Energist - Part L Compliance Experts - Blog

It’s becoming quite clear to us that there’s a big buzz in the industry around the idea of building to the PassivHaus standard. But what does that mean? Here’s a quick run through:

PassivHaus is a way of measuring the heat loss of a building (domestic or commercial, old or new) with the aim of maximising efficiency through insulation levels and air tightness – the first PassivHaus was built twenty years ago in Europe, but the idea is only now filtering into the UK.

We would expect a Passivhaus to record an air leakage result of less than one. Current new build houses in the UK are achieving around the 6-7 mark… U-Values of a PassivHaus wall would be less than 0.15 – half of what is typical in the current market… Mechanical ventilation and heat recovery systems tend to be fitted as standard… all of this combined pretty much eradicates the need for a heating system, (although don’t quote us on that given Blighty’s climate!)

The process of completing a PassivHaus calculation has similarities to the mandatory SAP calculation in the UK, an Accredited piece of software must be used to record U-Values, efficiencies and air tightness. Whereas SAP records a total emission target for a building, PassivHaus is based on the overall energy demand.

If you’re tempted by the idea of building to PassivHaus standard, you need to remember that this practice is only voluntary in the UK, but the SAP assessment is mandatory! And despite having some similarities, it can be incredibly difficult to design a building which meets all the aspects of both SAP and PassivHaus combined!

The assessment team at Energist is able to help you with PassivHaus queries, offer consultancy sessions and even complete the PHPP assessments. Or, if this has scared you off the idea of PassivHaus and you just want to stick to current Building Regs, we can provide a Guaranteed Pass on all new-build SAP assessments!

Call 08458 386 387 for more information.

THIS WEEK, TENS of thousands of professionals from the European building industry attended the EcoBuild exhibition at Earl’s Court to gain an insight into the latest developments in building materials, renewable technologies, heating systems and building legislation.

So what did the Energist team uncover in among the thousand plus exhibitors and scores of seminars?

“EcoBuild was launched 5 years ago, and the attendance was 950 visitors in the first year.  This week, the 2010 EcoBuild had over 55,000 visitors, with 25% more exhibition space than 2009.  This surely demonstrates the size of the green and sustainable market – which gives us a glimpse of a no doubt challenging but also exciting future” Sarah Fenwick, MD, Energist UK

-          There was a heavy ethos on PassivHaus among developers and accreditors. This is despite there only being a handful of live projects currently on the go in the UK. PassivHaus is used more widely in Europe as an alternative way of gauging energy efficiency in buildings, with the emphasis on air tightness and insulation to keep heating costs to an absolute minimum. If you would like more information on PassivHaus developments, call us for more information.

-          Mechanical Ventilation systems – which channel warm air from wet rooms, filter it and recirculate around the rest of the house – have come on leaps and bounds in the past couple of years. Again, the benefit here is a more constant internal temperature and higher air tightness; although there are murmurs that developers are not convinced that these systems are being used correctly by the people who live in the houses, causing the dwelling to be less efficient.

-          Plenty of building materials and insulations on show from polystyrene blocks to walls made of hay and hemp. This can be a confusing juggling act for those responsible for sourcing materials for building… is it cost effective? Does it have a good conductivity? Are the materials sustainable? Do they degrade over time? Can it be damaged easily? How will it effect the SAP and SBEM calculations? We’d recommend putting plenty of research into new construction methods if you haven’t used them before to make sure they’re appropriate for your site.

-          There are plenty of bodies out there eyeing up the future of Building Regulations in the UK. Short term, the SAP Calculation is going to get tighter (starting with a 25% emission cut from October) with the ambition that all new build dwellings are carbon neutral by 2016, and all commercial buildings by 2019. And then the longer-term plan is to turn our attention to the existing housing stock to see how we can cut our emission rates even further.

What thoughts did you come away with from this year’s Ecobuild? We’d love to hear them!

Remember that Energist can help with Air Tightness Testing, SAP and SBEM Calculations; Code for Sustainable Homes, Energy Statements, PassivHaus, Sunlight Feasibility Reports, BREEAM, Commercial Energy Performance Certificates, Display Energy Certificates, the list goes on…. Call us on 08458 386 387 to find out how we can help you meet your Part L sustainability needs.

PassivHaus originated in Germany where the 1st PassivHaus was built in 1991. PassivHaus is a standard for energy efficiency and PassivHaus buildings have very low energy use.

Unlike the Code for Sustainable Homes, which focuses on reducing CO2 emissions, PassivHaus is about reducing energy demand and is becoming a common building standard throughout Europe.

At Energist we have a team of fully qualified Energy Assessors who can guide you through the PassivHaus process, from initial building design to final certification. We can also provide technical advice and training on all aspects of PassivHaus.

For more information on PassivHaus and how Energist can help you achieve compliance call us on 08458 386 387, or email info@energistUK.co.uk or check out our website www.energistuk.co.uk/residential/passivhaus