Comfort is a big factor, especially in an old home. So when you are doing renovations, such as the basement recreation room, it's worth the small additional investment to add extra insulation in the walls. Insulation will improve comfort, energy efficiency rating of your home, and save on energy costs.
Keeping humidity level at 35% is good lower value for a house. Low humidity level is important because mould, dust mites and another allergens thrive in humidity. Dehumidifier during the winter and an air conditioner during the summer months can help.
The most common indoor allergen is dust mites. The best ways to limit them are: keep low humidity in the house, use impermeable covers for mattresses and pillows, launder your bed linens weekly in hot water and hot dryer. Bedding that can't be washed in hot water, such as blankets or comforters, and stuffed animals, can be placed in a bag and put in the freezer for 24 hours to kill the mites. Using air purifier with HEPA filters to filter the air is very good idea. Also regular cleaning (vacuum, dust, mop) can help to reduce them. Limiting the objects in the house they collect on is good idea too. The other common allergens are animal dander and mould spores. The same maintenance suggestions given above will also limit them.
The best way to clean glass doors on fireplace is with a product especially made for this job. You can find it at your fireplace dealer or your local hardware store. Make sure the fire is out and the glass is cool before you start. For stubborn spots use a nonabrasive pad.
Choose varying shades of the same light color to make small space feel larger. If you paint the walls, doors and trims with the same color your space will look larger.
Each heating season should start with a clean filter. You should replace or clean your filter every month after that. A clogged filter makes blower work harder and reduces the system's efficiency.
Most garages have a single light hanging from the ceiling which is definitely not emitting enough light to do any work. Luckily, lighting up your garage can be simple and inexpensive with a fluorescent light fixture. They are available in a variety of lengths and can be easy installed. You can just plug them into a power source -- no need for electric wiring. If you want them on your ceiling, these fixtures can easily be installed by hanging from chains mounted into ceiling and plugged in into existing power source.
Odors from your humidifier indicate the presence of bacteria in the water reservoir or filtering system. The best way to kill bacteria is to clean the unit with the antibacterial cleaner recommended by the manufacturer. If you don't have it, you can kill bacteria in the humidifier with a solution of 1 tablespoon chlorine bleach per pint of water. After cleaning, rinse thoroughly with plain water.
Keeping an eye on the value of your home as you improve it will make a big difference when it's time to sell.