We ask the experts: ‘How does industry deliver net zero by 2050?’

Ahead of CIBSE’s Build2Perform event at Olympia, London, on 26-27 November, we asked expert speakers what should be done to achieve the government’s net-zero energy target

CIBSE experts

Clockwise from top left: Alasdair Donn, Justin Bere, Dave Pearson and Louise Hamlot

Alasdair Donn, head of building performance at Willmott Dixon

Meeting compliance targets ‘on paper’ is not good enough.

Delivering the UK’s net-zero target in 2050 means, as a design and construction industry, that from this point on we can only provide buildings that actually deliver on performance expectations.

Meeting challenging energy and carbon compliance targets ‘on paper’ may satisfy our customer and project energy requirements but, unless that translates to actual results, our UK net-zero emissions target is ‘toast’.

On new-build projects, we have to show what is possible and what is achievable – if we can push down designed energy use, combine it with renewable generation, and ensure no performance gap in use, we stand a chance of getting to that net-zero target.

Let’s embrace new ways of doing things such as Passivhaus, the Better Building Partnership’s Design for Performance, the UK Green Building Council’s net zero approach, BSRIA’s Soft Landings Framework, and Wilmott Dixon’s own Energy Synergy processes, to help get us there.


Justin Bere, director at bere:architects

The year 2050 is too late. We have to do this now in new buildings and in gigantic roll-out of retrofit. We need all buildings to be 100% electric, with an 80-90% reduction in energy demand so all the energy can come from renewable sources.

Passive House (PH) is firmly established as the best way to deliver net-zero and plus-energy buildings, and there is a small – but growing – group of PH experts in the UK that would be willing to run the necessary training to sort out our dire shortage of design and construction skills.

The obstacle is seen to be the price of net-zero buildings because most people and businesses can’t afford the upfront cost of major improvements or they want quick returns on their investment.

The solution is very simple: government-backed long-term loans so people and businesses do the right thing today for the long-term good. If retrofit or new work is done to a very high standard, I think people should be financially assisted where needed, to pay only for their period of occupation. This means a pension fund/government-backed charge being put on the building, with negligible monthly repayments that are far less than the energy savings, and paid back by whoever benefits from the improvements over a long payback period of 100-200 years.

Fast-forward 100 years and imagine people discussing the prevailing attitude today: ‘In 2020, they thought they couldn’t afford to stop wrecking the climate. Instead of fixing the problem, all they could think of was themselves, spending billions of pounds on new power stations which are now – in 2120 – already redundant, apart from a massive legacy of toxic waste they left for us to try to sort out, and billions of pounds spent, particularly by the richest people, on new cars, luxury goods, luxury overseas holidays and heating their homes.

‘Just imagine if those selfish people – in 2020 – had instead spent the same money on net-zero and plus-energy buildings that we could still be benefitting from now, all running off a renewable energy infrastructure. We’d have been happy to share the cost.’


Dave Pearson, director at Star Renewable Energy

Delivering net zero by 2050 will come down to many sectors.

There is plenty going on in electricity generation and transport, which is great to see. Heat is now widely acknowledged as a ‘key sector’ but, actually, very little progress is made. One could ponder why this is, but what about just getting it done?

There are five sectors in heat, where actions can be taken. And we should try to involve cooling in these too – they are after all, opposite sides of the same coin.

From the easiest to the hardest, they are:

  • New build low density: Ban gas boilers and don’t allow direct electric – this would alleviate potential stress on the grid.
  • New build high density: Join district heating, if it exists. If it doesn’t, pledge to do so, make the building district heating and cooling-ready (systems, temperatures and connections). In high-density areas – for example, central London – don’t try and make the development a ‘net-zero island’ as it makes adjacent retrofitting of energy networks harder with future ‘gap sites’.
  • Older low density residential: Force utility companies to offer ‘pay as you go’ heat contracts, then deploy heat pumps with local storage. This is the fastest way to grow our industry while acknowledging the reality that individual home owners won’t stump up large amounts of cash, even when it offers a return on investment. There should also be some sort of bonus for selling a house that has been retrofitted.
  • Older high density cities: Force all buildings to reduce emissions by 15% per annum (the real target ought to be net zero by 2030). If they can’t, let them agree to join district heating when it arrives.When there are enough pledges to join in an area of a city, the investment will flow. Note that investment must be in the right sort of district energy: durable, fairly priced and clean. An obvious solution copies the Norwegian city of Drammen, which has river- or sea-sourced heat pumps.If the building doesn’t maintain 15% per annum progress, serve a prohibition notice on use of equipment and remind owners the easiest solution is to pledge to join a district scheme. We call this a ‘fairopoly’, as everyone has to be fairly treated.
  • Industrial: many processes use steam when they could use hot water. Many processes simultaneously cool and heat. Join them up. If businesses won’t make the investment, force them to agree to an energy supply agreement and let them commercial suppliers carry the technical investment.Underwrite the consumer default with some form of credit risk sharing. For those processes below 150 degrees C, but above 85 degrees C, heat pumps are emerging to do this.

For applications above 150 degrees C, we should plan for the sensible use of high-temperature fuels such as hydrogen, biogas, biomass, and energy from waste.

It all begins with moving forward from gas and playing to stakeholders’ strengths and weaknesses.


Louise Hamlot, sustainability consultant at Elementa Consulting

To meet our climate targets, industry needs to tackle a range of subjects such as energy storage; demand response; performance gap mitigation; calculation methodologies; occupants’ education; low-energy systems; and passive design measures. However, a deep dive into each subject won’t be enough if we don’t tackle whole-life carbon emissions.

The industry has long focused on operational carbon – meaning ‘in-use energy emissions’ – but has ignored emissions related to the rest of the life-cycle stages of buildings.

Manufacturing and transportation, constructing, repairing and maintaining the building, and deconstructing and processing waste are all steps that create CO2 and other greenhouse gas emissions, referred to as embodied carbon.

Another important factor is refrigerant leakage, which has a high global warming potential and is often not considered.

Engineers, architects, contractors and clients need to understand the key levers to mitigate whole-life carbon emissions and get the full picture of their environmental impact through robust life-cycle assessment as soon as possible.

In order to achieve net zero for all buildings by 2050 all new buildings need to be net zero in operation by 2030. Leti and the UKGBC are running a consultation on the technical requirements for ‘operational’ net zero for new buildings.

They believe that the requirements must include an absolute energy meter target of 35 kwh.m-2 per year for residential, verification in-use, fossil fuel free on-site. Any energy consumption not met by onsite renewables should be met by investment in additional renewable capacity off-site.

See www.leti.london for further details.

For the full Build2Perform Live programme, and to register for the free two-day event visit www.build2perform.co.uk