In 2005 when faced with the need to begin large-scale renovations at Plas Baladeulyn, the main house, we wanted to work with environmentally friendly materials where possible. The project included the replacement of the roof, rainwater goods and nine windows, plus a complete external redecoration. We also wanted to use local suppliers, though in practice this was not easy.

The roofing slates came from the Penrhyn Quarry, Llanberis ­ two valleys away. All roofing timbers were treated with boric salt impregnation for protection against fungi and insect attack. Boric salt is completely free of heavy metal salts and volatile synthetic agents and volatile organic solvents.

The roof insulation is Thermafleece, manufactured from sheep's wool from British hill sheep. Thermafleece requires only 14% of the embodied energy used in the manufacture of mineral fibre insulation. It proved easy to handle and had no loose particles to irritate the skin or breathing as often associated with mineral fibres.

Plas Baladeulyn after improvements

New windows were made from Welsh softwoods and treated with a borax impregnation primer, again completely free of organic solvents, heavy metal salts and volatile synthetic agents. The windows were fitted with 28 mm Pilkington K double glazing units, and special units made so the decorative Victorian painted glass windows could be retained.

All the exposed woodwork was painted with Aglaia natural paints. These are manufactured from natural raw materials and use no petro chemicals. They are also free of the offensive vapours associated with standard paints.

The existing wall rendering, of very variable quality, was treated with Beeck's Quartz Filler, a fibre re-inforced silicate primer to cover small cracks and to level out the surface structure. The aim was to avoid the large-scale removal and replacement of cracked render with all the cost and waste involved. The masonry was then painted with Beeck's Silicate Masonry paint - a natural paint, free of artificial resins and solvents. It is also non-flammable and no toxic gases are given off.

The rainwater system is of galvanised steel and produced by Lindab. This is much longer lasting than brittle plastics, is virtually maintenance free and manufactured according to ISO 14001 environmental management standards.

Note: Most standard paints and wood treatment products contain organic compounds and solvents that are potentially dangerous. Even when used according to instructions they give off vapours that adversely affect many people. Inorganic compounds do not suffer these problems and are safer to use and live with.

Our main supplier of paints, timber treatment and insulation was Calch Ty-Mawr Lime

Work in progress