Swn-Y-Nant, Oswestry - 19th and 26th October

Elegant Passive House built in 2019. Built in blockwork with timber frame, triple glazed windows and reconstituted roof slates.

The house is square. It has a raft foundation comprising 250mm dense polystyrene (Jablite EPS) with 250mm concrete (containing the underfloor heating pipes) on top. Blockwork walls with 250mm Permarock EPS insulation outside. Warm roof with 400mm Warmcell insulation. Our roof is made of an OSB box with dividers. The whole house is encased in a complete tea-cosy of insulation.  

The windows and doors are triple glazed and the whole house is very airtight (0.5 airchanges / hr), so we need a Mechanical Ventilation and Heat Recovery system which extracts moist air from kitchen and bathrooms passing it through a heat exchanger to heat fresh air brought into living and bedrooms.

We have a roof overhang on south side to reduce overheating which provides a lovely veranda.

A 9kW gas boiler runs the underfloor heating, two towel rails upstairs and the hot water occasionally. 4.8kWh array of solar PV which generates over 4,000kWh of electricity per year.

What have been the approximate energy savings?

It now takes only 1.5kW to heat the house. Our first year (2020) gas bill was only £96. It has since gone up a bit more. We got onto the SEG tariff for the electricity, exporting to the grid late in 2020 resulting in us receiving over £400 in 2022.

What have been the benefits to you and your home?

It is very comfortable to live in, the temperature does not change much due to the thermal mass of the floor slab and all the insulation. The home is also very quiet as triple glazing lets virtually no sound through. It has been very economical. Our Energy Performance Certificate (EPC) is rated A.

For more information please see attached PDF.

Additional information

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