Sustainability and Modern Methods of Construction
Reasons why Sustainability and modern methods of construction should matter to you
Waste to Landfill during Construction
Research carried out by WRAP has also stated that off-site construction generates up to 80 per cent less waste compared to site-based building methods, clearly a vital ingredient in green construction. This is as a result of the factory environment, giving greater control of materials and affording greater opportunity to Reduce, Re-use or Recycle waste, although figures in the report indicate volume of waste to landfill could still be as high as 19.16m³ per 100m² of floor space (Timber frame). A sustainable choice should mean minimal waste to landfill, so it is important to ensure your supplier has a good solution to this. There are some instances of poorly installed components resulting in increased landfill as a result of waste materials.
When choosing a Modern Method with a desire for Green Construction, key pointers are ensuring professional installation and checking that Site Waste Management Plans are in accordance with WRAP guidelines. This is a regulation requirement for all projects over £300k – but should be sought where-ever sustainability of the project is wanted.
Most recent figures for Cabinco on a site where a full SWMP could be put in place we achieved figures as low as 0.3 tonnes to landfil for each 100m2 of new build area.
Energy performance for MMC Buildings
Again, when a product is precision machined with factory tolerances, then performance, including “U” values and air tightness, should be dramatically improved compared to traditional construction methods. It is difficult to accurately compare to traditional construction as there are so many variables, but figures of 0.42W/m²K are advertised by some insulation companies for a brick block insulated wall. Volumetric types of Modern Construction Methods, off site manufactured units delivered “ready made”, performed least well with U values of 0.32W/m²K published for the walls (Brand name volumetric supplier). These manufacturers could offer improved performance but keep insulation levels low, though within regulations. Solid timber buildings (MPL) with cavity insulated walls performed at 0.14W/m²K (Cabinco) with 150mm of insulation.
Further checks on energy efficiency include the air pressure test. Normally the lowest acceptable standard for commercial properties is 10m3/hr at 50Pa, however, MPL with Cabinco will generally achieve around 3-4 m3/hr at 50Pa with lower achievable if required. If you look at our Zero Carbon Buildings, you will see that below 3 m3/hr at 50Pa and with the addition of a solar array – MPL by Cabinco will acheive zero carbon or carbon positive status.
It is worth considering whether your objective in seeking sustainability is to simply improve on past poorly performing buildings, or to obtain the best energy efficiency for the future. Green construction should provide you with the lowest U values to ensure minimal wasted energy and, correspondingly, you should see a return on your investment in the form of lower energy bills and the knowledge that you are helping the planet.
Sustainability of Materials
Many companies employing Modern Methods of Construction will offer options for greener buildings. Some will rely on sustainable energy systems or sedum roofing – largely volumetric MMC. Others will offer this plus a greater range of sustainable materials in the fabric of the building itself. This includes Timber Frame which can offer sustainably sourced timber cladding as an external option but normally rely on plaster board internally. Companies such as Cabinco offer a fully recyclable building envelope through their system of Machine Profile Logs (MPL) where both the internal wall and external wall are sustainably sourced timber.
Sustainability at the end of the life cycle (Design for Deconstruction)
What happens to the building at the end of its useful life? How much of its structure can be recycled (steel, glass, timber) and how much of it will go to landfill (panels, plaster, insulation).
For clients to make the most of the benefits of Modern Methods of Construction, and to achieve truly Green Construction, they need to select a system which combines off-site manufacture, sustainable materials, low U values and efficient/independent energy use. The product which is able to offer best overall performance on all these items is MPL (Machine Profile Log)