Principal works in the construction industry
According to approved document L of the building regulations, the term 'principal works' means:
| ...the work necessary to achieve the client's purposes in extending the building and/or increasing the installed capacity of any fixed building services. The value of the principal works is the basis for determining a reasonable provision of consequential improvements. |
Where, fixed building services are internal or external lighting systems (not emergency escape lighting or specialist process lighting), fixed systems for heating, domestic hot water, air conditioning or mechanical ventilation, or any combination of those systems.
And, consequential improvements are efficiency improvements consequential to changes to a building, required by regulation 28 of the Building Regulations to make the whole building comply with Part L of the Building Regulations.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Many resources for visitors aswell as new features for members.
Using technology to empower communities
The Community data platform; capturing the DNA of a place and fostering participation, for better design.
Heat pump and wind turbine sound calculations for PDRs
MCS publish updated sound calculation standards for permitted development installations.
Homes England creates largest housing-led site in the North
Successful, 34 hectare land acquisition with the residential allocation now completed.
Scottish apprenticeship training proposals
General support although better accountability and transparency is sought.
The history of building regulations
A story of belated action in response to crisis.
Moisture, fire safety and emerging trends in living walls
How wet is your wall?
Current policy explained and newly published consultation by the UK and Welsh Governments.
British architecture 1919–39. Book review.
Conservation of listed prefabs in Moseley.
Energy industry calls for urgent reform.
Heritage staff wellbeing at work survey.
A five minute introduction.
50th Golden anniversary ECA Edmundson apprentice award
Showcasing the very best electrotechnical and engineering services for half a century.
Welsh government consults on HRBs and reg changes
Seeking feedback on a new regulatory regime and a broad range of issues.
CIOB Client Guide (2nd edition) March 2025
Free download covering statutory dutyholder roles under the Building Safety Act and much more.