Necessity For Zero Carbon Buildings - HPA

Necessity For Zero Carbon Buildings

The Committee on Climate Change have just published their much anticipated ‘Net Zero’ 2019 report, providing a map for how the UK can tackle climate change, and how we can have Net-Zero Greenhouse Gases as early as 2050. The report highlights a number of areas where these efforts need to be focused, with one of these being the construction industry.


The technology already exists for construction industries meeting this tough – but achievable – challenge. As architects, we have already used a number of techniques and systems which the report recommends using. Here are some tips on what we’ve learnt from our own research and development into sustainable architecture, over the last few years:


The first step is to insulate the building, so it retains heat during the winter and keeps cool during summer. It’s the most cost-effective way to reduce energy, in order to keep your building at a comfortable temperature.

Insulation regulations have changed a lot over the past 10 years. For instance, in the late 1990’s, wall insulation thickness in a new home was typically 25mm thick, compared to 100–150 thick under current regulations (using PIR Insulation). There’s always room for improvement, however, and the insulation requirements in Building Regulations will need to be upgraded further if we are going to meet the 2050 climate change target.

At the moment, increasing insulation in houses is voluntary. As a practice, we do talk to our Clients during the starting stages, to persuade them to allow us to exceed current regulations and create a building which uses less carbon. Not only is this an ethical decision, it is also one which will make the building cheaper to run. Finally, choice of insulation. A moral choice is to use natural insulation such as sheep’s wool. This product is becoming more widely used and comes from a sustainable source.


Heat pumps are electrically-powered systems, best described as a refrigerator acting in reverse. The efficiency of systems has improved markedly over the past few years, making it now possible to retro-fit Air Source Heat Pumps into existing houses with conventional, convector radiators. These units will become more mainstream over the next few years.

We’ve used Heat Pumps on a number of projects, whether it be Air-Source, Water-Source, or Ground-Source. The feedback we’ve had from Clients has always been positive, and they do seem very cost effective to run compared to oil or gas – especially if used in a building fitted with Photo-Voltaic Panels.

Solar Thermal Panels are a proven way of heating hot water during the summer. At other times of the year, the panels can partially heat the hot water tank, leaving less work (and energy) for the main heating system to bring water to the desired temperature. Of course, you can make your existing heating system a lot more efficient by insulating your house to reduce the amount of energy you need to heat the property in the first place!


The efficiency of appliances and lighting has improved greatly over the last 20 years, so much so that the technology now exists to run a household using surprisingly small amounts of power. We’re working on an exciting sustainable architecture project at the moment with a client who wants to power a house using ordinary network cable. The house is lit by LED lights and uses 12v DC current to power all the household appliances.

The electricity is provided by Photo-Voltaic Solar Panels, with excess power being stored in a battery; the property is effectively off-grid. This technology is improving all the time, and we expect to see massive advances over the next few years. Continuing improvements in the efficiency of household devices will help to lower electricity consumption for dwellings, making a huge difference to each home’s carbon footprint.


A Government Survey in 2015 found that over 75% of UK houses were built before 1980, and 24% were before 1919. Seeing as insulation standards have only increased dramatically, figures demonstrate that there are houses out there which don’t meet current standards. If the UK wants to commit to being zero carbon by 2050, then these older buildings are going to need attention too.

We have had experience of retrofitting older houses, adding insulation and energy efficient heating systems, but still retaining original building character. Recently, we helped to bring a Victorian House up from a ‘F’ rated EPC to a ‘B’ rating. The owner of the property has already fed back to us that their heating bills have reduced dramatically!

These measures can also apply to Historic Buildings. We recently worked on a Grade II Listed Church, where Photo Voltaic Panels and a highly efficient Air Source Pump Heating System have been discreetly fitted to power and heat the building. The Church has reported they now generate virtually as much energy as they use. The Air Source Heat Pump is not only significantly cheaper, but it can also keep the building at an ambient temperature during winter outside service times, which is great for preserving and maintaining the building’s fabric.


The last time there was a major improvement within Thermal Requirements in Building Regulations, the standards were quickly accepted as the ‘norm’. Therefore, they need to change again, if the government want to make this an accepted mainstream occurrence.

We therefore welcome the report’s findings, along with the challenges it sets. At HPA, we regularly use techniques and technology to help move our country towards the virtually zero carbon goal. But at the moment, only some Clients choose to voluntarily surpass levels for energy efficiency set within Building Regulations.

If you are designing or upgrading a building and you want to make an immediate difference straightaway; make sure you over insulate!

Written by Richard Wooldridge, HPA Director

To explore our range of housing sectors, click here – or to read more about HPA’s sustainability building design, click here.

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