Building Regulations 2022: Shading Solutions for Overheating

If you work in construction, you’ve probably heard of the new building regulations that came into force in June 2022. Covering energy efficiency, ventilation, and overheating, these changes are designed to protect the health of occupants and help the UK meet its net zero target.

Part O of the new regulations concerns combating the potential risk of overheating. New buildings must be designed and constructed to:

1. Limit unwanted solar gains in summer.
2. Provide an adequate means of removing excess heat from the indoor environment.

To meet this requirement, one of two methods can be used: the simplified method or the dynamic thermal modelling method. Both methods involve the use of external shades like awnings and roller screens.

At Broadview, we work with builders to design shading solutions for all property types. Read on to find out the difference between the two methods for preventing overheating, and how effective shading can help you fulfil their requirements.

The Simplified Method

For the simplified method, the strategy for reducing overheating depends on the location of the new residential building. The building’s overheating risk category is determined by its location in one of the following areas:

1. ‘Moderate risk’ location - England, excluding high risk parts of London.
2. ‘High risk’ location - urban and some suburban parts of London.

To limit solar gains, all of the following standards should be followed:

1. Provide effective shading for buildings in the high risk location.
2. Do not exceed the maximum glazing area percentages.
3. Do not exceed the maximum glazing area percentages of the most glazed room.

Whether the building has cross-ventilation or not also has an impact.

For a more detailed explanation, view Table 1.1 and Table 1.2 in the full Part O document.

Residential buildings in high risk locations must provide shading for glazed areas between compass points north-east and north-west via the south. Shading should be provided by one of the following means:

1. External shutters with means of ventilation.
2. Glazing with a maximum g-value of 0.4 and a minimum light transmittance of 0.7.
3. Overhangs with 50 degrees altitude cut-off on due south-facing façades only.

The Dynamic Thermal Modelling Method

This method uses dynamic thermal modelling to predict the overheating risk for residential homes.

Using weather data and building characteristics, dynamic thermal modelling predicts the internal conditions and energy demands of a building at short time intervals. It may offer more design flexibility than the simplified method in the following situations:

1. Residential buildings with very high levels of insulation and airtightness.
2. Residential buildings with specific site conditions that mean the building is not well represented by the two risk categories mentioned above.
3. Residential buildings that are highly shaded by neighbouring properties, structures or landscape.

Using this method, solar gains in summer should be limited by any of these means:

• Fixed shading devices, comprising any of the following.
  • Shutters
  • External blinds
  • Overhangs
  • Awnings
     
• Glazing design, involving any of the following solutions.
  • Size
  • Orientation
  • G-value
     
• Depth of the window reveal.
• Building design – for example, the placement of balconies.
• Shading provided by adjacent permanent buildings, structures or landscaping.

Excess heat should be removed from the residential building by any of the following means:

• Opening windows (the effectiveness of this method is improved by cross-ventilation).
• Ventilation louvres in external walls.
• A mechanical ventilation system.
• A mechanical cooling system

For a more detailed look at the new regulations, read through the Approved Documents on the UK government’s website.

Get a Quote on Trade Shading Solutions

It’s important you take these changes into account when designing a new residential building. Not only does this ensure your build is legal, but it prevents excessively high indoor temperatures from affecting the health and welfare of any occupants.

At Broadview, we’ll work with you to design and install a high-coverage shading system that will help your building stay in line with the new regulations. You can trust us to install your new system to a high standard of quality, following all Health and Safety guidelines and carrying out our work carefully, considerately, and precisely.

Get a quote on our shading solutions online or by calling us on 01202 679 012!