It is a common misconception that building an Eco home is an expensive business, especially when taking into consideration the standards set by the Code for Sustainable Homes (CSH). However, eco houses needn’t be expensive to build, and will often cost a lot less to heat in the long run than other homes, meaning that the long-term costs are also pretty low. A recent study carried out by English Partnerships showed that, on average, the cost of reaching the targets set by the Code for Sustainable Homes Level 3 will be 12-15% greater than those incurred in meeting the current Building Regulations standards. The research assumed an average 120 square metre three bedroom UK home, but is not specific about where the money is spent.
How the Code for Sustainable Homes works
The Code for Sustainable Homes is used to assess the drawings and specifications of the planned dwelling and to award the plans points out of a total 100. To reach Level 1, you must achieve 36 points; Level two requires 48 points; Level 3 requires 57 points; Level 4 – 68 points; Level 5 – 84 points; Level 6 – 90 points.
The points are awarded in nine categories of design. These categories are:
1: Energy and CO2 emissions
4: Surface Water Run-off
7: Health and Well-being
The nine categories are separated into two main groups. These groups are entitled ‘Mandatory’ and ‘Other’. The mandatory categories are Energy and Water, and the remaining elements each make up the ‘other’ section. Within ‘Other’ is a subgroup consisting of Surface Water Run-off, Waste, and Materials, within which a number of minimum standards still has to be reached.
How to work the Code for Sustainable Homes
Design is the key element when preparing for the CSH assessment. This is because the assessment is carried out at the design stage of the project, before any of the construction work has even begun.
It is also worth noting that the Mandatory section is only actually worth up to 10.3 points of the final score, whilst the remaining 46.7 points are made up from the Other group. Within the Other group is a number of fairly easily achievable targets which can add a few helpful points to the score. For example:
- A Home User Guide, which is essentially only a folder containing the manuals for every appliance and piece of equipment in the house (such as dishwashers, washing machines, and central heating equipment) is worth a possible 3.3 points.
- A clothes drying space, which needs to be no more than a simple set of fixtures for erecting a washing line (not including the line itself) is worth an additional 1.2 points.
- A secure bicycle store is required for any four bedroom home, with room for at least four bikes. The store can be a lockable shed or a simple couple of bike racks which can accommodate the four bikes. This is worth another 2.4 points.
- A home Office is simply the ‘provision of space that can be set up as a home office’. The room must include a telephone point and a double power socket as well as enough space for one person to work. When the house is lived in, the room can be used for any purpose you like, but setting it up as usable as a home office can be worth another 1.2 points.
- White goods, if each is specified as A+ rated in the planning drawings, can be worth another 2.4 points.
You will find that you can easily achieve half of the necessary 46.7 points with very little trouble, simply by seeing to the little, low-cost alterations in the design as demonstrated above, and labelling them on the design drawings so as to properly bring them to the attention of the Code for Sustainable Homes assessor.
The Mandatory elements of the Code for Sustainable Homes
The water consumption (both internal and external) must be limited to 105 litres per person per day. This is calculated by quite a complex system, but it is easily put into perspective as the average UK home uses 150 litres of water per person per day, meaning the reduction is of around 30% per person per day.
This is fairly easily achievable, and there are two simple ways of going about achieving this kind of water usage. One way is to utilise a greywater recycling system (costing around £2,000) which should achieve the target by itself. Another way is to consider using aerated taps and/or reduced-flow shower systems.
The energy requirement is that a 25% improvement on Building Regulations 2008 Part L is achieved. This is pretty simply done, and there are a few ways of doing it. Construction systems such as SIPs, for example, which are highly insulated and relatively airtight, with solar thermal systems fitted on the roof, can achieve the 25% improvement alone. Other construction systems such as brick and block, for example, will require greater thought when it comes to the heating and hot water systems. A SEDBUK A-rated boiler or heat pump is essential, but you will still need to upgrade the insulation levels. It is in this area that most of the extra cost will become apparent.
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