The Government released major updates to Part L of the Building Regulations, Conservation of Fuel and Power and Part F, Ventilation, at the end of last year.
It also introduced a new Part O of the building regulations, which is designed to prevent over-heating in newbuild homes and other residential developments.
Changes to all three regulations come into force in England from June 15thThe links to each approved document are below. While we’ve summarised the key points, we’d recommend that you make yourself a strong coffee and sit down and take time to understand them.
Our homes leak masses of energy every year, accounting for around 14% of all emissions, so improving the energy efficiency of housing, including retrofit, is key.
The Future Homes and Building Standard (the new name for the Future Homes Standard since December 2021), is the Government’s roadmap for delivery - and tighter building regulations are how it’s going to do it.
The first big target is 2025, when newbuild homes will have to produce 75-80% fewer carbon emissions.
The targets, however, also apply to retrofit and home improvements as part of a target to cut emissions from housing as a whole by around 30%.
Well, the answer here is ‘no’ and ‘yes’ (or should that be the other way around?). Part L is about making new build and existing homes more energy efficient.
At the same time Part F says we need to make sure that there’s a constant level of background ventilation - which negatively impacts thermal performance.
New homes can be designed to deliver both. But things are more complicated, particularly in window and door retrofit, because we’re sealing up homes that weren’t meant to be sealed up.
That creates a raft of health problems - mould, damp, respiratory conditions – so it’s a trade-off. We need to raise the general level of thermal performance but maintain background ventilation, which is why trickle vents are here to stay!See what the GGF has to say about Part L and Part F here
Part L sets standards for energy efficiency and carbon emissions of new and existing buildings. This means that it applies not only to new build properties but also home improvements, including windows and doors.
The Government has a target to hit net zero by 2050. To get there it needs to make homes more energy efficient, including those that we already live in.
From 15th June 2022, changes to Part L introduce new requirements for enhanced thermal performance in windows and doors as follows:
Notional u-values apply to new build with windows and doors carrying a notional value of 1.2W/m2K. Notional u-values are a ‘recipe’ book for developers. Take windows with a u-value of 1.2W/m2K, add in roof insulation to ‘X’ and wall insulation to ‘Y’, and you’re going to meet requirements for Part L.
What you can also do as a developer is to decrease the notional u-value of one of those elements, as long as you increase it in another area, so the end result – the overarching energy efficiency of new homes – is still on target.
In practical terms this means that a developer could specify a window with a notional u-value of 1.3W/m2K, not the 1.2W/m2K notional u-value, and still comply with Part L of building regs.
Notional u-values mean that developers have a little ‘wriggle room’ but there is still a line that they can’t cross, and that’s the ‘Limiting value’.
For windows and doors this is 1.6W/m2K. It doesn’t matter how ultra-energy efficient other elements of your development are. Windows and doors still have to be a minimum of 1.6W/m2K.
For a more detailed explanation click here.
Although there is a 12-month transition period for new build, new regulatory requirements under Part L come into force with immediate effect on the 15th June 2022.
It’s fine. You can relax and take a breath. Conservatories are exempt under regulation 21 of the building regs as long as all of the following apply:
Part F sets out the requirement for ventilation in buildings, including new and existing homes, focussing on air quality and the replacement of old stale air with fresh air. It’s intrinsically connected to Part L and is designed to make sure that while we improve the energy efficiency of our homes, we balance it against a requirement for fresh air.
Approved Document F sets out three routes for compliance. This includes System 1, ‘background ventilation’ i.e. trickle vents; System 2, continuous mechanical extraction; System 3, mechanical ventilation with heat recovery and no background ventilators.
System 1 in Part F – background ventilation – is one of three options, which housebuilders can put in place to make sure habitable rooms are properly ventilated.
Windows and doors have a key part to play in doing this, and that means that unless another system is in place, new build windows will need to be supplied with trickle vents.
What does EA stand for in ventilation?
EA in ventilation stands for Equivalent Area. This is a measure of how much air passes through a vent as a measurement of airflow performance.
Are there any exemptions to Part F at all?
Ok – there are one or two exemptions to Part F (and Part L), mainly connected to listed building status and conservation areas, in which case exemptions may be applied for to not fully comply with the regulations in line with A7 to A13 of the Manual to the Building Regulations:
Our Part F solution
Trickle vents are here to stay. We’ve searched high and low and found what we believe is the most competitive, practical – and best looking option on the market – and that’s the Link Vent from Glazpart.
This means that our trickle vent options available in 5,000, 4000, 2500 and 2000 EA, plus a choice of 20 different colours and finishes, providing a perfect match to our foils range.
We’ll let Glazpart explain:
Does the ordering process change?
From June 15th when you order new windows and doors you’ll be prompted to specify trickle vents. We can’t tell you what to specify because we’re not carrying out the survey, so that responsibility sits with you – but we will remind you to do it and can offer you access to the industry’s leading trickle vent offer.
We’ll give the final word on Part F and L to our Sales director Emplas but in short, we’ve got you covered!
Approved Document O is new and is singularly focussed on preventing the over-heating of homes in summer through solar gain. Like Part L and Part F of the building regs. it sits within the broader framework of the Future Homes and Building Standard. As it’s new build only, we’re not going to drill down into the detail here, but essentially it sets limits for the allowable area of glazing dependant on orientation. It also divides the UK into different areas of risk.