Approved_Document_O_Flashcards
What is the purpose of Approved Document O?
It provides guidance on how to comply with Part O of the Building Regulations, which addresses overheating mitigation in residential buildings.
When did Approved Document O come into effect?
It took effect on 15 June 2022 for use in England.
What types of buildings does Approved Document O apply to?
New residential buildings, including dwellinghouses, flats, residential institutions, and student accommodations.
What are the two main methods to demonstrate compliance with overheating mitigation?
The simplified method and the dynamic thermal modelling method.
How does Approved Document O interact with other Building Regulations?
It interacts with Parts B (fire safety), F (ventilation), J (combustion appliances), L (energy efficiency), K (protection from falling), M (accessibility), and Q (security).
What is the main objective of Part O in the Building Regulations?
To ensure residential buildings are designed to mitigate overheating and provide a comfortable indoor environment.
Who is responsible for compliance with Approved Document O?
Designers, builders, installers, and building owners.
What happens if the Building Regulations are contravened?
The local authority may prosecute those responsible in the magistrates’ court.
How does Approved Document O ensure compliance?
By providing guidance on limiting solar gains and ensuring effective removal of excess heat.
Where can more details on the building regulatory system be found?
In the ‘Manual to the Building Regulations’ available on gov.uk.
What is the purpose of the simplified method in Approved Document O?
It provides an easy way to demonstrate compliance with overheating mitigation requirements.
How is a building’s overheating risk category determined in the simplified method?
Based on location (moderate or high risk) and whether it has cross-ventilation.
What is the main goal of limiting solar gains?
To prevent excessive heat buildup inside residential buildings during summer.
What is the role of cross-ventilation in overheating mitigation?
Cross-ventilation helps remove excess heat more effectively by allowing air to flow through opposite façades.
Which areas are classified as high-risk for overheating?
Urban and suburban areas in London and some parts of Manchester, as detailed in Appendix C.
How does the simplified method limit overheating risk?
By categorising buildings based on location and ventilation type, and applying design standards accordingly.
What are the two overheating risk categories for buildings?
‘Moderate risk’ (England, excluding high-risk areas) and ‘High risk’ (specific urban and suburban areas).
What percentage of glazing is allowed for south-facing façades in high-risk areas with cross-ventilation?
15% of floor area, with 22% in the most glazed room.
What shading solutions are recommended for high-risk areas?
External shutters, glazing with a maximum g-value of 0.4, or overhangs with a 50-degree altitude cut-off.
What is the minimum free area requirement for cross-ventilated buildings in high-risk locations?
The greater of 6% of floor area or 70% of glazing area.
What is dynamic thermal modelling?
It is a method that uses software to predict overheating risk in residential buildings based on weather data and building characteristics.
What standard must be followed for dynamic thermal modelling?
CIBSE’s TM59 methodology for predicting overheating risk.
What are some situations where dynamic thermal modelling might be preferred over the simplified method?
For buildings with high insulation levels, unique site conditions, or significant shading from nearby buildings or landscape.
What must be submitted to the building control body when using dynamic thermal modelling?
A report demonstrating compliance with CIBSE’s TM59, including key details such as occupancy, equipment profiles, and ventilation strategy.