How can I comply with Part B building regs for my project?

Compliance with building regulations, specifically Part B (Fire Safety), is crucial to ensure the safety of occupants in a building. In relation to travel distances, the requirements you mentioned (18m in one direction and 45m in two directions) typically refer to the maximum permissible distances from any point within a building to a final exit. These distances are intended to ensure that occupants can evacuate safely within a reasonable time in the event of a fire or emergency. If your project does not meet these travel distance requirements to the final exit, but you have created a fire compartment area within the building, it's important to consider the following: Compartmentation: Fire compartments are designed to limit the spread of fire and smoke, providing a safe area for occupants to remain in until they can safely evacuate or be rescued. Compartment walls, floors, and doors should have adequate fire resistance to prevent fire and smoke from spreading beyond the compartment. Fire safety measures: Fire safety measures, such as appropriate fire detection and alarm systems, fire suppression systems, and emergency lighting, should be installed in the building to ensure early warning, control, and safe evacuation in the event of a fire. Means of escape: While a fire compartment area can provide temporary safety, it's important to ensure that occupants have a clear and unobstructed means of escape from the compartment to a final exit. This may involve providing sufficient and appropriately sized escape routes, ensuring adequate signage and wayfinding, and maintaining clear access to the final exits.

This cannot be answered without reviewing a plan of the situation as there is nuance which may make it acceptable or unacceptable. An architect would be able to give advice in the first instance, but it may also need the input of a specialist Fire Engineer as well.

Paragraph 1.1 in Volume 1 of Approved Document B recommends all new dwellinghouses should be provided with smoke alarms in accordance with the BS 5839-6 to at least a Grade D2 Category LD3 standard. However, table 1 of BS 5839-6:2019 recommends Grade D1 Category LD2? For the purposes of Part B of the Building Regulations a Grade D2 Category LD3 system is considered to be adequate. Therefore, as a minimum, the system itself should be designed and installed in accordance with the guidance for a Grade D2 LD3 systems in BS 5839-6:2019.

Employ a professional to advise you. You don't have any/the correct understanding of what you're working on and this is not the platform to be asking technical compliance questions especially concerning fire.

Your question pertains to the UK Building Regulations, specifically Part B, which deals with fire safety. When you refer to the 18m one direction and 45m two directions travel distances, you're referencing common criteria for escape routes in the event of a fire, depending on the layout and nature of the building. The purpose of these distances is to ensure that occupants have a safe means of escape, which typically means reaching a place of safety before the conditions become life-threatening. However, the intricacies of how these distances are applied and interpreted can vary depending on various factors like the building type, use, and specific design. Generally, the travel distance is the actual distance that a person has to travel to reach a place of safety. It's important to understand how the term "place of safety" is defined in your particular context. While a fire compartment can act as a temporary safe area to prevent the spread of fire and smoke, it doesn't necessarily mean it's a "final place of safety." Typically, a place of safety is outside the building or a protected stairway leading outside, but again, this can vary based on context.