AIRCRETE AIDS THERMAL DESIGN BUT BEWARE OF A SHORTAGE Marcus Eves, Sustainability Consultant, Darren Evans Assessments


Marcus Eves 3The demand for Aircrete blocks has been steadily growing over the past few years. This can be thanked by a combination of the change in building regulations (Part L 2013) and a housing crisis that has led to strong growth in the residential sector.

With Part L 2013 putting more emphasis on the requirement of an even more thermally efficient fabric, through compliance with the Fabric Energy Efficiency Target (FEE) Aircrete blocks have become the preferred choice to achieve lower U-Values and better PSI Values (Thermal Bridging/heat loss at junctions) and an overall easier route to compliance.

The pace of the industry growth and a lack of raw materials have started to cause a shortage of Aircrete blocks, unwelcome bad news which is slowly rippling through the construction industry.

Pulverised Fuel Ash (PFA) is the main waste product from coal fired power stations and this raw material is integral in the production of most Aircrete blocks in the UK. This lack of material could similarly impact on other concrete blocks, cement and ready mix concrete as these products also use PFA.

A handful of factors have combined to see levels of PFA production drop. A mild winter has reduced the overall level of electricity generation in the UK, lower gas prices has seen electricity generators burn less coal and more gas and as we drive ourselves forward to a greener energy infrastructure reliance on coal power has diminished and will continue to do so.

There is potential to import PFA from coal fired power stations across Europe, but this has never been needed before so the transportation network and infrastructure just isn’t there yet. For now, the most important thing to do is be aware and plan ahead.

A change from Aircrete blocks to a denser block will ultimately see a rise in emissions through high heat losses through the walls and the junctions. This will cause some buildings to fail to meet the Emission and FEE targets, where previously the design assessment was compliant. Compliance with Part L can still be achieved with a change in blockwork as long as the assessor is informed early enough to propose ways to offset the additional CO2 and heat losses.

So the advice is to anticipate the shortage and to begin to design denser blocks into your SAP and SBEM calculations as early as possible.




englandDarren Assessments Ltd has donated two tickets to this weekend’s Euro 2016 warm-up football match between England and Turkey to a teenager battling cancer.

The tickets to the international fixture, taking place at the City of Manchester Stadium on Sunday evening, were made available to the teenager, currently in remission, and his father through Darren Evans’ close association with Children with Cancer UK, its 2016 charity of the year.

Darren Evans Assessments has supported Children with Cancer UK since 2013, beginning by donating a collection of Wembley Stadium tickets to the charity’s annual fundraiser ball. In previous years, additional tickets to highly-sought fixtures at Wembley Stadium have been auctioned off to the highest bidder, while corporate tickets for high-profile sporting fixtures have been donated to those directly affected by cancer.

Darren Evans Assessments’ Managing Director Darren Evans said: “We are pleased to have been able to provide a young cancer survivor with two tickets for this weekend’s England game. We are proud to support Children with Cancer UK in its efforts to help families and children through difficult times and also give some light and happiness directly to people facing truly difficult and challenging circumstances.”

Almost 4,000 children and young people are diagnosed with cancer every year in the UK. Dedicated to the fight against all forms of children’s cancer, Children with Cancer UK has raised an astonishing £150 million since it was founded in 1988.