5 Ways to Impove Dream Home Decorator

One of the worst disappointments to me was that, well... your clients or the game have absolutely no idea what "a renovation" is:

You are called to make a kitchen renovation for the Pancakes. 

Bob says he loooooves gardening.

Eliza says she hates cooking with passion.

They both reveal they really enjoy playing the guitar.

You send them away, take the biggest hammer you can, demolish the entire corner of the house and remove the kitchen altogether.

With the freed money, you give two planter boxes for Bob and ten luxurious guitars to the couple.

They now have no kitchen.

Eliza's bedroom is about to crumble to the ground where it's hanging over Bob's planter boxes where the kitchen once was.

They return to see their renovated kitchen, cry with joy and pay you extra.

The game does not keep any kind of track about what "a kitchen" or "a nursery" or "a level renovation" is, you can just demolish the house and put gnomes in a row. 
The likes and dislikes of the Sims in households are also a massive issue (I have written about this in length in the past) AND may directly interfere with the renovation you are asked to do.
"Renovate my kitchen, I hate cooking." "I want to take care of my baby while mixing drinks." "I need a garden and BOY do I hate gardening." "My office needs a makeover. I am a serious man, however, and despise comedy. Fun things can be done at a desk, on a computer. Thus, do not give me a computer, or desk, or fun."