Code for Sustainable Homes

The Code for Sustainable Homes

The Government has launched the Code for Sustainable Homes to integrate higher sustainability performance into the design of houses. The Code will reduce the overall environmental impact of the construction sector and will form the basis for future Building Regulations in relation to CO₂ emissions from, and energy use in homes.

The Code for Sustainable Homes has been introduced to drive a step-change in sustainable home building practice. It is a standard for key elements of design and construction which affect the sustainability of a new home.

It will become the single national standard for sustainable homes, used by home designers and builders as a guide to development, and by home buyers to assist in their choice of home.

It will form the basis for future developments of the Building Regulations in relation to carbon emissions from and energy use in homes, therefore offering greater regulatory certainty to developers. In this era of environmental awareness among consumers and increasing demand for a more sustainable product, it will offer a tool for developers to differentiate themselves.

Guidance moving towards legislation

The Code for Sustainable Homes is intended as a single national standard to guide industry in the design and construction of sustainable homes. It is a means of driving continuous improvement, greater innovation and exemplary achievement in sustainable home building.

The Code comprises an assessment and rating system aimed at improving the environmental impact of new homes by introducing minimum standards in nine key areas including energy/CO₂ and water. It sets different levels of energy efficiency for buildings so that when people buy a home they know how energy efficient it is and they will have some idea how much it will cost to run. In the short term compliance with the Code for Sustainable Homes is voluntary, but in view of the stringent standards required to achieve carbon neutrality for new built homes, it is expected that the Code will become mandatory in the near future.

Measuring sustainability

The Code for Sustainable Homes goes beyond the current Building Regulations in taking a “whole house” approach to house construction and its impact on the environment.

The key design categories incorporated within the code are:

Energy/CO₂ – Operational Energy and the resulting emissions of carbon dioxide to the atmosphere
Water – The consumption of potable water from the public supply systems or other ground water resources
Materials – The embodied environmental impacts of construction materials for key construction elements
Surface Water Runoff – The change in surface water runoff patterns as a result of the development
Waste – Waste generated as a result of the construction process and facilities encouraging recycling of domestic waste in the home
Pollution – Pollution resulting from the operation of the dwelling
Health and Wellbeing – The effect that the dwellings design and indoor environment has on its occupants
Management – Steps that have been taken to allow good management of environmental impacts in the construction and operation of the home
Ecology – The impact of the dwelling on local eco-system, biodiversity and land use

To achieve any of the Code’s ratings it will be necessary to meet the requirements covering a number of theses parameters.

Achieving a Sustainability Rating

The sustainability rating which a home achieves represents its overall performance across the nine Code design categories. Minimum standards exist for a number of categories – these must be achieved to gain a one star sustainability rating.

Energy efficiency and Water efficiency categories also have minimum standards that must be achieved at every level of the Code, recognising their importance to the sustainability of any home.

Apart from these minimum requirements the Code is completely flexible; developers can choose which and how many standards they implement to obtain ‘points’ under the Code in order to achieve a higher sustainability rating.

Table 14: Achieving a sustainability rating: minimum standards

Code level	Energy		Water		Other points awarded⁴
	Standard (% better than Part L, 2006)¹	Points awarded	Standard (litres per person, per day)	Points awarded
*1 ()**	10	1.2	120	1.5	33.3
2 ()**	18	3.5	120	1.5	43
3 ()*	25	5.8	105	4.5	46.7
4 ()	44	105	105	4.5	54.1
5 (*)	100²	80	80	7.5	60.1
6 (**)	A zero carbon home³	80	80	7.5	64.9

¹ Building Regulations: Approved Document L (2006) – ‘Conservation and Power.’

² Zero emissions in relation to Building Regulations issues (ie zero from heating, hot water, ventilation and lighting).

³ A completely zero carbon home (ie zero net emissions of carbon dioxide from all energy use in the home).

⁴ All points in this document are rounded to one decimal place.

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Our glass and rock mineral wool products contribute to the acquisition of points in the energy, waste, pollution, health/wellbeing and management sections of the code. In total, this could be as many as 28 of the maximum 104 credits on offer - which reflects the major importance of choosing the right insulation material.

Passive Design

Low energy, sustainable building techniques are already well established in other European countries. Passive Design aims to reduce a building’s fossil fuel energy consumption through better thermal performance of its components and systems - thus minimising heat losses in winter and heat gains in summer.

The first Passivhaus designs were built in Germany in the 1990s and since then, more than 8000 have been constructed across Europe. They are built to high standards of energy efficiency - equivalent to the demands of level 4 or 5 of the UK’s new Code for Sustainable Homes. They achieve this through techniques such as:

Making better use of heat from the sun through passive solar design
Extremely high levels of insulation and minimal thermal bridging
Excellent airtightness
Improved ventilation and heat recovery
Advanced window technology
The use of renewable energy sources for space and water heating
Low energy lighting and high efficiency electrical appliances.

The Code explained