The government recently announced that modern methods of construction (MMC) will be central to its new affordable homes programme to help deliver high quality, more energy efficient homes
at a faster rate. It claims that homes built using these techniques can reduce heating bills by up to 70% and have 80% fewer defects.
The benefits of applying MMC methods to construction include faster build, superior quality, reduced waste and cost savings. CIBSE estimates that on average a 13.4% cost saving can be achieved when prefabricating compared to conventional onsite builds.
So where does heating fit into the programme? Prefabricated and modular heating solutions, which fall under Category 5 under the MMC framework, offer an important opportunity to centralise the heating system and so support our 2050 decarbonisation goals.
The shift towards heat networks as a means of reducing carbon emissions is driving the demand for central energy plant rooms and individual service pods, both of which can be prefabricated offsite. Where a heat network supplies energy to a residential development, installing preassembled utility cupboards within each dwelling can significantly help the overall delivery of the programme.
A utility cupboard is a packaged service pod containing a full suite of HVAC, including a Heat Interface Unit (HIU) and electrical components, that is fabricated offsite and installed as a complete unit.
The pods can be customised to suit the exact layout, service connections and spatial requirements of each building, ensuring best use of available space.
Prefabricating the pods offsite using specialist equipment in a factory environment, as opposed to building them onsite, helps ensure improved quality, accuracy and efficiency.
With improved quality control and pre-testing, designers, specifiers and contractors can be assured that the exact specification will be met, reducing the level of risk and costs during the construction stage.
Once onsite, the pods can be installed more quickly and easily integrated into the volumetric build. Snagging and de-snagging issues are vastly reduced, helping to cut costs and disruption. This method also enables onsite safety to be prioritised and reduces the risk of accidents due to the reduction of hot works. With fewer trades and trade days required onsite, it also successfully overcomes the skills shortage within the heating industry, enabling the challenging demands for new housing to be met.
And crucially, in COVID times, it makes it easier to adhere to social distancing by reducing the number of skills, trades, workers and time spent onsite.
A key benefit of offsite fabrication is that it enables mass customisation across the development.
However, it’s important to note that the process requires better front planning and more detailed design to be used at an earlier stage than with traditional manufacturing methods. For this reason, early integration, engagement and collaboration across the whole project team – including the architect, developer, consultant, contractor and manufacturer – is essential to unlock the full potential of prefabrication. Addressing every detail from the start also gives the customer greater cost certainty and confidence that the project will be delivered on time and to budget.
Battersea Power Station
A case in point is the Battersea Power Station development. The iconic Grade II listed building and surrounding area is undergoing a transformational refurbishment to bring it into modern use. Due to open in 2021, the building will house more than 100 shops, restaurants and cafes, an event venue, office space – including Apple’s new London Campus – and 253 residential apartments.
Packaged Plant Solutions, part of Baxi Heating, supplied offsite fabricated utility cupboards for the residential apartments. The final pods included a HIU/CIU for heating and cooling, mechanical ventilation heat recovery, underfloor heating, electrical distribution, and metering and billing devices.
Due to its heritage status, the building presented significant challenges in terms of design and logistics.
However, early engagement and collaboration from the outset with Battersea Power Station Development Company and Mace, the Principle Contractor, provided the opportunity for all stakeholders to discuss the project and gain a clear understanding of the customer’s requirements. This was critical to avoid any changes to the design once production had begun which would have had an impact on delivery and budget.
Together with Mace’s architects and consultant, the Packaged Plant Solutions team addressed every element – including access to the electrical consumer units for ease of future maintenance and cable trunking, routing and containment. Specifying the right material for the pod was an important consideration as this can have implications on both acoustic performance and safety in high-rise developments.
BIM models were produced for visualisation purposes, showing each element in the pod, its precise location and available space. This removed the risk of potential clashes with other services once the pods were installed.
We also produced a sample of the finished unit before starting mass production to enable all parties to consider every aspect of the unit and how it would function once in position.
The opportunity to work alongside the M&E designers and lend manufacturer expertise meant that a detailed design could be assessed and approved at the early stages. Only once the standardised approach was agreed was the production line set up for the manufacturing process to begin.
By manufacturing the full solution offsite with end of-line-testing, the risk of human error was reducedsignificantly, while the rapid integration of the pods saved huge amounts of time on the overall project. To put it into context, it takes three hours to connect one utility cupboard using MMC techniques, whereas an onsite installation can take up to five days.
The success of the utility cupboard element at the Battersea Power Station development project demonstrates the value-added benefits of using offsite fabricated heating solutions in both refurbishment and new build multi occupancy developments.
Increasing use of modern solutions like these is clearly critical if we are to tackle the heating industry’s skills shortage, meet the huge demand to create new housing stock safely through increased productivity and help the UK achieve its 2050 net zero emissions goal. At the same time, the process supports the ‘golden thread’ of information for buildings, for improved performance and safety.
But early engagement and full commitment are essential to achieve the most efficient and successful design. With our proven experience and expertise in delivering complete turnkey heating solutions – from packaged plant rooms and complete energy centres to pre assembled service pods and skid-mounted boiler rig modules – we at Baxi Heating look forward to continuing to work with developers to address the carbon challenges and support the faster, safer delivery