Jennifer Aniston and fiance Justin Theroux are busy planning their dream wedding, but the couple also has another particularly time-consuming project on their hands — renovating the massive Beverly Hills mansion they share together.

The sprawling home includes four bedrooms and seven bathrooms on a piece of property that measures approximately three acres. The house in its current form is about  8,500 square feet, but Aniston and Theroux's expansion plan will grow that number to a whopping 12,695 square feet.

The project has been ongoing for quite a while, and a new report from E! News explains what is taking so long - the couple has been struggling to acquire the construction permits they need for the massive overhaul of the property.

"Contractors have asked the city of Los Angeles' permission-via two permit applications, so far-to expand the master bedroom, including the addition of a deck with a trellis; add a cantilever roof eave; remove a different trellis and install roof covers outside the living room, dining room and library, according to public records," E! reported. "Aniston is also installing an elaborate water feature with a recessed black lava veneer around newly constructed concrete stairs that flows into a pond that's less than 18 inches deep."

The home, which was formerly occupied by legendary record producer Quincy Jones, features many amenities, including a pool, massive motor court, unobstructed views of the city and the Pacific Ocean, a vineyard, a guest house and several patios perfect for parties.

CLICK HERE to check out photos from inside Jennifer Aniston and Justin Theroux's enormous Beverly Hills mansion.

The couple may soon need some of the home's extra room. A new report from In Touch claims that Aniston is pregnant and the couple is over the moon with excitement.

"Justin's telling his friends. Jen's really excited, too, but she's concerned because of her age and because it's early. She wants to make sure everything's okay and is focusing on her health right now," a source said.