the only issues I could see is the size of the window, and height above finish grade and bedroom floor. bedrooms are required to have at least one Emergency Escape and Rescue Openings. The size of this opening may be larger than existing windows in your bedroom.
Typically when only replacing a window without increasing the width or height of the window you are allowed to replace with the same size window. When enlarging the opening (when other windows do not meet EERO requirement) you would be required to install a window that meets the EERO requirements.
From the 2009 International Residential Code (verify code requirements with your building official):
SECTION R310 EMERGENCY ESCAPE AND RESCUE OPENINGS (link)
R310.1 Emergency escape and rescue required. Basements, habitable attics and every sleeping room shall have at least one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, emergency egress and rescue openings shall be required in each sleeping room. Where emergency escape and rescue openings are provided they shall have a sill height of not more than 44 inches (1118 mm) above the floor. Where a door opening having a threshold below the adjacent ground elevation serves as an emergency escape and rescue opening and is provided with a bulkhead enclosure, the bulkhead enclosure shall comply with Section R310.3. The net clear opening dimensions required by this section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. Emergency escape and rescue openings with a finished sill height below the adjacent ground elevation shall be provided with a window well in accordance with Section R310.2. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.
Exception: Basements used only to house mechanical equipment and not exceeding total floor area of 200 square feet (18.58 m2).
R310.1.1 Minimum opening area. All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.530 m2).
Exception: Grade floor openings shall have a minimum net clear opening of 5 square feet (0.465 m2).
R310.1.2 Minimum opening height. The minimum net clear opening height shall be 24 inches (610 mm).
R310.1.3 Minimum opening width. The minimum net clear opening width shall be 20 inches (508 mm).
R310.1.4 Operational constraints. Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys, tools or special knowledge.
There are additional requirements when window opening is more than 72" above the finish grade or surface.
SECTION R612 EXTERIOR WINDOWS AND DOORS (link)
R612.1 General. This section prescribes performance and construction requirements for exterior windows and doors installed in walls. Windows and doors shall be installed and flashed in accordance with the fenestration manufacturer's written installation instructions. Window and door openings shall be flashed in accordance with Section R703.8. Written installation instructions shall be provided by the fenestration manufacturer for each window or door.
R612.2 Window sills. In dwelling units, where the opening of an operable window is located more than 72 inches (1829 mm) above the finished grade or surface below, the lowest part of the clear opening of the window shall be a minimum of 24 inches (610 mm) above the finished floor of the room in which the window is located. Operable sections of windows shall not permit openings that allow passage of a 4 inch (102 mm) diameter sphere where such openings are located within 24 inches (610 mm) of the finished floor.
1. Windows whose openings will not allow a 4-inch diameter (102 mm) sphere to pass through the opening when the opening is in its largest opened position. 2. Openings that are provided with window fall prevention devices that comply with Section R612.3. 3. Openings that are provided with fall prevention devices that comply with ASTM F 2090. 4. Windows that are provided with opening limiting devices that comply with Section R612.4. R612.3 Window fall prevention devices. Window fall prevention devices and window guards, where provided, shall comply with the requirements of ASTM F 2090.
R612.4 Window opening limiting devices. When required elsewhere in this code, window opening limiting devices shall comply with the provisions of this section. R612.4.1 General requirements. Window opening limiting devices shall be self acting and shall be positioned to prohibit the free passage of a 4-in. (102-mm) diameter rigid sphere through the window opening when the window opening limiting device is installed in accordance with the manufacturer's instructions. R612.4.2 Operation for emergency escape. Window opening limiting devices shall be designed with release mechanisms to allow for emergency escape through the window opening without the need for keys, tools or special knowledge. Window opening limiting devices shall comply with all of the following: 1. Release of the window opening-limiting device shall require no more than 15 pounds (66 N) of force. 2. The window opening limiting device release mechanism shall operate properly in all types of weather. 3. Window opening limiting devices shall have their release mechanisms clearly identified for proper use in an emergency. 4. The window opening limiting device shall not reduce the minimum net clear opening area of the window unit below what is required by Section R310.1.1 of the code.
Sorry to give you so much information, but these are items you should discuss with your building official. Would rather you have the information than do something and the inspector discover a problem later.
Codes from jurisdiction to jurisdiction may vary and since I do not practice in Cali I'm not up on the exact code requirements for your area, but you building department would be .....