Performance house ground floor

Performance house: Ground floor

Floor insulation

To the suspended timber ground floor to 47 Addington Road 325mm Black Mountain Natural Hemp (195KB) insulation has been installed between the floor joists. The insulation here is hung on nets to support it and hold it into position. Hemp is said to have excellent insulation properties due to its low thermal conductivity and high thermal mass. It is a breathable material that is able to absorb, retain and release moisture whilst retaining its thermal properties. The product is treated with a simple compound to achieve Euroclass E fire performance.

Condensing boiler

A new high efficiency, Viessmann, Vitodens 200-W 19kW condensing boiler (675KB) was installed. The boiler is SEDBUK ‘A’ rated and operates at an efficiency of 90.7%. Condensing boilers work on the principle of recovering waste heat which is normally rejected into the atmosphere from the flue of a conventional boiler, and using the recovered heat energy to pre-heat return water. The boiler has weather compensation controls. This means that changes in outside temperature are detected by an outdoor sensor, so when the temperature drops, the boiler operates at a higher temperature to maintain room temperature. This differs from conventional controls, where the need for the boiler to operate at a higher temperature is not detected by the room thermostat until the rooms become colder, during which time the householder is likely to feel cold and to turn up the thermostat, thus wasting fuel. With conventional controls, if the outdoor temperature rises, the boiler will not respond until the rooms have become uncomfortably warm. If the householder responds to this by opening windows, heat energy is being wasted.

Underfloor heating

An underfloor heating system (2,213 KB) has been installed, which is considered a more efficient than wall mounted radiators. Underfloor heating (UFH) is provided to all rooms by a system of plastic pipes below the floor boarding, containing heating water. Most rooms have timber suspended floors, for which a ‘plated’ system is employed. Metal heat dispersion plates span the floor joists. These plates have grooves in which the UFH pipes are fitted. Floorboards and floor finishes are fitted on top. The metal heat dispersion plates are installed just above the hemp insulation that is installed between the floor joists. The rear addition has a solid floor, so 25mm thick slabs of phenolic foam with grooves for the UFH pipes are used here. Floorboards and floor finishes are again fitted above this layer.

Each room is set up as a separate thermostatically controlled zone. All ground floor rooms are piped from a manifold set located in the under-stairs cupboard. First floor rooms are piped from a manifold set located in the first floor cylinder cupboard. Wall mounted thermostatic controllers operate motorised ON/OFF valves on the manifolds, so that when a set-point for a room is reached the valve shuts.

The zoned control system maximises the efficiency of the system by enabling the occupants to adjust the temperature within each room and thus deliver heat only to areas where it is required. Underfloor heating also offers superior comfort levels to conventional heating methods. The diagram below shows three temperature profiles. Temperature Profile 1 is a theoretical natural temperature profile, 2 is the temperature profile provided by under floor heating and 3 is the profile provided by a conventional radiator system.


Log burner

The existing gas fire was replaced with a Stockton 4 Log Burning Stove (3,481 KB) by Stovax. The front chimney which had previously been reduced had to be re-built to accommodate the flue. The log burner is 77% efficient when burning wood and 85% efficient when burning smokeless fuel. The replacement of the gas fire with the log burner will save approximately 250 kg of carbon dioxide per year. Timber was set aside as the strip out work took place and this will be used as fuel for the log burner. Link above to Stovax Wood & Multi Fuel Stoves PDF


Voltage optimiser

A VPhase voltage optimiser (2,207 KB) has been installed to the incoming mains electricity supply to both properties; this takes the current and optimises it to make it more efficient for the appliances and fittings within the properties. The UK electricity distribution network operates at a nominal 230V, although in practice average voltages are more likely to range between 240V and 245V. The VPhase unit manages voltage to a stable level, normally 220V in the UK, regardless of the incoming supply voltage. The amount of energy saved is device specific, for example: testing by VPhase on fridges and freezers shows 17%, 15% on normal lamps and 10% on energy saving lamps. One digital cordless phone showed an extraordinary saving of 44%. Savings will vary depending on incoming voltage and individual devices.

Marmoleum floor covering

Marmoleum (7,129 KB) floor coverings have been laid in the kitchen, bathrooms and utility room. Marmoleum linoleum product that is made from natural, renewable resources and is therefore biodegradable.


Chamois Kitchens

The Chamois (2,050 KB) kitchen units installed were manufactured from recycled materials including recycled glass. JTimber All new timber is Forest Stewardship Council (FSC) certified. The FSC global forest certification system enables consumers to purchase wood and timber products in the knowledge that they have been sourced from well managed forests and that their products are not contributing to deforestation.

Low VOC emulsion and gloss

Ceilings, walls and internal joinery have been painted with emulsion and gloss that has lower amounts of Volatile organic compounds (VOCs). VOCs are emitted gases from solids or liquids, some of which can have adverse health effects. The emulsion and gloss is from the Dulux Ecosense range.