Principal storey
The building regulations set out legal requirements for specific aspects of building design and construction. A series of approved documents provide general guidance about how different aspects of building design and construction can comply with the building regulations.
Approved document M provides guidance for satisfying Part M of the building regulations: Access to and use of buildings, which requires the inclusive provision of ease of access to, and circulation within, buildings, together with requirements for facilities for people with disabilities.
Approved document M, Volume 1: Dwellings (2015 edition incorporating 2016 amendments), defines the ‘principal storey’ as:
‘The floor level (of the dwelling) on which the main living space is located, where this is not the entrance storey.’
Where the ‘entrance storey’ is; '...the floor level (of the dwelling) on which the principal private entrance is located’, that is, '...the entrance to the individual dwelling that a visitor not familiar with the dwelling would normally approach (usually the ‘front door’ to a house or ground floor flat.’
[edit] Related articles on Designing Buildings Wiki
- Access and inclusion in the built environment: policy and guidance.
- Access consultant.
- Accessibility in the built environment.
- Accessible threshold.
- Approach route.
- Approved document M.
- Changing lifestyles.
- Equality Act.
- Inclusive design.
- Localised obstruction.
- Lifetime homes.
- People with disabilities.
- Point of access.
- Principal communal entrance.
Featured articles and news
Do you take the lead in a circular construction economy?
Help us develop and expand this wiki as a resource for academia and industry alike.
Warm Homes Plan Workforce Taskforce
Risks of undermining UK’s energy transition due to lack of electrotechnical industry representation, says ECA.
Cost Optimal Domestic Electrification CODE
Modelling retrofits only on costs that directly impact the consumer: upfront cost of equipment, energy costs and maintenance costs.
The Warm Homes Plan details released
What's new and what is not, with industry reactions.
Could AI and VR cause an increase the value of heritage?
The Orange book: 2026 Amendment 4 to BS 7671:2018
ECA welcomes IET and BSI content sign off.
How neural technologies could transform the design future
Enhancing legacy parametric engines, offering novel ways to explore solutions and generate geometry.
Key AI related terms to be aware of
With explanations from the UK government and other bodies.
From QS to further education teacher
Applying real world skills with the next generation.
A guide on how children can use LEGO to mirror real engineering processes.
Data infrastructure for next-generation materials science
Research Data Express to automate data processing and create AI-ready datasets for materials research.
Wired for the Future with ECA; powering skills and progress
ECA South Wales Business Day 2025, a day to remember.
AI for the conservation professional
A level of sophistication previously reserved for science fiction.
Biomass harvested in cycles of less than ten years.
An interview with the new CIAT President
Usman Yaqub BSc (Hons) PCIAT MFPWS.
Cost benefit model report of building safety regime in Wales
Proposed policy option costs for design and construction stage of the new building safety regime in Wales.
Do you receive our free biweekly newsletter?
If not you can sign up to receive it in your mailbox here.






















