Radon protection for new domestic extensions and conservatories with solid concrete ground floors (GG 73 revised)
BRE (Building Research Establishment) is an independent, research-based consultancy, testing and training organisation, operating in the built environment and associated industries.
Radon protection for new domestic extensions and conservatories with solid concrete ground floors (GG 73 revised) was written by Chris Scivyer and published by BRE on 13 January 2015.
It replaces guidance published in 2008 and should be read in conjunction with BRE Report BR 211, Radon: guidance on protective measures for new buildings. Two companion Good Building Guides cover radon-protective measures for new dwellings and new large buildings such as workplaces.
Radon is a natural, colourless, odourless, radioactive gas formed by the radioactive decay of small amounts of uranium that occur naturally in all rocks and soils. It can move through cracks and fissures in the subsoil and eventually to the atmosphere. Most of this radon will disperse harmlessly into the outdoor air, but some will collect in spaces under or within buildings.
This 8-page Good Building Guide gives practical advice about the installation of radon-protective measures in new domestic extensions and conservatories with solid concrete ground floors. It will also help house owners and builders in radon-affected areas assess whether protection is needed for a new extension or conservatory and determine the level of protection that is required.
The contents of the guide are:
- What is radon and why consider it for new extensions?
- UK building regulations.
- Determining whether radon protection is needed.
- Protective measures-Basic radon protection.
- Radon barriers.
- High water table.
- Fill and blinding.
- Maintaining ventilation to existing suspended ground floors.
- Subfloor depressurisation and sumps.
- References.
- Further reading.
[edit] Find out more.
[edit] Related articles on Designing Buildings Wiki
- BRE articles on Designing Buildings Wiki.
- BRE Buzz articles on Designing Buildings Wiki.
- BRE Buzz.
- BREEAM.
- Building Research Establishment.
- Contaminated land.
- Cover systems for land regeneration - thickness of cover systems for contaminated land (BR465).
- Ground conditions.
- Methane and other gasses from the ground.
- Radon.
- Radon: Guidance on protective measures for new buildings BR 211.
- Radon protection for new dwellings GG 74.
- Radon protection for new large buildings GG 75.
- Radon solutions in older homes GR 38.
- Site appraisal.
- Site investigation.
- Soil survey.
- Solid and liquid contaminants risk assessments.
Featured articles and news
Homes, landlords. tenants and the new housing standards
What will it all mean?
The Architectural Technology podcast: Where it's AT
Catch-up on the latest episodes.
Edmundson Apprentice of the Year award 2026
Entries now open for this Electrical Contractors' Association award.
Traditional blue-grey slate from one of the oldest and largest UK slate quarries down in Cornwall.
There are plenty of sources with the potential to be redeveloped.
Change of use legislation breaths new life into buildings
A run down on Class MA of the General Permitted Development Order.
Solar generation in the historic environment
Success requires understanding each site in detail.
Level 6 Design, Construction and Management BSc
CIOB launches first-ever degree programme to develop the next generation of construction leaders.
Open for business as of April, with its 2026 prospectus and new pipeline of housing schemes.
The operational value of workforce health
Keeping projects moving. Incorporating unplanned absence and the importance of health, in operations.
A carbon case for indigenous slate
UK slate can offer clear embodied carbon advantages.
Costs and insolvencies mount for SMEs, despite growth
Construction sector under insolvency and wage bill pressure in part linked to National Insurance, says report.
The place for vitrified clay pipes in modern infrastructure
Why vitrified clay pipes are reclaiming their role in built projects.
Research by construction PR consultancy LMC published.
Roles and responsibilities of domestic clients
ACA Safety in Construction guide for domestic clients.
Fire door compliance in UK commercial buildings
Architect and manufacturer gives their low down.






















