What does this mean for you?
Last year, Part L building regulations changed to introduce an interim uplift. The new measures require any new and existing buildings to deliver a higher standard of energy performance and a reduction in carbon emissions.
June 15th 2023, sees the end of a year-long grace period, which was granted to ease in the new standards and completion of work under the old regulations. Going forward, any buildings constructed must now meet the new Part L building regulations. So, what do these changes mean for your project and how will it impact your choice of build material?
Why the Changes to Building Regulations?
Climate change is a growing problem within the UK that is resulting in severe and dangerous weather events. In a bid to tackle this the Government wants to position itself as a global leader in environmental policy and has set an ambitious target for the UK to achieve Net Zero by 2050.
When you consider that heating homes and workspaces accounts for almost a third of all UK carbon emissions, making changes to the built environment has formed a crucial part of their planning. The changes to the building regulations are a forerunner for the introduction of the Future Homes and Building Standard in 2025. These additional changes will require buildings to produce 75% to 80% fewer emissions.
Take the Fabric First Approach with Part L
Building with a fabric first approach has for a long time been considered an effective way of creating energy efficient homes. It is therefore unsurprising that the methodology behind fabric first features heavily in the Part L changes.
An insulated solid wall construction method like ICF prioritises these approaches. Through its structure, the system can improve the thermal performance of your building and minimises the need for heating and cooling. ICF addresses five key areas in the specification: insulation, u-values, airtightness, thermal bridging and comfortable living environment.
With Increased Insulation the formula is quite simple, adding more insulation will increase the energy efficiency in the home and thereby reduce carbon emissions.
U-Values indicate how much heat is lost through the thickness and insulating properties of the material. The lower the U-value the better the thermal performance.
The recent changes to Building Regulations Part L have increased the requirements for building materials. The limiting U-Value standards for an external wall have reduced from 0.30 to 0.26. However, it is worth noting that these are the maximum permitted levels allowed. Achieving them may not be enough to meet overall compliance during testing and you may need to offset elsewhere in the specification. It is therefore advisable to design to the notional value of 0.18 or better.
Airtightness is key to delivering energy performance by preventing heat from leaking through gaps and cracks in the external envelope. In the new regulations, air leakage can be no more than 8m3/h/m2@50pa with a notional standard of 5m3/h/m2@50pa. Achieving high levels of airtightness very much depends on the construction method.
Thermal or Cold Bridges are weaknesses in the thermal envelope of a building. These allow heat to pass to the outside via a material that is more conductive than the ones around it. Thermal bridges usually occur when there is a break in the insulation. It is also a major cause of condensation and mould. Avoiding these areas will significantly increase the energy efficiency in the home.
Meeting New Part L Building Regulations with ICF
Considering external walls typically deliver one of the largest surface areas in a property they should be a key area for any developer to address when working towards the new Building Regulations. When building with an insulated solid wall construction method like ICF, the insulation levels are built in.
Two facing layers of an insulating material (either EPS or Woodcrete) form the shape of the block. The blocks quickly stack on-site without the need for an intermediary bedding material like mortar to create the wall structure. Concrete is then poured into a central cavity and, once cured, the blocks remain in place to deliver a wall of insulation that wraps the building both inside and out. Within the array of ICF supplies, there is a selection of product solutions available that can easily deliver U-Values of 0.18 or better.
It is the build process that enables ICF to deliver its superior levels of thermal performance. The blocks lock tightly together so they can hold the wet concrete in place. The concrete then sits in direct contact with the insulating material to create a continuous and unbroken surface. This enables ICF to deliver airtightness levels from 3m3/hr/m2 or lower and virtually eliminates thermal bridging.
Overheating
Although we have mainly looked at Approved Document Part L it is also worth considering the introduction of Approved Document O. This is a new inclusion to the Building Regulations which aims to prevent overheating in properties.
The new document addresses the role of glazing in a building to reduce overheating. However, your choice of build material can also help towards this. ICF structures have superior thermal properties. The solid concrete core has a high storage capacity with low thermal conductivity. This enables the walls to absorb external day-to-night temperature fluctuations and slowly release them internally. This stabilises the temperature and enable the building to remain cool in the summer.
Interested in building with ICF?
This year a full technical consultation begins on the next stage of the Future Buildings Standard before it comes into effect in 2025. It is expected that any changes will increase energy performance standards even further. If you want to start working with a construction method that is ready to meet and exceed the current standards, then email us at hello@icfa.org.uk or contact us.
