Aurecon’s Building Services Professional, Ashley Underwood, explains what value engineering is and why having expertise in it should be a prerequisite when sourcing engineering consultants for projects.
“Value engineering looks at the capital cost of a project and determines whether the function and quality of the results is equal to the perceived value. It’s a management approach that focuses on the benefits, payback and overall return on investment that a client will achieve instead of looking at different parts of a project in silos,” says Underwood.
While it’s easy to see the benefit of value engineering, problems arise because it is often applied late in a project. When value engineering is incorporated during the design and concept phase, consultants are able to thoroughly look at the life cycle cost of each decision, and this type of analysis includes financial payback, as well as environmental impacts such as carbon emissions and material selections.
“The rising cost of energy has essentially aligned the financial and environmental benefits for many energy-saving initiatives. With value engineering of energy-savings, you are now able to create a building that will result in a true payback for the client, but this approach needs to be implemented in the concept and design stages. The number of Green Star rated projects that Aurecon has worked on is a testament to what is achievable when combining the efforts of environmental modelling software programs, mechanical engineering expertise and buildings sciences consultants early on in a project,” he says.
Aurecon is a recognised leader in the use of a range of powerful environmental modelling software programs to optimise the performance of buildings. The 3D modelling software takes every aspect of a building into consideration.
“Engineers and designers can improve the occupants’ comfort using 3D modelling of a building’s orientation and form, external shading and fabric performance. We can make real changes to the energy consumption of the building by looking at the building services as a whole, which includes aspects such as mechanical systems, hot water generation, escalators, lighting systems and any miscellaneous services such as irrigation,” comments Underwood.
It is important to get the right mix. Normally, the building shell, including insulation and glazing spec, is optimised to ensure high thermal comfort for the people occupying the perimeter zones of the building, while increasing insulation beyond this has only a small effect on the building’s energy use.
“To achieve additional significant energy-savings, we look carefully at the mechanical and electrical systems,” says Underwood. “For the electrical systems, we strive to only use energy-efficient lighting, while for the mechanical systems, we generally recommend a high efficiency plant with a range of energy-saving features such as, economy cycles, CO2 based demand control of fresh air, CO2 based demand control of car park ventilation, etc.
“Aurecon has developed a number of calculation procedures that helps us to ensure 3D modelling is relevant in a South African context, which is a unique value-adding benefit to our clients.”
Aurecon’s use of 3D modelling software, coupled with the in-house calculation methodologies that the company has developed for local buildings, is only a part of the value engineering services that we offer. The fact that the mechanical engineers and building sciences professionals are able to work together to find sustainable, energy-saving solutions is the thread that ties everything together in order to provide real value for clients.
“The digital recreation of a proposed building isn’t merely a placeholder or an estimate of what could potentially be achieved, it’s a very accurate replica of how the building will operate and function once constructed,” asserts Underwood. “We use the energy simulation results to guide the implementation of energy sub-metering strategies and then to track and manage energy use within the operational buildings.”
Aurecon achieved a first in Tshwane in 2011 when its Lynnwood Bridge Office Park building, situated alongside the N1 highway, achieved a 4 Star GreenStar SA – [Office Design v1] rating from the Green Building Council of Southern Africa. The company has recently completed another ‘green’ office building in the same precinct achieving a 5-Star rating, which will comprise five basement levels, as well as ground plus five floors.
The project team took a value engineering approach during the design and construction phase of the new building. Unlike the traditional model of three overlapping financial, social and environmental circles where the only commonality (or triple bottom line) is the small area in the middle, a value engineering model is a strong sustainability model. The environmental and economic benefits are a subset of the sustainability aspirations, and are the core values underpinning every aspect of the design solution.
“During the design phase of the new Lynnwood Bridge building, each energy-saving feature was modelled and calculated in order to predict how each aspect would impact the electricity consumption of the actual building. The state-of-the-art 3D modelling software, coupled with the expertise drawn from the company’s global team, allowed us to create data that accurately showed the future building’s performance, predict utility bills, and create energy targets to track building performance,” says Underwood.
One of the biggest challenges of current energy-saving initiatives in buildings is when a supplier offers a solution that won’t necessarily lead to a payback for the client. Underwood stresses that the effect of any energy-saving component needs to be analysed before being adopted.
“Supplier data needs to be put into a South African context. The supplier could be providing data that is relevant for countries in Europe where there is a cooler climate, or the supplier could take a single operating point and extrapolate the data over the course of an entire year, which could lead to misleading results. In order to know for sure what your building’s payback will be, clients need to take a value engineering approach and make sure they know how the building will perform once the energy-saving initiatives have been implemented,” he says.
“Trying to predict the impact of a chilled beam system or an energy-efficient heating, ventilation and air conditioning (HVAC) system, for example, is impossible without looking at the entire system design holistically, doing the calculations and analysing the results. Advanced 3D modelling software gives engineers the tools they need to predict whether an energy-saving initiative is going to have a marginal or worthwhile return on investment. Clients need to partner with engineering consultancies that have the capability to analyse the effects of different initiatives if they want real value,” emphasises Underwood.