Insulation is key to energy efficiency. You can add insulation in the attic, walls, and crawl spaces. Fiberglass insulation is common, but spray foam insulation provides better air sealing. It fills gaps and cracks, preventing air leakage. However, spray foam is more expensive. Proper insulation keeps the house warm in winter and cool in summer. You should also check for air leaks around doors and windows. Weatherstripping and caulking can help seal these gaps. But, make sure to use the right materials for different areas. For example, exterior caulking needs to withstand the elements.

Heating and cooling systems are essential for comfort and energy use. Upgrading to a high-efficiency furnace or air conditioner can save energy. A heat pump is a versatile option, as it can both heat and cool the house. But, it requires proper installation and maintenance. You can also consider zoning your home's heating and cooling, which allows you to control temperatures in different areas. Smart thermostats can help you optimize energy use by adjusting the temperature based on your schedule. However, they need to be programmed correctly. Additionally, consider the ductwork. Leaky ducts can waste a lot of energy, so sealing or replacing them can improve efficiency.

Appliances also contribute to energy efficiency. Look for ENERGY STAR-rated appliances, like refrigerators, washers, and dryers. They use less energy without sacrificing performance. You can also consider energy-efficient lighting. LED bulbs are a great choice, as they last longer and use less electricity. Solar panels are another option. They can generate electricity and reduce your reliance on the grid. But, they require a significant investment and proper orientation for optimal performance. You might also consider energy-efficient windows, as mentioned earlier, and proper shading to reduce solar heat gain in summer.

Improving energy efficiency during house renovation is a win-win situation. It helps you save money and reduces your environmental impact by making your home more sustainable.