Net zero in construction consultancy

1. Watch out for diminishing returns on fabric and insulation thicknesses
   The lower your carbon target, the more you get diminishing returns on fabric and insulation thickness.“There are curves of efficiency, at some point things become exponential, you might want to spend money elsewhere,” explains Brandon.“We are very good at finding efficiencies across the whole design. Space heating, hot water heating, passive solar design, fabric performance – we’ll look at the cost and impact on carbon emissions across all these things to help you decide what gives the best ROI.”
2. Embodied carbon is becoming increasingly important in England
   Embodied carbon refers to the CO₂ or greenhouse gas emissions associated with the materials and processes used in construction. It covers everything: extraction, manufacturing and transportation of materials; construction, maintenance and deconstruction of the buildings.“As buildings become more energy efficient and less energy intensive to run, the only carbon that remains is embodied carbon, which becomes a larger proportion of your overall carbon footprint,” explains Brandon.“Steel and concrete, for example, are very carbon heavy materials so it’s better to build by trying to minimise the use of those materials. There are robust alternatives to steel and concrete and these will become increasingly important.
3. The decarbonisation of the grid is reducing the carbon savings you can achieve from solar panels
   “Because the grid is decarbonising, carbon factors are changing in the new Part L regulations so the amount of carbon savings achieved from installing photovoltaics will be effectively halved,” explains Brandon.“This means generating electricity on a property is half as efficient from a carbon perspective because the electricity from the grid is much greener.“You still get a benefit, especially in energy, but the carbon savings are less. This makes electric heating and heat pumps twice as effective. You can’t just whack a bunch of PVs on a building and get the same result as you did before.“Air source heat pumps are where it’s going. In 3-5 years, heat pumps will replace all gas boilers. Regulations are going to require it,” says Brandon.

The Climate Change Act 2008 requires the UK to ensure that its net carbon account for the year 2050 is at least 100% lower than the 1990 baseline.

To ensure that the UK construction industry is on track to meet this target, in 2019, the government launched The Future Homes Standard consultation. This proposes changes to Part L (conservation of fuel and power) and Part F (ventilation) of the Building Regulations for new dwellings.

The first change is set for 2020, although this has yet to be confirmed. The second, more radical changes, are scheduled for 2025.

For the 2020 changes, the government has said it favours the “fabric plus technology” solution, which is intended to deliver a 31% improvement on the current standard.

In practice, this means a minor increase to fabric standards – double rather than triple glazing, for example, alongside the use of low-carbon heating and/or renewables, such as photovoltaic panels.

By 2025 the government expects an average home built to the new standards will have 75- 80% less carbon emissions than one built to current energy efficiency requirements.

Heat pumps are set to be a vital part of achieving this fall in emissions.Get in touch

1. Confirm and define your targets and goals: for example are you aiming to meet Passivhaus standards, or net-zero ones? If net-zero, will you be including embodied carbon in your calculations?
2. Sense check what’s possible: we can support you to review the current proposals and make sure what’s proposed is achievable.
3. Create models: again, we can support you to tweak your designs and create models to show how the goals can be achieved in practice.