The meaning of bay in the construction industry
The term ‘bay’ has numerous applications in the construction industry.
- When used in relation to a window, (as in ‘bay window’), it describes a part of the construction (in plan and elevation) that protrudes outwards from the main building line and is partly or wholly glazed. Bay windows take various shapes such as curved, rectilinear, polygonal etc.
- An elevation can also be divided into bays, whether these are subtle, eg delineated by rainwater pipes or movement joints, or created by more three-dimensional features such as a crenulated configuration of the walls.
- A bay in a building can also describe an internal area that is demarcated by structural elements. For example, in a building that comprises a grid with columns spaced at 6m-centres in both x- and y-directions, the result on-plan will be the creation of bays measuring 6m x 6m – assuming measurements are taken to the grid centre-lines.
- Bay can also refer to an area that is connected to and forms a small annexe to a larger area, such as a subsidiary area used for some function connected to the activity of the main area, e.g a loading bay.
- Bay (or bays) can also refer to single parking spaces that are created by painted lines on the ground.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Call for greater recognition of professional standards
Chartered bodies representing more than 1.5 million individuals have written to the UK Government.
Cutting carbon, cost and risk in estate management
Lessons from Cardiff Met’s “Halve the Half” initiative.
Inspiring the next generation to fulfil an electrified future
Technical Manager at ECA on the importance of engagement between industry and education.
Repairing historic stone and slate roofs
The need for a code of practice and technical advice note.
Environmental compliance; a checklist for 2026
Legislative changes, policy shifts, phased rollouts, and compliance updates to be aware of.
UKCW London to tackle sector’s most pressing issues
AI and skills development, ecology and the environment, policy and planning and more.
Managing building safety risks
Across an existing residential portfolio; a client's perspective.
ECA support for Gate Safe’s Safe School Gates Campaign.
Core construction skills explained
Preparing for a career in construction.
Retrofitting for resilience with the Leicester Resilience Hub
Community-serving facilities, enhanced as support and essential services for climate-related disruptions.
Some of the articles relating to water, here to browse. Any missing?
Recognisable Gothic characters, designed to dramatically spout water away from buildings.
A case study and a warning to would-be developers
Creating four dwellings... after half a century of doing this job, why, oh why, is it so difficult?
Reform of the fire engineering profession
Fire Engineers Advisory Panel: Authoritative Statement, reactions and next steps.
Restoration and renewal of the Palace of Westminster
A complex project of cultural significance from full decant to EMI, opportunities and a potential a way forward.
Apprenticeships and the responsibility we share
Perspectives from the CIOB President as National Apprentice Week comes to a close.





















