Taking stock

The Energy Act 2011 proposes to make it unlawful to lease residential or commercial buildings with an Energy Performance Certificate rating of F or G from April 2018.  For new build residential, there is also a requirement for all new build to be zero carbon from 2016.

There is clearly a ramping up of the regulations and also the beginnings of a move from compliance with regulations at the design stage to performance in use.

The challenge, especially for landlords, relates in particular to the UK’s ageing property stock, not built for a world of high energy prices and carbon reduction targets, and lacking in investment in low carbon retrofit over time.

It wouldn’t be right to assume that all ‘modern’ property will achieve a good performance in use just because it has a good EPC rating. Even the highest spec builds with energy efficiency in mind may not be performing as expected. The limited research available has demonstrated that design targets (and we must remember that EPC is a design tool) are missed by between 20 per cent and an astronomical 500 per cent.  We must stop assuming that sustainability-minded design and construction methods are the whole story. Property needs to be monitored and evaluated for performance once occupied.  The introduction of co-heating tests will provide an assessment of a properties performance prior to occupation. Only then is it possible to gain a clear picture of the performance in use and learn for future designs.

With approximately 80 per cent of the properties that exist today still being in existence in 2050, the key issue for landlords in the run-up to the 2018 change is that they understand the scale, nature and cost of the various interventions that will be needed to update properties now. And that means learning in more detail about how properties actually perform in use.  A one-size-fits-all approach will not work and landlords will need to develop an evidence based approach, backed up with a robust whole life cost database for their properties.  Smart landlords will be using sensors to monitor energy use against temperature and other indicators such as relative humidity in order to identify more specific issues - so that they can identify whether the source of any inefficiencies is due to the building fabric, the equipment, the maintenance regime or the behaviour of occupiers.

Landlords also need to ensure that their design, delivery and maintenance teams don’t have a blinkered approach to energy efficiency and carbon reduction - as it is vitally important to ensure that the health of the fabric and the occupants are also considered. The existing stock of ‘leaky’ properties, whilst bad for energy efficiency, is good in terms of ventilation and here there is some distressing news from recent research that is showing that many - if not most - of the mechanical ventilation with heat recovery units installed in recent times are underperforming, which is seriously bad news for the occupants.

The property sector needs to move from making decisions based on capital cost and payback time to making decisions based on the ‘whole life cost’ as the primary decision-making tool, backed up by an assessment of the return on investment and importantly, evidence of performance in use.

Professor George Martin, Low Impact Building Centre, Coventry University, www.coventry.ac.uk