Over the years, we’ve developed a good
understanding of how buildings perform.
Construction techniques for new homes have
changed rapidly. Most of these improved
techniques also apply to renovations.
If you plan carefully, you can renovate your
home to make it look better, work better, last
longer and be more comfortable. Before
renovating, it’s important to assess the
condition of your home to determine if there are
any significant underlying problems that must be
addressed before or during your planned
In Canada, we need affordable houses to
provide shelter from the elements. We also want
our homes to be pleasant, comfortable and
Homeowners have higher expectations than in
the past, particularly about comfort and
interior design. Renovations are an opportunity
to address some of these expectations.
Some of the reasons people decide to renovate
Upgrade or improve outdated or
deteriorated systems — replacing an
outdated furnace, old siding or windows are
Maintain and repair various elements of
your house — reshingling a roof or
fixing foundation cracks are typical
Address lifestyle needs —
converting unused attic space to living
quarters, add a sunroom or build a home
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
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, ventilating 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.
As you assess your renovation project, ask
yourself how changing particular components will
affect the performance of the whole house. For
example, as part of a bathroom renovation you
may want to add a hot tub that will generate
large amounts of humidity during operation.Your
existing ventilation may be inadequate to handle
the increased moisture levels. It will be
important to provide proper ventilation to avoid
mold growth, indoor air quality (IAQ) problems
and damage to the structure or finishes. You may
need to consult with a qualified home inspector
or a professional renovator.
A systematic and thorough inspection will
help you to assess the condition of your home.
Look for any signs of deterioration and the
possible causes. Start your inspection in the
basement. Many problems in other parts of the
house originate there. Depending upon the size
of your project, you may want to ask a qualified
home inspector or a professional renovator to
help you assess your building and develop a
plan. Here are some of the likely questions that
you’ll want to think about.
Are there any cracks or is there
damage to concrete walls or floors?
Are there any damp spots, stains
efflorescence (white, chalky stains)
or blistered paint on the concrete,
finished walls or floors?
Does anyone notice bad smells or
experience nausea or headaches when
in the basement?
Is there high humidity, any
condensation or visible mold?
Repair minor cracks if they leak.
Seek an engineer’s opinion on
serious structural problems such as
major or expanding cracks, bowed
walls or uneven floors.
Clean up mold; discard moldy or
Ensure that the floor drain has a
trap or install a retrofit backflow
preventer. Make sure that all
plumbing fixtures (including washer)
are vented and have traps. Install a
sealed cover on the sump pit.
Direct outside surface water away
from the foundation. Improve
Repair or replace damaged interior
Keep the relative humidity between
30 and 55%. Ventilate and circulate
air. Dehumidify or air condition in
summer. Clean up mold according to
Serious structural problems could
cause further damage or collapse.
Water pressure on the outside of
the foundation can contribute to
leaks and structural problems.
Odours will continue to be
annoying and can pose health
problems, depending on the source.
Unresolved water sources will
cause renovations to deteriorate
quickly, whether the water comes
from building leaks, plumbing leaks
or high humidity.
Mold can grow on almost anything
and be a source of serious indoor
air quality (IAQ) problems.
or main floor structure
Are there any headroom problems?
Are there signs of rot, sagging
floor joists or twisted beams?
Are there water stains on the main
floor structure or basement finished
Assess structural problems
carefully. Expert help may be
required. Repair or replace
structural elements so they will
accommodate renovation plans and
Fix any water leaks.
Unresolved structural problems,
poorly planned structural changes or
new loads may cause future settling
Are there unusually high heating
or cooling bills?
Are mechanical systems capable of
supplying current and future needs?
Is the house too dry or too humid?
Is the heat uneven?
Is there ever a noticeable smoky
or fuel smell?
Is the electrical service and
wiring capable of supplying current
and future needs?
Do fuses keep blowing or circuit
breakers keep shutting off?
Are there any exposed electrical
wires or crumbled wire insulation?
Do any lights dim or outlets
Are there leaks from pipes, taps,
toilets or the water heater?
