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Energy efficiency, retrofitting, and sustainable construction supplementary planning document


Expand the sections below to read definitions and associated terms for each item.


Installation of energy efficiency measures in existing buildings.

Energy efficiency

Reduction in consumption of energy for heat and power.

Sustainable construction

Building with positive environmental impact.

Green infrastructure

Strategically planned network of green spaces and other environmental features.

Natural stack ventilation

Cool fresh air drawn in from openings at lower levels of a building by opening a ventilation out let at a higher level. For example, a window or ventilation hatch.

Biomass or biofuel

Plant derived fuel that is a renewable energy source.


Plastered sloped underside of a roof.


Materials and building fabric that allows moisture permeability.

SUDS (Sustainable Urban Drainage Systems)

Techniques to reduce adverse impacts of surface water drainage.

Cold bridge

Occurs when there is a thermal break in the insulating materials between the inside and outside of a building. For example, a gap in the wall or roof insulation allowing heat to escape.

Heating and hot water

Efficient controls

Installing a thermostat, thermostatic radiator valves and a timer will help to make heating systems work in the most efficient way and will reduce fuel bills.

Underfloor heating

In some cases, underfloor heating can be a suitable alternative to conventional radiators. The system uses a low operating temperature that can be linked in with alternative heating sources that output at the same low temperature, for example solar panels.

PV’s, solar thermal, biomass

By installing renewable energy systems to heat hot water and provide space heating, less fossil fuel is used and therefore less CO2 is emitted than conventional systems such as electric heating.

How people read


There are several choices of materials for window frames such as plastic, timber, and aluminium. Timber window frames are the best choice from an environmental point of view, but the timber should be sourced from well managed forests.

Glazing details

Heat loss through window glass is much greater than through walls and roofs. Insulating double or triple glazed units are now easy to source and the glazing unit is filled with an inert gas, making it even more energy efficient.

Solar shading

Adding blinds, shutters and/or solar shades on the outside of the windows can keep unwanted sun out in the summertime and will help to keep indoor temperatures at a comfortable level.

Thermal bridging

It is important to make sure that the gap between the window frame and the wall is well sealed otherwise heat will be lost around the window even if the window itself is very energy efficient.

Interior design


LED lighting (and to a lesser extent, compact fluorescent lights) use a fraction of the energy of normal light bulbs but give the same light output and there are a range of options to choose from. Although initially more expensive to buy, they last for many times longer than conventional bulbs and the costs are easily recouped over time. Natural daylight is even cheaper.


Synthetic paints contain hundreds of chemicals in them and can cause health problems when used. There are a number of alternative natural paints and finishes available that are better for the environment and better for the occupants.


There are many natural flooring alternatives to conventional synthetic choices (nylon carpet, pvc vinyl flooring and laminate as examples) that have a lower impact on the environment, are more durable and in many cases are healthier alternatives such as linoleum, wool carpet and solid timber flooring.



As much as 20% of energy bills can be saved by good loft insulation (200mm minimum) which is easy and inexpensive to install.

Room in a roof

Where appropriate, creating a room in the roof (the attic space) rather than building out to the side of back of a house can be less expensive and saves on materials. Even if the room is not in the original plans for the attic, making sure the roof is not filled with trussed rafters allows a room in the roof to be created at a future date.


Using natural slate or clay tiles as opposed to concrete tiles or asphalt means less energy is used to make the building materials in the first place thereby reducing fossil fuel use.

Solar panels

Providing the roof faces south (or south east/west) and is not in the shade, there will be an opportunity to generate heat for hot water and/or electricity from solar panels. The roof structure needs to be designed so that it is strong enough to take the extra weight of the panels.



Lots of heat is lost through unintentional gaps in the walls, floors and roofs of buildings creating draughts and so it is extremely important to make sure these are eliminated. This down to good detailing and good site workmanship.

Natural and mechanical ventilation

Fresh air is an important aspect of a healthy building and can be provided by natural ventilation systems rather than mechanical which use energy to operate.

Heat recovery

If mechanical ventilation systems are used, a heat recovery system can really help to capture and reuse the waste heat from outgoing air.

Indoor Air Quality (IAQ)

It is important to provide adequate fresh air into a building to maintain a healthy indoor environment and to remove pollutants such as smoke, cooking odours and off-gassing from building materials. When a building is very airtight it is even more important that fresh air is regularly introduced to a building through either natural or mechanical means.

Moisture control

moisture build-up in a building due to cooking, breathing, and washing can cause mould growth, resulting in an unhealthy indoor environment. Trickle vents in windows, mechanical extract, and careful use of opening windows can expel the moisture and keep levels down to a minimum.



Up to half the heat can be lost through uninsulated walls, so it is essential that adequate insulation in the cavity is installed. This can be in the cavity, internally applied, or externally applied depending on the construction of your wall. This will reduce fuel bills and make the building more comfortable to occupy.

Thermal mass

Using heavyweight materials such as brick, block and concrete can moderate the temperatures inside buildings by holding onto the heat during the day and releasing again at night time when it is needed.


Using natural materials such as brick and timber cladding means less energy is used to make the building materials in the first place, saving on fossil fuel use.


Reduce consumption

The best way to save water is to reduce it at the point of use so installing the following will help save water and reduce water bills:

  • low flush toilets
  • dual flush toilets
  • low flow shower heads
  • tap aerators.

Rainwater harvesting

Collecting rainwater and using it for washing machines, garden irrigation and to flush WC’s reduces the use of mains water (which is cleaned using fossil fuel energy) and reduces water bills.

Surface water runoff

if rainwater that falls onto a property is kept on site it can help to reduce the burden on mains drainage during heavy rainfall and allow topping up of the local water table. Using porous paving, swales, and retention ponds will all help to keep rainwater on site.



a significant amount of heat can be lost through uninsulated floors so it is essential that adequate insulation is installed. This can be below or above the slab, or between joists depending on the floor construction. This will reduce fuel bills, and make the building more comfortable to occupy.

Thermal mass

Using heavyweight materials such as concrete, or floor finishes such as tiles or stone, can moderate the temperatures inside buildings by holding onto the heat during the day and releasing again at night time when it is needed.


Using natural floor finishes such as stone, timber, and linoleum, means less energy is used to make the building materials in the first place and saves on fossil fuel use.