Note: This depends on your location,weather types in your country and size of your house and room space that you will need in your home. Not all of us has attic or basement in our house and if there is no Winter Season in your location I doubt it if you need a boiler for water heater but there are water heater installed only used in shower.. There are already suggested cost /hour or day in wattage in appliances that you will purchase so you will have an idea how much it will cost you in monthly bill. Make plans and design for every space that you will build in your home that can cost of added expenses in renovation without compromising your security at home. Preparing plans / design for home of placing your windows can save you a lot switching on lighs during the day and also for proper ventilation. I am fortunate that my home is beside an electric post/streetlight so I do not need to turn on light overnight in front of our house or in garage because it lights up our entire house except light needed in room especially when my children uses laptop for work or school and gaming.