The Value of 3D Noise Modelling
As the old saying goes, “a stitch in time, saves nine”. The meaning being that it is always more efficient to solve a minor problem before it becomes a major one.
Good acoustic advice is a bit like that. It is much more efficient to design a development with acoustics in mind from the start rather than having a development assessed at the last minute, or worst still, not having it assessed at all.
3D noise modelling is a cost-effective tool for assessing the acoustic design of a development at an early stage. The models are used to predict environmental noise propagation, often over large areas or in urban environments, and allow very complex calculations to be carried out quickly and efficiently. The results, which are often displayed as colour noise contours, are also a simple way of illustrating the noise environment to non-acoustic specialists, which can be important when communicating with local planning authorities or other stakeholders.
Different noise control measures and layout options can be tested in the model to optimise the design whilst ensuring that an acceptable impact is achieved. As well as helping support planning applications, a good design will also maximise land use and minimise the risk of future complaints and noise issues. This can represent significant cost savings as retrospective noise control is normally significantly more expensive than incorporating noise control at the design stage. Importantly, any noise control costs can also be allowed for if they are known about at the outset of a project, rather than at the end of a project when budgets are depleted.
Model of a new industrial facility including a number of biodiesel generators (shown bottom left). A noise barrier was designed within the model to ensure the facility would not disturb the residences (shown top right).
Modelling can also be very useful for informing the detailed design of developments. Shown below is the printout from a noise model that was used to predict noise from existing roads affecting a new residential development.
Model of new mixed-use scheme adjacent to a busy main road.
The dots on the facades of the development show the predicted noise levels. The red dots show the highest noise levels, which are due to the proximity to the road. The grey and green dots represent the lower noise levels towards the rear of the development.
In this case, by predicting the external noise levels incident on every façade, it was possible to ensure that the sound insulation of the glazing and ventilation was accurately specified for all facades. This meant that the glazing and ventilation was only enhanced where strictly necessary, thus minimising glazing and ventilation costs. Over large developments, these cost savings can be significant.
Below is another example where a model was used to inform the design of mechanical plant associated with a new five-star hotel and residential development. The plant was mostly located on the roof of the building and the model was use to specify appropriate noise control to ensure that guests and residents in the development would not be disturbed.
Model of mechanical plant noise emissions associated with new hotel and residential development. The vertical coloured area shows the spread of noise from the rooftop plant. The noise is directed upwards to minimise emissions affecting sensitive areas.
By modelling the plant noise emissions early in the design process, it was possible to make allowances for the required noise control measures (attenuators, enclosures, acoustic lagging, acoustic screens, inherently quiet plant items etc) both in terms of cost and also design and space planning.
In summary, 3D noise modelling can be a useful tool to optimise the design of new developments and reduce project costs and risks. If you would like any further information on 3D noise modelling or are interested in whether it will benefit one of your projects, please contact Chris McNeillie or Patrick Allen on 01234 834 862.