Opinion piece by Neil Freshwater Director at Active House UK & Public Affairs Manager at VELUX

Modern ambitions to make our properties more energy efficient can perhaps be traced back to 2001 one with the creation of the Energy Performance of Buildings Directive (EPBD) which first introduced the need for Energy Performance Certificates (EPCs). This set the benchmark for making our buildings more energy efficient and over the past 20 years moves have been made, at varying pace and with checkered success to make both our new and existing buildings more energy efficient. The latest stage in this journey is the UK government’s Future Home Standard for England (which despite its name its name is not a standalone standard, rather proposed changes to the building regulation Approved Documents relating to energy efficiency, ventilation and prevention of overheating). The devolved nations have been taking a similar approach too. However, with this focus on energy efficiency there is a need to consider human health and indoor comfort. This is where Active House and the Active House Alliance comes in.

The global Active House Alliance was launched in 2011 following a number of pilot projects around the world such as those pioneered by one of the founding members, the VELUX Group. These buildings were then monitored the indoor comfort to see how they performed, once the occupants had moved in. The findings from this helped to develop the Active House standard as we know it today.

So what is an Active House? When we buy or rent a house today, we know certain things about it such as how many rooms it has, how energy efficient is it and how much it costs to run. But do we know how good the daylight is, the environmental impact of the construction materials or the quality of the indoor air? Given that we spend 90% of our time indoors and we now that these things can have an impact on human help it is important to know these sort of things, and to optimise them when we design or renovate a property.

At the heart of the Active House is the radar, and this is a simple chart that scores the quality of nine parameters across three categories in accordance with the Active House 3.0 specification.

Indoor Comfort: daylight, thermal environment, indoor air quality, and acoustic quality
Energy: energy demand, primary energy performance, and energy supply
Environment: sustainable construction and fresh water consumption.

Active House does not operate on a pass/fail basis, but rather it seeks to quantitatively score each of these aspects, either at the design stage or in a finished product. A range of 1-5 is used, with 1 being the best score (outermost) and this is represented on an Active House radar which is the means for visualising the performance :

Depending on the project in question, the Active House radar software allows a benchmark to be entered (light green area) which will be the minimum legal requirements (new build) or the existing building performance (renovation), and the darker green area showing the post-build/renovation score.

For some projects, a client will want the project to be verified and a project once complete can be externally verified and provided in meets minimum overall scores, the project can be awarded an Active House Label.

Guidance is provided to a designer as to how to maximise each of these elements based on the aspirations of a project or the requirements of the project client.

The benefit of designing to Active House specification

As mentioned above, it is important that we take an holistic approach to designing and renovating buildings, that considers not only energy use but also human health and the environmental impact.

From an energy perspective Active House encourages the use of low carbon energy sources that are easy to use, optimising energy efficiency above statutory minimums and a reduction in energy demand.  

For indoor comfort and health, this means ensuring that the building optimises natural lighting with suitable shading to prevent overheating and glare; that ensures good air quality through natural where possible, or mechanical ventilation; that limits unwanted noise from the building and provides acoustic comfort, and a building that provides excellent thermal comfort.

From an environmental perspective, sustainable construction is encouraged through the use of natural or recycled materials, materials certified with EPDs or FSC/PEFC in the case of timbers, and lower environmental loads.

The better the use of the above, as outlined in the Active House Specification, the higher score that a building will achieve in each of the categories.

New-build and renovation

Active House can be applied to both new buildings and buildings that are renovated or extended. The criteria remains the same, but the difference is that where the building wishes to be verified as an Active House, a new build must achieve a better overall score than a renovation. Active House can play a key role in the progression of our climate change ambitions as we seek to renovate the existing building stock by making sure that as well as energy efficiency, we also consider indoor health and comfort and don’t end up with any unintended consequences such as not ventilating buildings when we make them more airtight.

Active House UK

The UK chapter of Active House was launched in 2022, over a decade since the global Alliance was formed. It is run as a not-for-profit association is very keen to engage with architects, manufacturers, builders, academics or anyone else with an interest on holistic building design. Come along at visit our session at futurebuild on 7 March, 2pm-2.45pm or visit www.activehouse.uk.