22 THE CLIMATE CHALLENGE
changes for housebuilders, as ultimately we need our homes to be zero carbon ready to meet future legislation.
TAKING A FABRIC FIRST APPROACH What will this mean for new homes and how will architects meet these rigorous standards? One key area will be addressing the thermal performance of a building envelope through a fabric first approach to building design. If we get the fabric right and we build as designed, we will go a long way to meeting our targets. It’s an approach that will enable us to meet and even exceed regulatory performance criteria, whether it is for large scale private or social housing or a much smaller residential property. While a reduction in CO2
emissions
is one consideration when designing thermally-efficient housing, an improvement in thermal comfort can also have a positive impact on occupants – adding to their wellbeing, but also aspects like productivity for work.
STOP THERMAL BRIDGING A critical element of the fabric first approach will be addressing the issue of thermal bridging, which can be responsible for up to 30% of a home’s heat loss. Eliminating thermal bridging through good design and correct product specification will be essential if we are to ensure we meet these ambitious new regulations. While there are some design, measurement and calculation issues, the other concern in terms of thermal bridging is that we are neither building consistently
WWW.HBDONLINE.CO.UK
what we design, nor detailing the right products in the right places. There are also issues with site skills and workmanship; when you fail to build correctly it undermines the good work carried out in the first instance. This can lead to a ‘performance gap’ between as-designed and as-built building performance. It’s why these weak spots can significantly impact a building’s heat loss and have a detrimental effect on the overall fabric efficiency of the external wall.
AN OFT-OVERLOOKED BRIDGE Often overlooked when it comes to thermal efficiency due to a focus on insulation, window and doors, is that traditional steel lintels can create a significant thermal bridge in homes. This is due to the high thermal conductivity of steel, and because they span over
THE OTHER CONCERN IN TERMS OF THERMAL BRIDGING IS THAT WE ARE NEITHER BUILDING CONSISTENTLY WHAT WE DESIGN, NOR DETAILING THE RIGHT PRODUCTS IN THE RIGHT PLACES
long lengths in a typical build. However, solutions have developed to address this. For instance, a steel lintel that incorporates a thermal break can be up to five times more thermally efficient than standard alternatives, and such a solution has been specified on many housebuilder projects around the UK. When you consider the BRE has found that thermal bridging can account for up to 30% of heat loss from buildings, then paying close attention to the details and structural elements such as lintels can have a huge impact on the overall thermal performance of a building. At a time of spiralling energy costs and the current energy crisis showing no signs of abating, making homes more energy efficient through a fabric first approach will go some way to locking in savings for the lifetime of a building and achieving our climate change targets.
NET ZERO HOUSING We have produced a webinar that’s useful for anyone seeking to learn about the delivery of net zero housing, titled ‘How are we going to deliver Net Zero Housing’ It is one of four in a series of free webinars featuring expert industry speakers discussing the challenging topics and issues the industry is currently facing. With changes on the horizon for the design of our new build houses, it will be incredibly important for housebuilders to specify materials and components which deliver the difference between a sustainable and an inefficient home.
Ciaran McAliskey is national specification manager (Ireland) at Keystone Lintels
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
