The moment many of us have been waiting for has arrived. Westfield Development has just officially announced that Xcel Energy has agreed to lease approximately 350,000 square feet of 1800 Larimer’s total 500,000 square feet.

Site prep work has been taking place at the 18th and Larimer location on Block 066 for several months now, but until today Westfield had not made any official acknowledgement that construction had started. With today’s announcement, it will be full-steam ahead for 1800 Larimer toward its 2010 completion.

Here’s the full press release issued moments ago by Westfield: 1800 Larimer Press Release and in case you haven’t seen the rendering lately, here’s what the 22-story tower will look like:

1800 Larimer has been pre-certified as LEED Platinum and will be one of the city’s most green/energy-efficient buildings.

We now officially have a 22-story building under construction to join the Four Seasons, Spire, and our other high-rises in the works.

Congratulations, Westfield!