Conservatories have historically benefited from a broad exemption from Building Regulations in England, but the position has become more complex following changes introduced in 2023. Understanding the current rules is important before starting any conservatory project.

The Historic Exemption

Before January 2023, a conservatory was exempt from Building Regulations if it met certain conditions: it was built at ground level, was separated from the house by external-quality walls, doors, or windows, had a translucent or transparent roof covering at least 75 percent of its area, had an independent heating system with its own controls, and was under thirty square metres in floor area. Under these conditions, the conservatory was treated as an unheated buffer space rather than a habitable room and was exempt from the thermal performance and structural requirements of the main Regulations.

What Changed in 2023

From 15 June 2023, new Building Regulations introduced requirements for conservatories and similar glazed extensions. The key change is that conservatories above a certain size threshold must now meet minimum energy efficiency standards, specifically U-value requirements for the glazing, roof, and walls. The threshold for these new requirements applies to conservatories with a floor area over thirty square metres, which are now subject to the same energy efficiency requirements as extensions.

For conservatories under thirty square metres, the pre-2023 exemption conditions broadly continue to apply, subject to meeting the current glazing standards. However, the separation requirement, that the conservatory be separated from the main house by walls, doors, or windows of external quality, remains important. If the conservatory is fully open to the main house without a separating element, it is treated as an extension and subject to full Building Regulations regardless of size.

The Separation Requirement in Practice

Many homeowners remove the original separating doors or windows between the conservatory and the main house to create a more integrated space. Doing so removes the basis for the conservatory exemption and means the structure must comply with Building Regulations as a full extension. If you are planning to remove or not install the separating elements, seek Building Control advice before proceeding.

Electrical Work in a Conservatory

Regardless of whether the conservatory itself requires Building Regulations approval, any electrical work carried out within it, including sockets, lighting circuits, and heating installations, must comply with Part P of the Building Regulations. This means either being carried out by a registered electrician under a competent person scheme who can self-certify the work, or being inspected and certified by Building Control.

Summary

Conservatories under thirty square metres that are separated from the main house by external-quality walls, doors, or windows, have a substantially translucent roof, and meet current glazing standards generally remain exempt from Building Regulations in England. Conservatories over thirty square metres, those without proper separation from the main house, and those that are fully heated and integrated as living space may require Building Regulations approval under the updated 2023 rules. Electrical installations in conservatories always require compliance with Part P regardless of the conservatory's overall exempt status. When in doubt, consult Building Control.