Substructure
The Building Cost Information Service (BCIS), Elemental Standard Form of Cost Analysis Principles, Instructions, Elements and Definitions 4th (NRM) Edition published by the Royal Institution of Chartered Surveyors (RICS) in 2012, describes the rules for preparing an elemental cost analysis in standard BCIS format.
It defines the term substructure as:
‘All work below underside of screed or, where no screed exists, to underside of lowest floor finishes including damp-proof membrane, together with relevant excavations and foundations (includes walls to basements designed as retaining walls).’
It suggests that the function of the substructure is to, ‘… transfer the load of the building to the ground and to isolate it horizontally from the ground.’
According to BCIS, the substructure includes:
- Foundations up to and including the damp proof course.
- Lowest floor assembly below the underside of the screed or the lowest floor finish.
- Basement excavation.
- Basement retaining walls up to and including the damp proof course.
This a fairly narrower definition which excludes items such as; finishes, basement walls not in contact with earthwork, retaining walls not providing external walls, and so on.
Some much broader definitions consider the substructure to include all works below ground level, although clearly, this is a fairly ambiguous description.
[edit] Related articles on Designing Buildings Wiki
- Basement.
- Basement excavation.
- Basement v cellar.
- Building Cost Information Service.
- BCIS elements.
- Concept structural design.
- Cost planning.
- Deflection.
- Diaphragm wall.
- Elemental cost plan.
- Excavation.
- Footings.
- Groundworks.
- Planning (Subterranean Development) Bill.
- Structure definition.
- Structural engineer.
- Structural principles.
- Substrate.
- Superstructure.
- Types of structure.
Featured articles and news
Retrofit 25 – What's Stopping Us?
Exhibition Opens at The Building Centre.
Types of work to existing buildings
A simple circular economy wiki breakdown with further links.
A threat to the creativity that makes London special.
How can digital twins boost profitability within construction?
The smart construction dashboard, as-built data and site changes forming an accurate digital twin.
Unlocking surplus public defence land and more to speed up the delivery of housing.
The Planning and Infrastructure Bill
An outline of the bill with a mix of reactions on potential impacts from IHBC, CIEEM, CIC, ACE and EIC.
Farnborough College Unveils its Half-house for Sustainable Construction Training.
Spring Statement 2025 with reactions from industry
Confirming previously announced funding, and welfare changes amid adjusted growth forecast.
Scottish Government responds to Grenfell report
As fund for unsafe cladding assessments is launched.
CLC and BSR process map for HRB approvals
One of the initial outputs of their weekly BSR meetings.
Architects Academy at an insulation manufacturing facility
Programme of technical engagement for aspiring designers.
Building Safety Levy technical consultation response
Details of the planned levy now due in 2026.
Great British Energy install solar on school and NHS sites
200 schools and 200 NHS sites to get solar systems, as first project of the newly formed government initiative.
600 million for 60,000 more skilled construction workers
Announced by Treasury ahead of the Spring Statement.
The restoration of the novelist’s birthplace in Eastwood.
Life Critical Fire Safety External Wall System LCFS EWS
Breaking down what is meant by this now often used term.
PAC report on the Remediation of Dangerous Cladding
Recommendations on workforce, transparency, support, insurance, funding, fraud and mismanagement.
New towns, expanded settlements and housing delivery
Modular inquiry asks if new towns and expanded settlements are an effective means of delivering housing.