Energy efficiency is the new buzz phrase. Implementing it right can help you reduce the maintenance costs of your building, lower your environmental impact while also increasing your rental income.
From low-cost interventions to deep retrofits, this blog will give you 8 essential tips to increase your energy efficiency and help you reap the benefits in the shortest time possible.
Easy gains – behaviour changes
No investment is required – just a little information or education. Turn off lights when you leave a room and check that no exterior lights remain switched on longer than needed. Lower the temperature and duration of your washing cycle. Close doors to keep heat in each room, and close the windows when the heating is on. Open the windows to let fresh air in, but only when the heating is turned off.
Turn the boiler thermostat down to 43 degrees to save money instantly, and if you have a hot water tank, use the immersion only as a last resort and turn it off as soon as you have the hot water you need.
After boiling the kettle, put leftover hot water into a flask to save you boiling it again. But, it won’t get the full flavour out of your teabag, and here lies the key to successful and long-lasting behavioural change: If new habits lead to weak tea, tripping over in the dark, or the clothes not quite smelling right, it’ll all come to nothing. Habits need to suit inhabitants, so whether it’s your family or tenants, they need to be involved with and fully understand any agreements about how lights and appliances, doors and windows, should be used.
Of course, many aspects of behaviour are affected by routines and by the physical layout of the house. For example, if there is no light switch upstairs for the hall light, it is more likely to be left on, and if the clothesline is in an awkward location over a flower bed, the clothes are more likely to be put through an energy-intensive dryer cycle.
Implementation cost: zero or low
Financial savings: wide variance depending on the occupants, but potentially good
Environmental: wide variance depending on the occupants, but potentially good
How much do draughts cost you in heat loss and mould spray?
If you notice trickles of cold air or mould around doors and windows, they present an easy opportunity to reduce your heating bills and improve your thermal comfort. Seal them up using self-sticking draught tape, exclusion brushes, or a traditional draught snake, available online and in DIY stores. Chimney draughts can be resolved with a chimney balloon, and gaps in floorboards filled in easily with slivers, push-in strips or resin.
Now that we’ve minimised and sealed the gaps, won’t this lead to poor ventilation and mould? A draught is uncontrolled air movement and heat loss, both when you want it and when you don’t. If you want air movement open windows or trickle vents when the heating is off in the middle of the day, or use a purpose-made ventilation fan to clear stale air from the bathroom. When you want to heat the house, it will warm up quicker without draughts.
The house will be cheaper to heat, and the walls will maintain a slightly higher temperature, improving temperature stability and reducing the risk of condensation on walls. Draughts lead to cold spots, typically around doors and windows, where the incoming cold air cools the wall and condensation forms.
Implementation cost: low
Financial savings: medium to high
Environmental: Improved health and comfort, reduced condensation and mould
How much energy do your lights and appliances use?
You may think it’s hard to find anything other than low-energy light bulbs, but halogen bulbs are still common, rated at 40 watts. With the recent popularity of downlights we see that an old 100W kitchen bulb has been replaced with six downlighters, each rated at 40 watts, which is 240 watts. LEDs now come in many tones and are available for downlights typically rated at 4.5watts. The upshot is to use LEDs rather than halogen, and only the downlights necessary to light the space properly, for example, reducing 10 to 6, positioning them carefully to avoid the wall-mounted kitchen cabinets.
Appliances display their energy use in watts or kilowatts and an energy rating with a letter. The more energy-efficient appliances will cost more to buy, but they will reduce your bills also. Whether this will make you long-term savings depends on how you use the appliance and long it lasts too.
Implementation cost: low
Financial savings: medium
Environmental: medium
Insulate your house
Insulate to reduce your bills, increase comfort, and reduce condensation and mould.
Loft insulation is comparatively cheap and easy, with a quick financial return typically a couple of years. Flexible loft roll insulation made of recycled plastic is the easiest solution and creates minimal airborne fibres as you roll it out and cut it to fit your loft space. A natural solution is sheep wool, and a cheaper dustier version is Rockwool.
Wall insulation is more complicated, involving multiple trades and often scaffolding. It is more capital intensive and with a more extended return on investment, from 5-20 years. A simple financial cost vs bills savings calculation is unlikely to excite a homeowner or investor. Still, it becomes more compelling when considering savings associated with reduced maintenance, occupant comfort and health, and reduced carbon emissions.
Internal Wall Insulation(IWI) reduces internal space and requires replastering and decorating or an alternative wall finish. IWI targets rooms with acute condensation and mould. As a result, the room will be easier to heat, and the wall will feel warmer and less prone to condensation.
