Sustainability
We are committed to reducing the environmental impact of living and building low energy homes with genuine sustainable credentials. We continuously look for pioneering ways to make our homes the most efficient they can be, positioning them at the forefront of modern living.
Our homes currently achieve an outstanding Band A efficiency rating. We use leading green technologies — such as mechanical ventilation heat recovery, air filtration, photovoltaic panels and air source heat pumps — combined with A rated appliances, triple glazing and LED lighting throughout the home.
To encourage wildlife to thrive, we plant new trees and shrubs in our gardens then fit bird and bat boxes to attract and sustain a diverse range of species.
How we build
low energy homes
A low energy home must be well-insulated, airtight, energy efficient and capable of producing as much renewable energy as it consumes over the course of a year — leaving homeowners with a net zero energy bill.
We use the highest level of insulation, seal all the joints and triple glaze the windows. A continuous heat recovery ventilation system (MVHR) keeps the interior air fresh, as well as dust and pollen free. We also use this system to recover 95% of the heat within the house to preheat external air coming in. Whilst the energy demand to heat the building is very low, any additional energy needed for hot water, heating and cooking is topped up by an air source heat pump. The energy needed to run the ventilation system and heat pump is generated using photovoltaic panels, which convert light into renewable energy. A rated appliances and LED lighting help to improve energy efficiency. This combination of energy saving measures and renewable energy generation gives homeowners an efficient, economical and highly comfortable home.
The technology in detail
SIPS Building System
Structural insulated panels (SIPs) are a high performance building system. The panels consist of two pieces of oriented strand board (OSB) with 112mm of rigid insulation sandwiched in-between. SIPs are manufactured under factory controlled conditions and can be fabricated to fit nearly any building design, forming the whole internal part of a new build property. There are no un-insulated gaps in any of the external walls or roof area, resulting in a highly energy efficient home with very low running costs and fast heating response periods.
The SIPs panel achieves a U-value of 0.19W/m2.K for walls and roof construction. You would need much thicker walls and insulation to achieve this figure using traditional building methods. The highly efficient structure benefits from virtually air tight construction, as low as 0.08 air changes per hour under normal pressures.
MVHR
Whilst airtight construction is essential to help reduce heat loss and carbon emissions, the internal environment can become stale without a continuous flow of fresh air. This can lead to condensation, mould and the possibility of health related problems such as asthma. A heat recovery and ventilation system will change up to half a room’s air every hour, bringing fresh filtered air into the room that’s free from airborne dust and pollen.
The system works by sucking the warm moist air from the kitchens and bathrooms into a heat exchanger, which extracts 98% of the heat from this stale air. It then transfers the heat into the fresh incoming air, which flows into the living areas and bedrooms.
Triple Glazing
A triple glazed window contains three panes of glass separated by a pocket of argon gas, adding an extra layer of insulation over double glazing. This extra layer makes it more difficult for heat to escape, making it easier to maintain the temperature in your home. The air gaps in triple glazing are too small to allow the air to circulate and therefore prevent heat transfer by convection. Because the argon gas is a poor conductor, it reduces the rate of heat loss through the window.
Triple glazing provides a warmer home in the winter months and reduces energy bills by preventing heat loss. This means you don’t have to heat your home as often.
Air Source Heat Pump
An air source heat pump system consists of an external box which fits onto any outside wall. It harvests renewable low grade energy from the fresh outdoor air and converts it into useful energy to supply the home with hot water and heating. Typically, every 1kw fed into the pump creates at least 3.8kw of energy in return (380% efficient). A heat pump works effectively down to a temperature of -15° C — perfect for the UK climate.
An air source heat pump works on the reverse principle of a refrigerator, which is effectively a vapour compression cycle. The four main components inside the external box are the evaporator, expansion valve and two heat exchangers (one evaporator, one condenser).
Photovoltaic Panels
PV panels consist of small photovoltaic cells that are connected together. These cells are made out of semiconducting material, with silicone being the most common. When the sun shines over the cells, an electric field is created. The stronger the sun, the more electric energy is produced. However, the cells don’t need direct sunlight to work, so can still produce electricity on a cloudy day. The strength of the cells is measured in Kilowatt peak (KWP), which is the amount of energy the cell produces in full sunlight. Solar energy from a PV panel is a truly renewable and green energy source, which doesn’t release any carbon dioxide or other pollutants into our air.
A typical home could save around 1200kg of CO2 per year, equating to 30 tonnes over the course of the panel’s lifetime. PV panels also greatly reduce household electricity bills. The systems we use can generate up to 40% of the energy needed in one year. There’s also the potential to receive payments for the surplus energy that you export back to the grid if you generate more electricity than you use.