Internal space
Internal space is a generic phrase to describe the space within an enclosed boundary (as opposed to a space outside of that boundary).
It might be used in association with any kind of contained space - or a container, where in might be more specifically referred to as internal volume. Effectively the height, by the width by the depth.
In terms of buildings internal space may be more likely referred to as interior space (as opposed to exterior space) with the boundary being the building envelope.
The measures associated with internal space might be floor space, useful or total useful floor area (UFA/ TUFA), Total rentable area, treated floor area (TFA) etc - for more information see Floor area. The space would then be that area multiplied by the internal height but it may be used as quite a generic term and the specifics of what is included in different contexts should be defined. For example an unheated garage or cellar in a house might be considered an internal space but is not part of the treated floor area, because these spaces are usually uninsulated, unheated or untreated.
[edit] Related articles on Designing Buildings
Featured articles and news
Preparing safety case reports for HRBs under the BSA
A new practical guide to preparing structural inputs for safety cases and safety case reports published by IStructE.
Male construction workers and prostate cancer
CIOB and Prostate Cancer UK encourage awareness of prostate cancer risks, and what to do about it.
The changed R&D tax landscape for Architects
Specialist gives a recap on tax changes for Research and Development, via the ACA newsletter.
Structured product data as a competitive advantage
NBS explain why accessible product data that works across digital systems is key.
Welsh retrofit workforce assessment
Welsh Government report confirms Wales faces major electrical skills shortage, warns ECA.
A now architectural practice looks back at its concept project for a sustainable oceanic settlement 25 years on.
Copyright and Artificial Intelligence
Government report and back track on copyright opt out for AI training but no clear preferred alternative as yet.
Embedding AI tools into architectural education
Beyond the render: LMU share how student led research is shaping the future of visualisation workflows.
Why document control still fails UK construction projects
A Chartered Quantity Surveyor explains what needs to change and how.
Inspiration for a new 2026 wave of Irish construction professionals.
New planning reforms and Warm Homes Bill
Take centre stage at UK Construction Week London.
A brief run down of changes intentions from April in an onwards.
Reslating an ancient water mill
A rare opportunity to record, study and repair early vernacular roofs.
CIOB Apprentice of the Year 2025/26
Construction apprentice from Lincoln Mia Owen wins this years title.
Insulation solutions with less waste for a circular economy
Rob Firman, Technical and Specification Manager, Polyfoam XPS explains.
Recycled waste plastic in construction
Hierarchy, prevention to disposal, plastic types and approaches.
UK Net Zero Carbon Buildings Standard V1 published
Free-to-access technical standard to enable robust proof of a decarbonising built environment.






















