Dr Anthony Greer, corporate strategy director of TALO, looks at the drivers for bringing offsite housebuilding technology from Finland to the UK. He shares his insight, experience and international perspective on the offsite housing sector and the wider vision for eradicating fuel poverty and addressing the housing crisis
The UK housing sector now feels very different to a year ago and is much more receptive to MMC. Volumetric has its place, particularly for high rise and multi-occupancy schemes, but there is a renewed energy and interest in advanced panelised and Cat 2 offsite solutions for low rising housing.
Post-election, there are still clear economic challenges, but the macro drivers are better and stronger. The government is pushing hard for new housing – 1.5m new homes by 2029 – and new initiatives to support MMC are coming through that will benefit housebuilders, housing providers and property developers.
Why we need to focus on outcomes
We believe the focus of any business should be on outcomes. Perhaps it is our approach coming from scientific/analytical backgrounds and other sectors such as oil and gas but the commitment to deliver on outcomes – such as significantly reducing energy bills and creating a zero-snag culture – is vital.
Collaboration with others who have that shared vision will help to achieve positive and meaningful outcomes and in the housing sector, this is better quality, energy-efficient homes.
Some lessons from Finland
In Finland, around 70% of all new homes are manufactured offsite and the main driver is the extreme climate. With temperatures as low as -50C and as high as 30C, there is a clear need for exceptional thermal efficiency and to reduce work on site in such temperature extremes.
Drivers for MMC in the UK are the challenges facing the wider construction industry:
- Skills shortages.
- Lack of productivity.
- Substandard quality.
- Rising demand for new housing.
- Reducing environmental impact.
- Improving energy efficiency.
These drivers for offsite are different to those in Finland, but the desired outcome of exceptional quality homes with no or ultra-low energy bills, delivered cost effectively, is equally applicable in both countries.
Unlike in the UK, there is limited mass housebuilding in Finland. The majority of new homes are developed privately. This means offsite housing has to deliver customers’ expectations for quality, design flexibility, high energy and thermal performance to address the climate
extremes, and cost efficiency. These are not constraints for offsite in Finland – and these system capabilities are highly valuable for the UK market.
How to achieve zero snagging in offsite housebuilding
One of the reasons advanced timber superstructures from Finland can deliver such high-quality housing is that there is complete control of the timber – from forest to sawmill, offsite manufacturing to site. This is an entirely DRY process, which we believe is absolutely fundamental to delivering low or zero energy housing.
If high quality, slow grown Nordic timber is protected from the weather at every stage, it never gets wet and therefore never has to dry out over time.
Wet timber means movement – twisting and cracking – which then leads to snagging and heat loss once a house has been built.
When you have dry timber combined with robust offsite manufacturing processes and intelligent design, you can radically reduce air permeability for a higher degree of thermal efficiency – and at no cost premium.
This fabric first approach reduces heat loss and snagging cost efficiently – but that process has to start in the forest and follow through the product lifecycle and including how the structure is installed on site.
The impact of this approach on the quality of new low-rise housing cannot be underestimated.
Why do we need an integrated energy structure?
To build genuinely zero energy homes cost effectively, there are a number of other factors that have to be taken into consideration and designed into every project.
Thermal efficiency of the timber superstructure should not be considered in isolation. A more holistic approach is needed and for that we have to influence the energy strategy.
With this approach, you can remove the need for costly ground or air source heat pumps and energy-intensive gas boilers.
Instead, electricity, hot water and electric underfloor heating are powered by battery storage from solar panels and combined with MVHR (mechanical ventilation and heat recovery).
This integrated strategy – together with the exceptional thermal performance of the timber panelised superstructure manufactured offsite, low energy doors and triple glazed windows – exceeds Passivhaus energy standards as standard and at no cost impediment.
MVHR: A key part of the solution for zero energy homes
We would not deliver a project without MVHR. MVHR systems provide a controlled supply of fresh air throughout the house and use the heat of the exiting air from the inside to warm it up. Moisture levels and air exchanges are then carefully managed.
However, new homes in the UK typically rely on trickle ventilation, allowing an uncontrolled amount of air to exit the house, taking heat with it. The cold air entering the house then needs heating up, which consumes additional energy and increases heating costs, regardless of the U-value of the walls.
We believe this approach is simply not sustainable or effective when there is an urgent need to drive down energy costs and carbon emissions in a climate and cost of living crisis.
Another key benefit of MVHR is that these systems filter all of the air coming into a house, reducing pollutants and particulates. This creates a much healthier internal living environment, particularly for children, the elderly and those with health conditions such as asthma.
This is why MVHR is a key part of the solution to delivering zero energy housing with the wider aim of eradicating fuel poverty.
Case study: The Green Quarter, Bromley
In just eight days, the TALO team built the structures for two four-bed detached family homes in Bromley, Kent.
As the team of just two installers and one crane operative were installing the second home, the first fix M&E was being completed by the client in the first unit. This is the speed of Cat 2 panelised offsite construction. Designed by KHD Architecture, the homes at the Green Quarter for developer Pack Developments will exceed Passivhaus energy standards to reduce or eliminate the need for energy bills, cost efficiently.
The scheme is using TALO’s advanced timber offsite superstructure system, manufactured in Finland from high quality dry Nordic timber, to deliver homes to higher quality standards.
The highly insulated structure with pre-installed triple glazed windows and low energy doors were craned into position as a series of panels ready for external finishing and internal fitout.
David Watkins, director of Pack Developments, said: “The main drivers for using this offsite superstructure system for this project are lower energy bills and improved quality for homebuyers.
“We are delivering new family homes to an exceptional standard with low or zero running costs that are unparalleled in the area. TALO will also help us to achieve a significant reduction on the overall construction programme to allow earlier occupation. We have been
delighted with the progress so far and are now looking at our next scheme using the same system and approach.”
Exceeding Passivhaus energy standards in the first test
In air pressure testing, the first home built using the TALO superstructure system at the Green Quarter in Bromley achieved 0.46 m3/hr/m2. This exceeds not just the minimum
requirements of 8 m3/hr/m2 set out in Building Regulations Part L1a and L2a (England and Wales) but surpasses the more stringent requirements of 0.6 m3/hr/m2 to exceed Passivhaus energy standards.
How have we achieved this? The dry timber approach (from sawmill and factory to site) and the use of advanced offsite manufacturing techniques significantly reduce air permeability to lower energy costs and improve overall performance of every home built using this system.
The attention to detail also extends to upskilling and supporting local trades to raise standards. Taking even more pride in their work and spending an extra hour on the finishing on site and we have proved that you can literally halve the energy bills for that home.
This is precisely why our focus is always on the outcomes – not just on helping housebuilders, developers and social housing providers build new low-rise homes.
