Lisa Grosse of Cedral discuss the impact the Future Homes Standard could have on current facade and roofing trends when introduced next year
Discussions around sustainability, futureproofing and a fabric first approach, which have been taking place across construction generally, have become increasingly prominent for housebuilding. Designing to achieve greater thermal efficiency will become more of a priority to comply with the new Future Homes Standard (FHS). This will require all new homes built
from 2025 to produce 75-80% fewer carbon emissions than present. While many architects, developers, contractors and manufacturers involved in residential construction have been proactive in making modifications to reduce carbon emissions, there is much more to do.
Energy efficiency & thermal performance
As many of the new FHS requirements specifically concern ventilation and energy use and for new build homes to be an efficient fabric, this has a direct impact on decisions about facades, roofing and insulation. Options for the facade include timber, stone, vinyl, metal, weatherboard, fibre cement, concrete and glass. Fire safety, aesthetics, durability, ease of installation, impact on thermal control and indoor air quality, acoustics and cost (both the initial expense and over the product’s lifetime) are all part of the equation. We often see a combination of materials on the facades of housing developments. A very large proportion of housebuilders, for instance, will use a render on the exterior of the ground floor and then a cladding material such as Cedral on upper floors.
One of the trends we are seeing for the exterior is more natural products such as fibre cement cladding. A strong, versatile and sustainable material containing cement and fibres, it uses fewer raw materials and less energy in its manufacture and produces less waste than some traditional building materials. When specifying, durability under extreme temperature changes, low maintenance and in particular, having an A2 fire classification rating, have been key and fibre cement cladding offers these benefits.
Optimising the performance of the roof is also central to the house’s energy efficiency as one quarter of all heat energy in a home escapes through the roof. Currently the Government is not mandating the installation of rooftop solar panels on all new homes, but it is logical to plan a roofing system that makes it possible.
For roofing, the most commonly available materials are concrete tiles, terracotta tiles and fibre-cement slates. There has been growth of fibre cement slates in the market because they are sustainable, have a good U-value, have an excellent fire classification, are lighter, and also for their aesthetics.
THE Options & benefits AVAILABLE FOR FHS COMPLIANCE WITH insulation
As a result of the new building regulations, new homes will have to be better insulated to reduce heat loss and mitigate against overheating. The question is whether to put the insulation on the outer or inner walls, and there are pros and cons of both options. For exterior insulation, boards are fitted to the outside of the walls, before covering the facade with rainscreen cladding such as timber, metal or fibre-cement weatherboards. The advantages of ventilated rainscreen cladding are that it increases energy efficiency, extends the lifetime of the facade, helps reduce condensation and humidity and helps reduce structural movement.
Typically for interior insulation, we see mineral or wool rolls being used in between wooden battens. With interior wall insulation, the finished building will keep a more stable interior climate, there is no impact on the external appearance of the house, it’s less expensive and it’s possible to use a wide variety of insulation material. The downsides are a loss of internal space and many types of insulation material require a fire-rated covering.
Some points to consider before making the final specification are the thermal resistance of the insulation method, the overall insulation gain, how fireproof and how safe the materials are, the expected lifespan and whether they can be easily recycled. Additionally, whether a property has a warm or cold roof, there are measures that need to be taken to ensure the long-term energy efficiency of the building. The key for roofers is to ensure that the ventilation in the roof space is well planned and constructed.
AN Increasing commitment to sustainability
Our research has shown us that people in various roles think about sustainability in very different ways. An architect, for instance, is very process-driven and concerned about metrics, performance, and ultimately accreditation.
RIBA’s most recent ethics & sustainability survey conducted in 2021, showed how a commitment to sustainability and low-carbon design had become even more important to its UK members, and how more homeowners are also thinking about the eco-credentials of their homes and about how to reduce their energy costs.
Now manufacturers have to address an increasing number of questions about sustainability with housebuilders and developers. They want to know where the materials have come from,
if they have a high ‘second use’ content, and how a facade will improve their carbon footprint.
We believe that advancements in sustainable construction will continue at a rapid pace, transforming home design. And manufacturers can help in the path to sustainability by improving circularity and environmental impact.
Lisa Grosse is brand manager at Cedral