One of the most common things seen on older homes is the installation of new windows and this is how to tell the new windows weren't insulated properly when installed.
The Best Practice on new construction is to foam around windows and doors with a minimally-expansive, open-cell foam.
This provides a great energy seal impeding air flow, but also acts as very good insulation. It controls sound better too!
The windows and doors are more firmly held in place as well.
In the olden days they stuffed regular fiberglass insulation around windows and doors.
It was more haphazard, and probably not entirely effective, but at least there was insulation.
Inspecting this house I noticed something around what were advertised as "new" windows -
Staining in the form of air that is exiting the house.
If air is exiting the house air is also entering the house.
This is a process called infiltration and exfiltration. It is not a good condition. Air should not move so easily from out to in, and in to out.
This house has forced air heating and air conditioning. This pressurizes the house and can force air out of any gap. When the system turns off the air pressure equalizes again, drawing air back inside.
THE HOUSE IS BREATHING. IT IS IMPORTANT THAT HOUSES BREATH, BUT NOT AROUND WINDOWS AND DOORS!
What problems does such inefficiency around windows and doors lead to?
- Discomfort during the different seasons - rooms that are too hot and too cold
- The introduction of unwanted moisture
- Super energy inefficiencies when the HVAC is operating
- Pollutant and allergen movement into the house
These are not bad windows! They are vinyl, double-pane, and the sun cannot be felt through them - all desirable. What can we conclude about the installation of these new windows?
That they were slapped into place and likely have no insulation around them. In fact, there are probably large cavities all around.
THE INSTALLATION WAS NOT A PROFESSIONAL JOB.
There are two things necessary for new window installation to be an IMPROVEMENT:
1. That they are a good quality window and
2. That they are installed professionally - they are level and plumb, secured properly with shims and the right nails or screws, taped outside to seal them against moisture intrusion, and are insulated well, preferably with foam.
These two things are certainly a Best Practice.
My recommendation: when windows and doors have been replaced, see if you can determine who installed them - a neighbor or relative, or a professional company with professional and trained employees. If it's the former you may not have the "improvement" desired and the purchase is not what it is cracked up to be or hoped for. And look for clues that the installation was a good one!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560