Buildings & the environment

not harmful to the environment - Installing solar panels to cut down on the use of fossil fuels is one of the best ways to make your home _____.

material used to stop heat escaping - In cold climates, it’s important for buildings to be well _______ and glass fibre is often used as roof _____.

using little electricity, gas, etc. - These days, one of the most important considerations in building design and the choice of building materials is _______cy.