. Leading the way in this year’s return to development were well-known and established apartment developers. Multifamily Executive checked in with the companies that led the MFE Top 50 Builders list at the beginning of the year to get an update on where their starts landed for the year.

Here’s where the biggest builders of multifamily units are likely to stack up in 2011.

#1. Wood Partners
2011 starts:
3,750 units
Increase from 2010: 85%
Atlanta-based Wood Partners finished off 2010 with 2,027 units and pretty much hit its planned goal of 4,300 units for 2011. "We started about 2,000 last year; we’ll do 3,500 to 4,000 this year, and next year we are pretty much back to full production with an estimated 6,500 units," says CEO Ryan Dearborn.

#2. Greystar Real Estate Partners
2011 starts: 
3,617 units
Increase from 2010: 3,600%
After building no new units in 2010, Charleston, S.C.-based Greystar Real Estate Partners got its platform turbo-charged this year, going from zero to more than 3,600 starts in 2011. The numbers surpasses the firm's expectations to break ground on 2,180 units.

#3. Alliance Residential
2011 starts: 
3,550 units
Increase from 2010: 82%
Phoenix-based Alliance Residential pulled 1,952 units out of the ground in 2010 and expected at the start of the year to add another 2,800 units this year. The firm more than bested that goal with an estimated 3,550 starts in 2011, which could increase further by year's end. "We have a pipeline of about 5,000 to 6,000 units, most of which could be closed this year," notes Alliance CFO Jay Hiemenz. "Some may spill over into the first half of next year, but we are looking at a lot more opportunities in markets that we were inactive in and have taken a little bit longer to recover."

#4. AvalonBay Communities
2011 starts:
3,300 units
Increase from 2010: 35%
It's steady-as-she-goes for Arlington, Va.-based REIT AvalonBay Communities. After starting 2,446 apartments in 2010, the firm planned 2,712 new starts in 2011, but it is expected to close out the year with a nice increase to 3,300 starts.

#5. Mill Creek Residential Trust
2011 starts: 
3,100 units
Increase from 2010: 3,100%
Dallas-based Mill Creek Residential Trust showed it hasn't lost any chops after spinning off from former development titan Trammell Crow Residential. The company, which started no new units in 2010, reports breaking ground on 3,100 units this year.

#6. AMLI Residential
2011 starts: 2,777 units
Increase from 2010:
Chicago-based AMLI Residential dialed back its original expectation to begin building some 4,000 units this year and is likely to finish 2011with approximately 2,777 unit starts, still a tremendous leap from the 696 starts the firm completed in 2010. "We are projecting that we will break ground on 3,625 units in 2012," notes company chairman and CEO Greg Mutz.

#7. The Bozzuto Group 
2011 starts:
2,395 units
Increase from 2010: 123%
Based in Greenbelt, Md., regional powerhouse The Bozzuto Group notched 2,395 units, down slightly from an earlier estimated 3,066 multifamily starts for 2011. That's still an increase from the 1,076 units the firm started in 2010. Bozzuto, which builds for its own portfolio as well as for JV and third-party partners, notes that 2012 starts are expected to clock in at 1,719.

#8. Irvine Apartment Communities
2011 starts:
2,200 units
Increase from 2010: 105%
After a relatively robust year in 2010 that saw 1,074 unit starts, Irvine, Calif.-based Irvine Apartment Communities planned approximately 2,404 starts for 2011. While the firm was unable to confirm starts by press time, reports from the Building Industry Association of Orange County put the number of Irvine starts this year at 2,200.

#9. Camden Property Trust
2011 starts:
2,190 units
Increase from 2010: 261%
Houston-based Camden Property Trust will close the year with 2,190 new units under development, a sizable increase from the 607 units the company started in 2010. The REIT expects to start another 1,500 to 2,000 units next year, says Camden CEO Ric Campo.

#10. Gables Residential
2011 starts:
2,065 units
Increase from 2010: 1,620%
Atlanta-based Gables Residential was another firm significantly ramping up activity this year, moving from only 120 new units started in 2010 to 2,065 unit starts this year, just about hitting the firm's initial target estimate of 2,136 units. Gables CEO David Fitch notes, "We are pleased with the development process, particularly in Texas, because the unfortunate drought conditions have resulted in virtually no rain delays for our developments in Houston and Dallas."

[On the Bubble]

#11a The Holland Partner Group
2011 starts: 1,943 units
Increase from 2010: N/A
#11b Equity Residential 
2011 starts:
1,900 units
Increase from 2010: 307%
OK, technically this is a Top 10 list, but Vancouver, Wash. based Holland Partner Group and Chicago-based REIT Equity Residential were so close (and so close to each other) that we felt it fair to list them as runner-ups. After starting 467 units in 2010, Equity set its sights on 2,200 starts for 2011 and looks to finish the year with approximately 1,900 units breaking ground. Holland Partner Group COO of southern california development Thomas Warren notes that his firm intends to best 2011 starts with a heavy slate of 2012 construction on the boards.

Editor’s note:  Think your firm belongs on this list? Email us at cwood@hanleywood.com