3, January, 2018 By Gecko Posted in Part L Checklist of key design principles to help build more energy efficient homes The festive season now seems like a distant memory away and it’s business as usual for the construction industry. As well as being a key time for resolutions, January, by its very nature, is also one of the busiest times of the year for submitting planning applications. It’s when most of us working in the building industry reflect on what projects we have in store over the next twelve months and any necessary actions that need to be taken to ensure we get the green light to go ahead. With these projects in mind, the team at Base Energy have put together a list of key design principles to help you to build more energy efficient homes, to ensure swift and full compliance on your development projects. Orientation The orientation and layout of the property is the first place to start. How does its design and position help to utilise the sun’s energy to help heat the home, lessening the use of the heating system? The dwelling could also benefit from taking advantage of natural light sources and reduce its dependence on artificial lighting and heating. This is where solar gains come in to play. It needs to be designed it in a way which uses the sun’s energy but also prevents it from becoming too hot in the summer. Things to consider: Larger south facing windows combined with adequate shading. This will allow some light in the summer, but the shading will prevent overheating. Then in the winter, the lower angle of the sun will allow more solar radiation to reach the window and will heat the house up. Solar PV – Having a roof which is designed to be facing south, or as close to it as possible, and therefore maximise the efficiency of the solar panels. This will in turn, contribute in providing electricity to the home. Ecological shading This goes hand in hand with orientation. Just as it is important to maximise the sun’s energy in the winter months, you also have to ensure the house has sufficient access to shade in the summer. A great way to do this is by incorporating deciduous trees into the landscape design. These trees are extremely useful for natural shading as the leaves stop the sun entering the property during the summer and as they lose their leaves in winter, allow maximum light to enter during colder months. Size If you want to increase the size of the property, rather than expand across why not add an extra storey to the house? The more surface area in a house, the harder the heating/cooling system will have to work, so aim for a dwelling with less surface area. A dwelling with less concrete floor area means less transfer of cold air from the concrete floor. Also, the more cubic the design is, the more energy efficient it will be, as there is less thermal bridging which is where heat is lost through junctions in the building fabric. A simple design is more efficient than lots of unusual layouts and junctions. Building Envelope Once you have taken into account the orientation and position of the building, the next port of call is to look at what improvements you can make to its fabric efficiency. Enhancements could include: Increased insulation to the external walls, ground floor, roof and windows to stop heat escaping. This is the most cost-effective way to improve dwelling energy efficiency and helps to make it cooler in the summer and warmer in the winter, saving around 80 percent in heating and cooling losses. Lower the thermal mass. By installing an insulated panel system, timber frame or lightweight block, it will reduce the energy demand on the dwelling Make the longest side facing south to maximise solar gains. Air tightness: Make sure the house is air tight as this means there is less leakage and improves overall efficiency minimising heat loss. If the air tightness is 3m3/hm2(@50Pa), we suggest you install mechanical ventilation with heat recovery MVHR: You can improve air tightness by combining it with Mechanical Ventilation with Heat Recovery (MVHR). This is a ventilation system that both supplies and extracts air throughout a property. It offers a balanced low energy ventilation solution for new dwellings and re-uses up to 90 percent of the heat that would have otherwise have been lost. Waste Water Heat Recovery (WWHR): This is a low cost and efficient way to recover heat from shower waste water and can make a big difference to dwellings. Choice of boiler: There are a range of energy efficient boilers on the market and many of the main manufacturers also stock condensing boilers, which in some cases are supplemented by heat recovery systems. The above design principles are a great place to start if you are in the process of submitting a planning application or designing for building regulations compliance. Need some help? Base offers free design advice with energy assessments to help you maximise investment in your development, as well as working closely with your local authority to ensure swift building regulations compliance. For more information, or to speak to one of our energy assessors, call (0)20 3286 2016 or email firstname.lastname@example.org.