Performance house roof

Performance house: Roof

Maximisation of natural light

The amount of natural light entering the property has been increased so as to reduce the need for artificial lighting and the energy to produce it within the property. It is also believed that the extra natural light will be conducive to the wellbeing of the residents. A Velux Window has been installed above the stairs with a light well from which natural light cascades down through the first floor landing to the ground floor hallway.

Roof insulation

Loft spaces have been insulated with 325mm Black Mountain Natural Hemp (195KB) insulation achieving a u-value of 0.12 W/m²K. The product is manufactured from a blend of hemp and other natural fibre, incorporating a binder to ensure that the product retains its thickness. 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.

Green roof

green roof by Langley (3,761 KB) has been installed to the new rear extension. The green roof retains 70-90% of precipitation, thus reducing surface water run-off, which helps to reduce the risk of flooding by relieving the drainage systems. The roof will provide a rich habitat for a variety of flora and fauna species. It also has a high thermal performance.


Solar thermal panel

A solar thermal panel has been installed; this will assist in heating water. Solar thermal energy can produce up to 60-70% of a domestic property’s annual output. All hot water outlets are provided with hot water from a twin-coil pressurised unvented hot water cylinder, located in a storage cupboard on the first floor landing. The lower coil is served by a 3 m² bank of Viessmann Vitosol 200T (328KB) SD2A evacuated borosilicate glass tube solar thermal collectors mounted on the west facing pitched roof. Collected solar energy is used to pre-heat the cold water supply, thus reducing the load on the boiler plant, and therefore saving gas. The upper coil is served by the gas-fired boiler. The expected output from the solar thermal panel is 933 kWh per annum.