Reducing existing homes carbon footprint

How to reduce your home's carbon footprint

Category:

The Built Environment

Tags:

enerphit, sustainability, passivhaus

The construction sector is one of the biggest contributors towards greenhouse gas emissions, with buildings in the UK accounting for more than 40% of all carbon emissions. In recent years, energy has become a key consideration in the way buildings are designed due to trepidations over climate change and carbon emissions. In simple terms, a carbon footprint is the amount of carbon dioxide pumped into the atmosphere as a result of the actions of people, businesses and organisations. The car industry has made great strides with the introduction of electric cars that have a fraction of the carbon footprint of petrol and diesel cars. In the UK of late, the large majority of progressive property developers are now embracing sustainable design and as a result build systems that minimise ecological, environmental and wider global impact. “Eco homes” are experiencing an upward trend not just in the UK but around the world. Thanks to advancements in technology, it is now easier to increase the energy efficiency in new buildings and renovations without compromising on the aesthetics, security and comfort. Passivhaus and EnerPHit Passivhaus design is a standard for sustainable housing that aims to create a new-build home that maintains a comfortable ambient temperature with minimal energy use. This is done by utilising passive energy sources such as sunlight, human and appliance generated heat to dramatically decrease the need for additional heating. Therefore the goal of Passivhaus standards is to reduce carbon footprints by producing a high level of air quality and thermal comfort using as little non-renewable energy as possible without a compromise for occupants.  It paves the way for encouraging concepts such as zero carbon homes - a great approach for green building design and construction. EnerPHit is a certification scheme developed by PHI for approved energy retrofits, which use some of the Passivhaus components. Zero Carbon Homes Zero carbon homes produce zero or negative CO2 emissions by maximising the use of energy efficiency and renewable energy. Emissions are significantly reduced through energy efficient heating and cooling technologies. There are flexible and scalable zero carbon housing solutions readily available in the market; flatpack modular houses that can be customised and created from cutting-edge technologies and recycled materials. Atelio, a modular zero carbon housing developed by a team consisting of Grimshaw, SAM Architects, manufacturer Tufeco and the Carbon Free Group was launched last year, with sustainability at the forefront. Composite materials such as recycled glass are engineered into panels that are used for walls and the roof which require minimal labour or specialist equipment to build with. Each Atelio building is rated zero energy due to renewable energy systems built into and around the house. Approaching climate change is not as expensive as initially assumed – Atelio houses can be purchased for around £500k with a turnaround time of just 4 weeks. Atelio - example flatpack and interior The amount of energy one uses in their home is having an adverse impact on the environment. Even more so if it is a poorly insulated Listed or characterful historic building. The domestic housing sector is responsible for 17% of the UK’s CO2 emissions and 29% of the UK’s energy consumption. The planet’s resources are being depleted at an exceedingly quick pace. A life without fossil fuels is fast approaching so energy efficient alternatives must be available before then. Secondary Glazing In major towns and cities in the UK such as London, the concept of hydroelectric generation or wind turbines is often unrealistic due to how built up urban areas are.  Reducing non-renewable energy use at home is a sure-fire way to reduce carbon emissions. In order to achieve high levels of insulation, installing very high performance windows with an airtight building fabric would reduce energy costs. However, due to the Listed status of many building across the UK, the replacement of primary windows is not possible. There are also some building owners who choose to retain the character of their original windows, which would need potentially need upgrading. The insulating properties of glass is inferior to walls, hence energy consumption increases proportionately to the glazed area. Therefore, excessive heat gains and losses in Listed buildings can be offset by high performance secondary glazing systems. Systems are retrofitted to the room side of the building and are a fully reversible adaptation, so widely accepted by heritage bodies. In order to optimally reduce a home’s carbon footprint and heat loss problems, the glazing installed must have low U-values for both the glazing and the frame. The introduction of secondary glazing traps an insulating layer of air, which can reduce heat loss by up to 50%. With the introduction of low emissivity glass, U-values of around 1.8 W/m2K can be achieved. Air leakage can significantly increase the space heating requirement of a dwelling as well as cause localised discomfort due to draughts. However, the use of high performance twin seals on the units help to virtually eradicate them.  This modern insulation technique can assist with a home looking to achieve Passivhaus/EnerPHit standards. EnerPHit is the quality standard awarded by the ‘Passivhaus Institut’ to a deep retrofit of an existing building which meets a specific criteria. An additional benefit of secondary glazing aside from its energy saving properties is that it reduces sound transmission from the exterior of a building. Aside from insulating and adequately sealing your home with measures such as secondary glazing, it is recommended to incorporate effective insulation in a property’s loft, around the water tank and in wall cavities. This can stop around 35% of heat produced in a property from escaping. Instead of leaving electrical appliances on standby as they can use a surprisingly high amount of energy, turn them off at the wall when not in use. When it is eventually time to replace an appliance, consult the Energy Saving Trust’s guide. Also consider turning off radiators in rooms that are not being used.  Switching energy supplier to one that supplies through renewable sources can also reduce the amount of C02 emitted per unit of electricity. The installation of solar panels requires a level of investment but if they are an option they are a useful power source that will make a huge difference to your energy efficiency and environmental impact.  Opting for LED lights is an energy saving alternative that require just a fraction of the energy absorbed by metallic bulbs. Whether they are wholesale or small changes to your domestic setup, the innovations and recommendations above can make a big difference to the production of carbon dioxide that we are individually responsible for.  All of these options will ultimately save you money as well as the planet!