using lager yeast in an ale.

I want to make a clone of new Belgium 1554 enlightened black ale. It is an ale fermented with lager yeast at ale temps. This will be only my second batch and I haven't even tried my first batch yet lol. Austin homebrew supply.com has a clone recipe kit I'm thinking of ordering but I'm nervous about this whole lager yeast at ale temps. And how much longer will it take to ferment than regular ale would? Thanks in advance for any help!

If you don't have a fridge where you can lager it, you could probably sub it out for a clean ale yeast like 1056 and still get a great result.

The link to the recipe is http://www.austinhomebrew.com/product_info.php?cPath=178_452_43_322&products_id=1735
And the recipe is Extract: 8 lb Liquid Malt Extract, 1.69 lb Specialty Grains

Yeast- wlp838 white labs southern German lager

Check out brewing tv episode 53. They talk about using either the Bavarian lager strain or a west coast lager strain at ale temps. They do a side by side taste test with an ale yeast with good results.