Have a qualified service company
inspect your heating system to
ensure that equipment is up-to-date,
functioning properly and sized to
handle current and future needs.
Air seal the house to keep it from
becoming too dry. Use a humidifier
(that has a humidistat) as required.
Provide ventilation using exhaust
fans or a heat recovery ventilator
to reduce humidity in winter.
Dehumidify or air condition to
reduce the humidity in summer. Check
for heat flow to each room.
Repair any sources of smoky or
fuel smells immediately. The smells
could indicate serious fire or
Have an electrician assess the
electrical systems and any problems
such as fuses blowing repeatedly,
sparking outlets, exposed wires or
Repair any water leaks. Repair or
replace leaky fixtures.
Without regular service, heating
systems may gradually deteriorate
unnoticed, leading to serious health
and safety concerns.
Problems can arise if HVAC needs
cannot be met by the capacity of the
services available. The heating
supply must be enough for comfort.
Proper ventilation is needed to
control excess humidity.
Electrical service, wiring and
outlets may be unsafe or inadequate
for increased loads.
Plumbing leaks will continue to
damage the finishes and the house
structure. The leaks may also
contribute to mold growth and IAQ
areas, floors and stairs
Are floors or stairs springy,
sagging, warped or squeaky?
Are floor surfaces damaged or
Are handrails or guardrails loose?
Assess the supports underneath the
floor. Contact a carpenter for help.
Repair as needed.
Refasten or shim squeaking floors
Repair serious safety hazards
immediately such as damaged floors
or stair boards and loose coverings.
If the problem sources are not
fixed, the bulges, cracks or binding
Hiding moisture damage behind new
finishes will cause continuing
deterioration and mold growth.
Faulty windows will eventually
result in damage to surrounding wall
Are there water stains or
Is there black mold on any of the
roof framing or sheathing?
Is the attic adequately
Are there air leaks in the ceiling
of the rooms below the attic? Is the
attic hatch sealed?
Find moisture sources. Repair roof
leaks. Air-seal the ceiling using
polyethylene sheeting, sealed over
octagonal boxes for lights, caulk
holes for wires through sheeting or
wall top plates and weatherstrip
Ventilate the attic at the soffits
and roof peak.
Seal any air leaks in the ceiling
of the rooms below the attic.
Install a sealed attic hatch.
Moisture damage will continue to
deteriorate the house. Unventilated
attics will allow moisture to build
Air leaks in ceilings below the
attic will reduce heating efficiency
and can be sources of odours and
Does the roof have any curled or
cracked shingles, bare patches,
leaks, moss, or damaged flashing?
Do eavestroughs and downspouts
direct water away from the
Repair or replace damaged roofing.
Clean leaves and debris from
eavestroughs every spring and fall.
Extend downspouts to direct
rainwater away from the foundation.
Roofing will continue to
Surface water near the house can
put undue stress on the foundation
and is a primary cause of water
Is there any blistered paint,
rotted wood, buckled siding, stained
or crumbled brick or damaged stucco
on exterior walls?
Find and eliminate the source of
water penetration. Repair or replace
damaged exterior finishes.
Water penetration may lead to more
serious siding, structural and
interior finish problems.
Undertaking maintenance and repair
projects such as correcting
structural flaws, fixing leaks and
making sure that all services are
safe and adequate will make your
home safer, more efficient and more
After you have ensured safety,
efficiency and durability, other
renovations can be done to make your
home more pleasant, attractive and
suited to your lifestyle.
Skills to Do the Job
You can assess most of your house j1
with the help of one of CMHC’s
inspection checklists. Professional home
inspectors are also available to do a
thorough inspection for you.
Repairing serious structural,
mechanical or electrical problems will
require the help of an expert.
Use the House Assessment Worksheet
to record the present condition, any problems
in your home and to help set priorities for
Condition / Problems
Basement Ceiling or Main
Heating, Cooling and
Electrical Service and
Plumbing and Fixtures
Floors and Stairs
Wall and Ceiling
Exterior Wall Finishes
Windows and Doors
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 described.
information has been presented for your
convenience. Please visit the
website for complete information and many more
new home resources.