External channel drainage systems can often be an overlooked factor in many projects, says William Poynter of ACO Water Management, explaining why architects should consider the aesthetic benefits of different options while addressing practical challenges
The significance of drainage systems for housing projects is not always a key design priority for architects. Despite this, there is an opportunity to harness this unconsidered element, through both a choice of material and the type of drainage system, which can add aesthetic value to a house design. For example, the first thing any developer or builder, and therefore architect, should think about when designing a drainage system for a housing development is where the rainwater will flow. When you’re focusing on driveways and paved areas, for example, you need to be aware of the falls on-site and account for channels accordingly. As for doorways and patio areas, threshold drainage is required. Channel depths are also a factor to consider. Some building sites have restrictions as to the depth of the channel system, which would rule out certain channel sizes. Deeper channels are recommended, especially for driveways, but if that’s not possible systems, can be widened to ensure the necessary volume is provided.
Can drainage systems impact the design of a new build?
One of the first challenges for many architects when working on a domestic project is how a quality finish will be achieved for all aspects of the works, including drainage. Understandably, customers want to create a certain appearance for their homes: one that showcases premium quality. Pushing for a specification of a grating element with the right aesthetic can add a subtle yet important touch to a project. For example, some customers want drainage systems to be subtle and barely noticeable. These systems are inserted seamlessly between brickwork to provide a clean and contemporary finish. If a bold finish is desired, architects could use grated channels to make a feature of the drainage through mosaic, slotted or lightening gratings. Drainage made from stainless steel, cast iron, aluminium or composite, can also enhance a bold finish. It is important to consider maintenance and placing access units in a channel run. Most drainage systems are designed for easy jet-wash maintenance but the more discreet drainage options require thought about the placement of access units.
Complete the look
When planning and drawing the design of a new housing project, there are a number of drainage channels which help complete the look, from contemporary stainless steel to antique cast iron, meaning the finish can replicate the initial designs. There may be some reservations about utilising aesthetically pleasing systems, in case they do not provide the appropriate functionality of what is expected. To caveat this, architects should ensure that any drainage channels that are recommended to fit with the design have the appropriate load class requirements. There are load classes that architects should look out for in a new housing project (namely B 125 and A 15). B 125 rated systems should be installed for private car parks or areas where domestic vehicles will be present. For other areas of the house, such as patios and garage thresholds, A 15 rated drainage is sufficient.
As well as playing an integral role of the surrounding infrastructure of a building, drainage can also play its part in the design and should therefore be carefully considered by architects. As a final note, grating visualiser tools are available from some water management specialists on the many different options available.
For more information on ACO Water Management’s extensive portfolio of aesthetic drainage solutions for housebuilders, please visit: www.aco.co.uk/housing
William Poynter is design service advisor at ACO Water Management