In the UK, the ideal size for a bedroom can vary depending on the type of bedroom and the overall size of the house or apartment. However, there are some general guidelines:

Single Bedroom: A standard single bedroom typically needs to be at least 7 square meters (about 75 square feet). This size should accommodate a single bed and some basic furniture like a bedside table and a wardrobe.

Double Bedroom: For a double bedroom, the recommended minimum size is about 10.5 square meters (approximately 113 square feet). This allows for a double bed and some additional furniture.

Master Bedroom: A master bedroom, especially if it includes an en-suite bathroom, is usually larger. The ideal size can be around 13 square meters (140 square feet) or more.

UK Building Regulations: It’s important to note that the UK building regulations set out minimum space standards, especially for newly built homes. These regulations might specify minimum room sizes to ensure comfort and functionality.

Remember, these sizes are general recommendations and can vary based on individual needs, the layout of the house, and personal preferences. In urban areas where space is at a premium, bedrooms might be smaller than these ideal sizes.