External Wall Insulation (EWI) forms a complete thermal envelope around the house and doesn’t impose on internal space. However, the walls will ‘grow outwards’ by about 130mm typically, and amendments will be required to drains, downpipes, and some eaves details.
IWI and EWI can be made of synthetic materials such as expanded polystyrene or natural materials such as cork and wood fibre insulation.
Floor insulation may be easily installed under bare floorboards, using a mesh nailed under floor joists to carry flexible insulation such as Rockwool, sheepswool, or plastic wool.
Implementation cost: medium to high
Financial savings: longer-term medium to high
Environmental: high
Breathable plasters and paints- moisture control, insulation, reduced heating requirement
Damp and condensation are widespread in Victorian terraces where walls are naturally cold and damp near the ground floor because of historic brick-built foundations with decaying or breached dampproof courses. There are broadly two schools of thought in the industry:
1) Use a chemical solution, squirting a chemical damp proof course into the bricks. The lower 1.2metres of plaster is replaced with a plaster mix which includes ethylene vinyl acetate to reduce salt movement, and staining, through the plaster.
2) Alternatively, install breathable lime or hemp plaster and breathable paint to allow moisture to move through and out of the brickwork. Wood fibre board or cork insulation are also breathable and can be installed with lime plaster as a breathable system to tackle damp in the walls long-term.
Implementation cost: high
Financial savings: longer-term medium to high
Environmental: very high
Maintain or replace your windows and doors
Windows are mostly double-glazed, though triple-glazed is the common target for low-energy projects. Doors are well insulated and are designed to fit snuggly with little movement over time to avoid draughts developing.
A common source of opportunity to reduce bills is to ensure that windows are properly maintained, meaning they can be easily operated to air the house and then to keep the heat in when closed.
Often lockable windows have small keys which get lost over time so that windows cease to be openable, or the heavy weight of the window leads to warping of the opening mechanism, the window becomes ill-fitting and draughty, or impossible to open.
Implementation cost: low (maintenance) or high (replacement)
Financial savings: longer-term medium to high
Environmental: medium to high
Low-cost heating and hot water using renewable energy sources
Boilers improve efficiency with new technology, so if yours is more than ten years old, you might make good energy savings by replacing it. Radiators can be flushed out, but over time they will become rusted inside and less efficient at emitting heat to the room. This means your boiler would be on for longer because the room thermostat doesn’t reach the desired temperature, and, of course, neither do you.
Modern double-fin radiators improve heat output, so the house heats up quicker, and the boiler can turn off until the thermostat demands heat again.
Underfloor heating can be an electric mat or pipes under your floor. Piped underfloor heating requires a hot water temperature of around 35 degrees, as the whole floor area is counted as a ‘heat emitter’. A radiator, in comparison, is a much smaller heat emitter and therefore needs to be hotter, typically 55 degrees, to heat the same space.
Underfloor heating lends itself to the use of an Air Source Heat Pump or Ground Source Heat Pump, which use ambient or ground temperature and cycling refrigerant to produce heat for domestic hot water and space heating.
Solar thermal modules can be installed on your roof to use the sun’s rays to heat your hot water via a hot water cylinder, which saves you money on fuel to heat the water. This is particularly well suited to sports clubs, hotels and restaurants where there is substantial demand for hot water during the day.
A photovoltaic system on the roof could also be used to heat hot water via an immersion heater in the hot water cylinder.
Implementation cost: low (maintenance) or high (replacement)
Financial savings: longer-term medium to high
Environmental: medium to high
How can solar panels save you money?
The primary logic of a photovoltaic (PV) installation is to reduce the electricity that you buy from an energy company. This is straightforward while the sun is shining, but a battery is required to use solar energy after dark. Batteries are becoming smaller, easier to install, and cheaper, but they generally reduce the short-term return on investment.
Get the most out of your PV installation by using your washing machine and dishwasher whilst the sun shines and the same applies if you have an electric car. Excess electricity automatically goes to the grid, though if you have a hot water cylinder, you can use an immersion device such as an Immersun or iBoost. These recognise when you are exporting electricity and turn the immersion on to use that electricity to charge your hot water tank, reducing your gas or other fuel consumption.
Implementation cost: high
Financial savings: longer-term medium to high
Environmental: high
Make your property eco-friendly and cheaper to maintain
The best way is to invest in the fabric of the house during construction or give an old problem house a full deep retrofit to set it up nicely for the future. But for most of us, it’s a matter of selecting the solution that fits our budget and our appetite for making changes, savings, and emissions reductions.
Fancy an expert view on how you can make your building more energy efficient? contact KGM Climate today for a free consultancy.
