Cash and jewellery were stolen during a break in at a Castle Hill home on Monday.
Thieves forced their way into a Glenwood Way house with a hand-tool between 7am and 6pm.
Once inside the thieves ransacked the house and took several items before leaving through a rear sliding door they entered in.
Another break in happened hours later at display home in Rouse Hill.
Police said a crowbar was used to force open a door at a Sanctuary Drive house.
Thieves ransacked the office area and took a laptop computer, fire extinguisher, garbage bin and a construction hat.