Huge FPS drops in menus and personal condo

So after spending most of last night playing this great game and having a lot of fun, I just wanted to bring forward a couple of issues with the game I had, mostly that I could barely work any menu in the game due to the high amount of delay and FPS dropping I received whenever using any menu, as well as the constant dropping of my FPS when in my own personal Condo. The rest of the game works perfectly for me - including going to other peoples condos and using everything in the main plaza, but it is just the big drops when using my own condo or any menu that makes it a bit of a struggle at the moment.

Is there anything I can do to try to fix this? I have already reduced a lot of/if not all the graphical options and nothing seemed to fix the issue.

Including system specs will help determine what the issue is.

edit: if you have got a lower spec computer, you can try running the game in Dx10 instead of 11.

Oh, whoops! Should have added that in the first post. Specs are:

Processor

Intel® Core™ i7-4790 CPU @ 3.60GHz

RAM

16 GB

Video Card

NVIDIA GeForce GTX 745

Chipset - GeForce GTX 745

Dedicated Memory - 4.0 GB

Total Memory - 12 GB

151GB free space on HDD being used

Running Windows 8.1 OS

I should also note that these issues have arisen in both the Dx10 and Dx11 version of the game.