Number of Storeys

Why it matters for underwriting

The number of storeys shapes how smoke, heat and fire gases move through a building and how quickly occupants can evacuate and firefighters can gain access. Multi-storey buildings, especially those tall enough to be classed as high-rise, rely far more heavily on engineered smoke and heat venting, protected stairwells and vertical compartmentation than single-storey buildings, because external firefighting from ground level becomes impossible above a certain height. Underwriters use storey count as an early indicator of the fire protection engineering needed and of the evacuation and business interruption exposure at the location.

Capturing the attribute and evidence

Proposal forms ask for the number of storeys above and below ground and the overall building height, since local high-rise thresholds are usually defined in metres rather than storey count alone. Architectural drawings, the building permit and the fire safety concept document confirm the declared figures; a risk engineering survey is typically requested for taller buildings to verify that vertical fire protection measures match the actual height.

Effect on coverage, premium and conditions

Low-rise buildings with straightforward evacuation routes generally attract standard terms. As storey count and height increase, insurers more often apply premium loadings, require documented smoke and heat venting or pressurised stairwell systems as a condition of cover, and may impose sublimits or exclusions where a high-rise building lacks an adequate fire safety concept or basement levels present accumulation concerns.

Mitigation measures

For taller buildings, insurers typically recommend engineered smoke and heat venting, protected and pressurised escape stairwells, vertical compartmentation between storeys, and a documented, regularly tested evacuation concept appropriate to the building’s height.