About Your House
Window and Door Renovations
Windows and exterior doors are subject to the wear and tear
that comes from constant use and exposure to the weather. Over
time, weatherstripping, hardware and the door and frame
materials can deteriorate or fail. Homeowners can either
repair or replace window or door units. Repairs can be
inexpensive, but may not give good long-term results.
Replacement is generally costly, but will provide cost savings
in energy use, make your house more comfortable and add to the
There are a number of factors to consider before making the
decision about whether your windows or doors need to be
replaced or whether they can simply be repaired.
Some important areas that you will want to consider
- Style and design — your existing
windows and doors may not fit the style of your house or
give you the features that you want. There may not be enough
glass area to provide adequate natural lighting to the
- Components and hardware — the
components of windows and doors wear out over time. Failed
seals on thermal pane window units, poorly operating windows
or doors, damaged screens or hardware and air leaks are
common problems. Older door and window hardware may not
offer much protection against forced entry.
- Structural problems — there may be
structural problems that are affecting the operation of
doors and windows. Installation of larger units or units in
new locations will probably also require structural changes.
- Moisture — windows and doors often
deteriorate due to moisture problems, which will not
necessarily go away if you install new units. In fact,
moisture may even get worse, due to reduced air leakage.
- Heating and ventilation — the glass
area of windows and doors accounts for a high degree of heat
loss at night or heat gain when the sun is shining. Energy
efficient glazing can reduce heat loss. Heating system
modifications or some type of shading may be needed to
improve comfort near large window areas.
Renovating is an ideal time to make your house healthier
for you, the community and the environment. When assessing
your renovation project, be sure to consider the five
essentials of Healthy
House as a System
A house is much more than just four walls and a roof — it’s
an interactive system made up of many components including the
basic structure, heating, ventilation and air conditioning
(HVAC) equipment, the external environment and the occupants.
Each component influences the performance of the entire
system. A renovation provides an opportunity to improve how
your house performs.
Tighter and more energy efficient windows and doors will
reduce the heating load on your house, reduce heating costs
and improve occupant comfort. Energy efficient glazing can
also reduce condensation problems that damage finishes and
lead to mold growth. Increased house airtightness can improve
energy efficiency, but may also lead to a greater need for
mechanical ventilation. A sufficient air supply may also be
needed to prevent combustion appliances from backdrafting.
There are many choices available to homeowners who want to
upgrade or make changes to the windows or doors in their
homes. Taking the time to examine your needs and the options
that are available is the right way to start to plan for your
renovation or repair job. Here are some of the likely
situations that people encounter.
|Style and design|
- Do the important living areas of your house
receive adequate natural lighting?
- Do you have or want windows or doors that connect
you with outdoor living areas, interesting landscape
features or views?
- Do the windows and doors match the original style
of your house?
- Do the windows and doors have the appearance,
durability and maintenance requirements that you
- Increase the glass area. For good natural
lighting, glass area needs to be about 10 per cent of
the floor space.
- Add windows or doors to connect you with the
outside environment. Make sure the weatherstripping
prevents or minimizes air and water leakage.
- Choose replacement windows and doors that fit with
the original style of the house.
- Select windows and doors that meet your needs. If
you are replacing all of the windows and doors, you
may want to totally change the look and feel of the
house by choosing units of a completely different
- Consider the use of a professional designer to
help explore your options.
- Poor natural lighting can detract from your
enjoyment of the renovation. If you compromise on your
choices you will have to live with the results.
- Adding another door or window later will be more
costly and may not fit well with other renovation work
that you have done.
- Poor selection can result in windows that look
bad, perform poorly or require excessive maintenance.
A designer can help to avoid problems such as
installing too large a glass area on the sunny sides
of the house that can lead to overheating unless sun
controls (e.g., large overhangs, awnings or trees) are
- Are your windows and doors in good operating
condition and free from wind or water leakage?
- Are glass surfaces easy to reach for cleaning?
- Are storm windows and screens easy to install and
in good condition?
- Are the latches, doorknobs or weatherstripping in
- Do your doors have security features such as door
viewers, deadbolt locks, reinforced striker plates and
- Is your window hardware adequate to resist forced
- Does each bedroom have a window that allows egress
in case of fire?
- Replace or repair worn out window or door units.
- Choose new window units that open or tilt in for
easy cleaning. Familiarize yourself with available
products and options. Pay attention to energy
- Replace worn or damaged latches, doorknobs or
- Install deadbolts on exterior doors. Use door
viewers or glazing to give you a clear look at your
caller. Install longer screws at hinges or striker
plates. Install solid blocking between the jamb and
framing at hinge locations and striker plates.
