BE was in attendance for this years headline act – so what did we talk about?
1. Overheating is…well…hot right now
Heat related deaths currently total 2,000 per year. This is set to rise to 7,000 by 2050 with the elderly especially vulnerable. We know that the current method of assessing overheating risk in SAP is inadequate. Higher levels of air tightness, inadequate ventilation and community heating systems are all contributors.
CIBSE updated us on their hotly anticipated new TM (Technical Memorandum) for new and existing homes which is in the final stages of peer review prior to publication. The new TM will build on the existing TM52 and CIBSE Guide A, which are very much directed at non domestic buildings.
It is clear that the London Plan is still setting the standard, already requiring developers to provide full overheating simulation using dynamic modelling tools, even at a very early planning stage.
2. The cost of zero carbon in London is a postcode lottery
We are already working on zero carbon schemes in the capital which require the developer to pay a minimum of £1,800 per ton of carbon (over 30 years) for anything they cannot offset onsite, but the local authority can charge what they like. The theory is that this money is spent on renewables projects elsewhere. Currie & Brown outlined the real cost variation across London, with Westminster topping the list at a whopping £7,500 per ton.
3. Investors have bought into sustainability
The money men in suits spoke glowingly about sustainable buildings, but they now have genuine good reason. They have pension pots to invest. L&G’s Dan Batterton told us, “We don’t want to build homes, we just want the asset”. They are identifying large scale residential schemes with low running costs and high yields and are especially focussed on the emerging build-to-rent sector.
Investors can encourage the speculative developers to take a longer term view – they are in a position to see out the full life of technologies & renewables. Sustainable, healthy and happy homes work for them.
4. Maybe we don’t need heating at all?
Berkeley boss Tony Pidgley casually threw in “Most of our homes now don’t need heating”. He is not the first to suggest it. We heard about the Passiv standard towers in Vienna with no primary heat source, and tales of London tenants switching off their heating for the winter whilst they enjoy the leaking heat from the communal hot water system.
5. Gas CHP is not the long term solution for zero carbon development
Decentralised energy, and more specifically CHP has been encouraged in the capital on new developments, but it is clearly not viable in the near to long term. The grid is being decarbonised at a rapid pace – the carbon intensity of electricity is falling and will shortly be reflected in SAP changes.
CHP is cost effective but not carbon effective. It also requires an ESCO market which has never matured so the developer cannot sell their excess generation, especially on smaller schemes.
Dan Epstein and his guests in the zero carbon arena reinforced the point that we can’t keep building high temperature systems – we have to move to low temp systems to take on new sources of renewable heat like ever more efficient (and viable in carbon terms) heat pumps. CHP heat losses have also been underestimated for some time.
6. We have to address ‘unintended consequences’
What is the trade off for high energy efficiency? Marcello Ucci from UCL told us that the when air tightness hits 3m3/hm2, house mite populations and mould growth significantly increase. But there is contradictory evidence.
Other studies have also shown that the higher the SAP score, the less associated mould growth. The same study showed that every unit improvement in SAP was associated with a 2% increase in asthma in children. Ventilation and air quality are at the root of most things, but much more research is needed.
7. The performance gap could fix our carbon budget
We know that the performance gap is somewhere around 25% – this is the difference between a design assessment (SAP, for instance) and the as-built performance. It is estimated, for example that some 40% of heat will leak into corridors and common areas from a typical community heating scheme. We know the problems but solutions are harder to come by.
We still have to meet the 3rd and 4th carbon budgets under the terms of the UK Climate Change Act. Imagine if we could close that gap and instead add that 25% to our carbon reduction?
8. Offsite construction has arrived to the mass market
So much so, that offsite construction enjoyed it’s own exhibition space this year. There is a growing recognition that traditional construction sites are not delivering the volume and quality of homes (in particular) that we need.
Modular, prefabrication, modern methods of construction – call it what you will – building homes in a dry, warm factory is quick, efficient and consistent. It also to some extent overcomes the dearth of skills onsite.
It is no longer a niche system for bespoke house builders. Berkeley’s Tony Pidgley told us about their Midlands factory which will soon be delivering modular homes to their Kiddbrooke Village site.
Offsite construction has hooked investors like L&G too, who see it as lower risk, quicker to site and well suited to the burgeoning Build-to-Rent market.
9. Health & Wellbeing is well and truly on the agenda
BRE detailed their new collaboration with the US based WELL Standard. A sure sign that they see each other as a threat! The folks at UCL were publicising their MSc in Health, Wellbeing and Sustainable Buildings. Investors told us that healthy, happy office space is top of their list and the lean towards corporate sustainability standards is driving new focus beyond energy.
10. Sustainability has moved beyond regulation
Dan Epstein said that he feels we’ve lost the leadership and focus we had 5 years ago. The Zero Carbon Hub has gone, zero carbon policy has gone, Code for Sustainable Homes has gone. We need leadership, and finance.
We are at a juncture where further regulation on new builds is delivering diminishing returns. We seem to have plateaued, so where do we focus? We have to drive performance, not compliance. Dynamic Simulation Modelling tools are crucial to closing the performance gap and going beyond energy. We need to completely and really understand overheating, daylighting and comfort.
11. Our clients need us to be BIM savvy
BIM was of course very well represented with its own stream of seminars. It is clear that the whole supply chain needs to collaborate for any value to be realised. This includes energy assessors and consultants like us, even if we are not building models.
Who knows where the tools will ultimately lead in terms of sustainability and energy performance, but for now we need to assist our clients and be able to extract and analyse data within a BIM model.