Designing an energy-efficient home has never been more important, says Joseph Raftery.
Today, our society is grappling with the complex challenge of building sustainable homes, that focus on the long-term whilst being cost effective and refusing to compromise on aesthetics. It is no mean feat but it also presents a unique opportunity to really educate ourselves about the best options available and to share the knowledge we do have that will reduce carbon emissions in housing whilst improving living conditions.
On the journey to achieving net zero homes, and being especially mindful of meeting the Future Homes Standard of 2025, which will rule out fossil fuel heating in all new build developments, there has been much discussion over the last few months about low-carbon heating options, and in particular heat pumps. In the UK, we will need to phase out oil and gas heating systems like boilers, replacing them with low-carbon technologies. These systems can help to reduce carbon dioxide emissions from households.
So what does this mean for architects?
In our business, we always say to anyone designing a low-carbon home and installing technology such as heat pumps, that there is one golden rule. For new build developments, it is essential to incorporate low-carbon heating into the design process from the outset. Heat pumps for example, work best and most efficiently when included in a design from the beginning as part of the conceptual and functional utilisation of the new home.
As architectural designer and brand ambassador for Samsung heat pumps, Charlie Luxton, points out: “The key thing is to start off with is a design that reduces energy demand and then meet that demand with a low-carbon option, which realistically is low-carbon electricity and heat pumps. It is important to think about the energy consumption both in construction and occupation. In my architectural practice, we look a lot at thermal modelling to optimise solar gain and minimise over heating. Being energy efficient as an architect means a lot of insulation combined with airtightness and optimising for solar gain whilst mitigating against overheating to drive down heating/cooling and lighting requirements.”
On older homes using a low temperature heat pump, there may be a need to replace radiators based on their condition and heat output at water flow temperatures of 55 degrees Celsius and below. Contrary to what a lot of people think, this does not mean extensive work is needed. In many cases changing single panel radiators to a double or triple radiator will give the room the same comfort level at lower water flow temperature (e.g. 45– 55 degrees Celsius) which is a more efficient way of heating the home.
For any UK home that has a heating system designed to UK Part L 2014 standards (Building Regulations that require a maximum water flow temperature of 55 degrees Celsius), it should be a simple change. Alternatively, a high temperature heat pump such as the Samsung EHS Mono HT Quiet enables the switch to low-carbon heating without switching to a low temperature system which can ease the transition for the end user.
Of course, the other critical element to remember is insulation. All homes need to be as well insulated and as draught-proofed as possible for the heating system to be effective and efficient.
What is important to the house owner or tenant when it comes to energy efficient homes?
Three major concerns in any build are affordability, design and operability.
Let’s take affordability first. There are grants available to homeowners from the government’s Boiler Upgrade Scheme. The advantage of installing a much more efficient heating system speaks for itself. A heat pump for example will heat the home, the hot water and be 500% efficient, compared to an average of 92% efficiency for gas heating systems when properly maintained.
This means that typically for every Kw put in at the ambient air temperature of 7 degrees, which is an average climate for the UK, you would expect to get around 5Kw thermal output to heat your home and hot water. In the industry, this is known as COP (coefficient of performance). In simple terms, the heat output is more than the electricity input, meaning a heat pump can increase the energy efficiency of any home.
In terms of design, the latest air source heat pumps are sleeker and more aesthetically pleasing than ever before, allowing them to become a feature of the domestic home without disrupting the design. For example, the latest Samsung EHS Mono HT Quiet heat pump comes in a matte black design. Heat pumps can be incorporated into the home in a variety of ways depending on the end-design vision such as in the garden, floor-mounted on an exterior wall of a property, or if space allows the unit can be mounted on a wall. The outdoor unit can work well on certain roofs with enough flat space, allowing the pipework to go straight down to the tank inside the house.
Operability and installation is often a concern for both architects and home owners. We often speak to people who want to embrace low-carbon heating but need information as to how they work and how to ensure quality installation. Architects should work closely with experienced and knowledgeable installers. Air source heat pumps are actually very easy to install and use when done so correctly, training is widely available and will ensure a smooth running experience to the build.
The heat pump market in the UK has grown by 64% from 2020 to 2021. We are witnessing an evolution of consumer demand and an attitudinal shift in the way we view our domestic heating in the UK. Ultimately, incorporating low-carbon, energy efficient heating into UK houses is a fast growing and important opportunity for architects. Heat pumps are a technology that is proven effective, supported by an experienced industry with good levels of government backing.