- Install bedroom windows that have openings that
meet the National Building Code requirement for
- Window and door units will continue to be a source
- You may put yourself and your family at risk.
- Are there existing structural problems that affect
your windows and doors?
- Will installation of new windows or doors require
special structural details or changes in electrical
and plumbing services?
- Carry out an inspection to help you understand the
cause of any existing structural problems. Look for
cracked or binding windows and doors.
- Repair or strengthen structural components so that
they are adequate to carry the loads over existing or
- Consult with an expert to help you with the
structural part of the work. Use a licensed
tradesperson to disconnect or move any electrical or
- Structural deficiencies can lead to difficulties
in operating windows and doors.
- Other structural problems can show up as cracked
finishes or glass, bowing or displacement of walls and
roof structures and possible structural failure.
- Structural, electrical or plumbing modifications
that are not up to code can be a safety hazard.
- Is there moisture damage to any of the windows and
- Is there moisture between the two panes of glass?
- Is there visible mold growth on any surfaces? Are
there water stains?
- Has there been condensation on glazing, jambs or
- Is there blistering or peeling paint?
- Is any of the caulking cracked or missing?
- Are the flashings in good repair?
- Determine the source of the moisture. It may be
from building leaks or condensation of vapour on cold
- Replace the sealed unit.
- Modify or move curtains, plants or window screens
that are keeping warm air from getting to the window
- Clean up visible mold growth according to CMHC
- Insulate, air-seal or use energy efficient glazing
to provide warmer inside surface temperatures.
- Provide ventilation and eliminate sources of
moisture to control high humidity.
- Replace or repair all deteriorated finishes or
- Maintain caulking and flashings to prevent water
access to the building structure.
- Unsolved water damage problems will continue and
lead to further deterioration of the building or newly
- A broken seal will allow moisture to build up
between the panes, reducing the window efficiency and
possibly causing breakage.
- Mold growth caused by excess moisture can be a
serious source of IAQ problems.
- Superficial cleanup or hiding moisture damage
behind new finishes will allow deterioration to
- Do large areas of glass make the room
uncomfortable and hard to heat?
- Does excess condensation form on windows or other
- Do large areas of glass lead to overheating from
the sun’s energy?
- Make sure that there is adequate heating supplied
to the area. Poor insulation levels and high air
leakage will make the area hard to heat, drafty and
- Use energy efficient glazing. In some cases, you
may need to install additional ventilation to reduce
indoor humidity levels. If you are installing a whole
house ventilation system, consider one that includes
- Use a licensed installer for heating and
- Install blinds or exterior shading to control
overheating from the sun and damage to interior
- The heating system may not be able to maintain a
comfortable temperature in the living space during
cold windy weather.
- Condensation may damage your work.
- The sun may overheat the living space.
- Your window and door repair or replacement can
provide you with units that are easy to operate, free
from condensation and energy efficient.
- Additional glass area can result in bright,
well-lit living spaces.
- You can improve the security and safety of your
Skills to Do the Job
A homeowner with good fix-it skills may be able to do
some of the work on the repair or replacement of windows
and doors such as:
- Replacing hardware or weatherstripping.
- Repairing caulking or flashing.
- Installing insert type window replacements.
Consider hiring a professional renovator for
structural changes, finish work or complete project
management. If you are doing the changes yourself, you
will still need to hire subcontractors to carry out the
electrical, plumbing, heating and ventilation work.
Remember to obtain all necessary permits, ensure that
workers use safe practices and are covered by workers’
compensation. Protect yourself, your family and your
Use the Window and Door Assessment Worksheet to
record the present condition, any window or door problems,
proposed upgrades and preliminary costing.
Door Assessment Worksheet|
||Present Condition /
|Sliding or Ease of Opening, Hardware Operation
|Caulking and Flashing
|Evidence of Moisture Damage
|Condensation on Glass Surface (during winter)
|Fogging or Condensation Between Glass Panes on
|Door and Frame
|Door Security Features
|Window and Door Finishes
Costing Your Project
The cost of the renovation work will depend on the
condition of the existing windows and doors, local labour and
material costs and the extent of the work to be done. The cost
of doors and windows varies widely. A good budget checklist
will help you to develop a realistic cost for the project
before you start. Some of the items to include are:
Other Useful Information From Canada Mortgage and Housing
Although this information product reflects
housing experts’ current knowledge, it is provided for general
information purposes only. Any reliance or action taken based
on the information, materials and techniques described are the
responsibility of the user. Readers are advised to consult
appropriate professional resources to determine what is safe
and suitable in their particular case. CMHC assumes no
responsibility for any consequence arising from use of the
information, materials and techniques