Dubai Municipality has released the first edition of its unified building code, the Dubai Building Code (DBC).
The code was announced in Autumn 2020 with the aim of setting standards for construction that promote sustainable development and innovation in building design. It is also hoped that the DBC will both reduce the costs of construction projects and speed up the completion of the design phase. This article reviews sections of the code relevant to architecture and the impact it may have on the design of projects
Prior to the DBC being issued, design teams and contractors relied on various different documents to ensure their building projects meet the required standards. Ensuring that the project was designed and constructed in accordance with the requirements of both the UAE Fire and Life Safety Code as well British Standards (BS) and American Standards (ASTM) would generally result in a compliant building.
As such, there was no single source that could be relied upon, and designers were required to stay up to date with any changes in British or American Standards.
A REVIEW OF THE DBC
The new code consists of ten parts:
D. Vertical Transportation
E. Building Envelope
G. Incoming Utilities
H. Indoor Environment Security
The following four parts are relevant to architecture and architects.
Part A: General
The DBC introduces its own requirements whilst still relying upon existing codes and international standards. International codes are to be used in their latest edition except where the DBC lists an edition.
The DBC stipulates that where a conflict exist between the DBC and referenced codes or standards then the most restrictive or highest performance requirement prevails.
The DBC also introduces the principle of “safe by design”. In doing so the DBC refers readers to the UK ‘Construction (Design and Management) Regulations.’ Although the first edition does not mandate compliance, it is a step in the right direction.
The DBC excludes certain structures from its scope including: metro stations, hydraulic structures, buried and overhead utilities, power stations, antennas and masts, wind turbines and nuclear facilities, although metro stations are specially mentioned in some sections of the DBC.
However, the DBC has included some odd requirements which seem to go against sustainable development and a reduction in construction costs such as minimum ceiling heights, discussed below.
Part B: Architecture
This section stipulates certain minimum space standards. It includes minimum clear heights, with a clear height of 2.7m being required in living and bedroom spaces. As a comparison, the International Residential Code requires a minimum ceiling height of 2.134m (seven foot)
Although on a par with ceiling heights for hotels, this minimum requirement will mean taller buildings requiring more construction materials. Given Dubai’s fondness for glazed façades, this will also add to the heat load applied to buildings.
In contrast, Part B also stipulates a minimum requirement of at least 10% (of cost) for the use of recycled content, and also requires that at least 25% of timber and timber-based products be from certified or accredited sources.
Missing from Part B is the requirement for stair risers (R) and treads (T) to comply with the equation:
650 mm < 2R + T < 700mm
While this is stipulated in the Dubai Universal Design Code, there have been instances where designers have failed to design staircases to meet this requirement, and so its repetition in the DBC would have been useful.
Part C: Accessibility
Part C references BS 8300 ‘Design of buildings and their approaches to meet the needs of disabled people – Code of practice’, ‘Approved Document M – Volume one’, and the United States ‘Americans with Disability Act – Standards for accessible design.’
This section then replicates requirements from these standards, as well as the Dubai Universal Design Code, taking the most stringent versions as DBC’s minimum requirement.
However some confusion may arise wth regard to wheelchair ramps, where the DBC gives a dimension of 1000mm or greater for the distance between handrails, whereas the DUDC gives a strict dimension of 1000mm.
Part E: Building Envelope
This section attempts to deal with what we see as one of the biggest issues with construction in the region: thermal bridges and interstitial (or surface) condensation. Whilst designers and contractors should be well aware of the impact the local climate has on construction, the introduction of the DBC now provides no excuse for poor detailing or workmanship.
The DBC states that for all new air-conditioned buildings, thermal bridges are to be eliminated or insulated to reduce the amount of heat transfer. It also states that the building envelope shall be designed and constructed such that it is not adversely affected by interstitial condensation, nor does it promote surface condensation.
The DBC refers to BS5250 for further guidance on the control on condensation, although it may have been best placed to refer to the US Environmental Protection Agency document ‘Moisture Control Guidance for Building Design, Construction and Maintenance’, given the climatic similarities with some areas of the US.
The DBC is a welcome one stop shop for design teams and contractors as a reference to the codes and standards they to which they need to adhere. However, as most of the document refers to other standards, it does not relieve them of keeping up to date with the latest updates in either British or American Standards. It is this responsibility to keep up to date with the latest requirements, and the copy and paste nature of common details, that could leave design teams open to noncompliance.
For the insurance market, the need to comply with the DBC could act as a catchall for policies, i.e. where policies are silent on matters covered by the DBC they could be deemed included.